Wednesday, 16 July 2014

Myths, mutts and misrepresentation

This headline, when it appeared in April 2014, was the best bit of news the purebred dog world had received since Pedigree Dogs Exposed.

It was a report on a new paper from the terrific team at VetCompass looking at the most common disorders in UK dogs. (You can read the whole paper here).

The Telegraph article quoted the paper's main author, Dan O'Neill: “My hypotheses was that crossbreeds would have a lower prevalence of common disorders than purebreds," he told them. "But the overwhelming evidence for that has not been proved."

The Kennel Club was delighted. “The view of the researchers, which we would heartily endorse, is that crossbreeds are not healthier than purebreds," said the KC's Caroline Kisko, who went on to claim: “Over time, we would expect purebreds to go ahead of crossbreeds, because of the amount of research going on into their pedigrees, helping you to get away from health problems.”

As you might imagine, the dog press fell on the report like a pack of hungry wolves.  This from Lee Connor in Dog World (in an article entitled "Don't let untruths go unchallenged") was typical.
"So, that’s that then, the ‘hybrid vigour; lets mix it all up’ theory has been well and truly exploded. Can we now expect apologies from the BBC and from those who likened our breeders and our world to that of the Nazis and the Eugenics movement? Will we now get a big ‘I’m so very sorry, we were wrong’ from the celebrity vets and the RSPCA who have for over a decade championed the mongrel and the designer dog crosses as a healthier, more intelligent pet alternative to the purebred?
In the US,  Dog News claimed too that the paper debunked "the mother myth of them all".


The new paper has even been mustered by Philippa Robinson from the Dog-ED initiative as evidence that the dog-breeding reports that followed Pedigree Dogs Exposed were unfair to the Kennel Club. (See that article here.)

But, of course, this is a classic case of wild over-interpretation by the purebred lobby desperate to counter the evidence that the way we breed dogs within the Kennel Club system is harmful to dogs.

Aha, but you would say that, wouldn't you?

Well yes, that would undoubtedly be my default - and that's because there is just so much evidence that reform is needed if we're going to keep our purebred dogs safe for the future. Nevertheless, having based my stance on evidence, I have got to be open to new evidence even if it doesn't concur with my world view.

So did this paper provide it?

Let me walk you through it and you can make up your own minds.

What is VetCompass?

VetCompass is a UK veterinary surveillance scheme set-up after Pedigree Dogs Exposed - a joint initiative between the Royal Veterinary College and the University of Sydney. Today it pulls data from 100 primary care veterinary practices in the UK representing around 150,000 dogs.

As such, it is an amazing epidemiological resource. No bones about it, you can trust the data.

What was this paper all about?

The paper looked at a random sample of 3,884 dogs to establish the 20 most common disorders in dogs. Here's what it found.

In three of these was there a statistically-signifcant crossbreed advantage - otitis externa (ear infections), obesity and skin mass. And there were no conditions in which there was a statistically-significant purebred advantage.

As the paper explained: "Purebreds showed significantly higher prevalence values for 13 of the 84 (15.5%) disorders and syndromes evaluated. No instances were identified in which prevalence values were significantly higher in crossbred than in purebred dogs. "

So, overall, crossbreeds were found to be healthier (albeit not overwhelmingly healthier). And yet, inexplicably, the headlines claimed that the paper showed that purebred dogs were just as healthy as mutts and that hybrid vigour was a myth.

What the press picked up on was the fact that the authors said they had hypothesised that there would be a more significant difference.

But, actually, it is pretty obvious why there wasn't.

Take a look at that list of disorders again.

As the paper states: "The most prevalent disorders identified in dogs within the current study were complex disorders that have multiple interacting environmental and genetic casual factors."

In fact, some of these conditions don't have much if any genetic component (overgrown nails/obesity/diarrhoea/obesity/laceration/dog bite injury etc). And of the ones that do, most have a moderate to high environmental component.

There is likely to be a genetically-mediated breed predisposition to periodontal disease, for instance - but we also know that diet and dental hygiene plays a huge role in whether or not dogs' teeth rot. Even with degenerative joint disease - which we know is under enough genetic control for selection against it to be reasonably successful - exercise, diet and traumatic injury play their part.

The condition where the greatest difference was seen was "skin mass". Here, crossbreeds were much less likely to suffer than purebred dogs (more than 50 per less in fact - 1.5% as opposed to 3.2%) but given that the category includes much more than just cancer (abscesses, granulomas, cysts and other indeterminate skin lumps too) it's not really possible to make much of a claim either way for that, either.

Clearly, what the paper showed is that the most common disorders in dogs are pretty common across the board (although there were a few interesting breed differences - see below). No big surprise. Dogs are dogs are dogs - fed by overindulgent owners who don't know how to trim nails... prone to cutting their pads on glass.. likely to catch bugs or scavenge something disgusting that will make them vomit.

The authors, too, are concerned about the interpretation of their paper. To help counter the misreporting, they have just produced an infographic aimed at the hard-of-reading.

So what did the paper say about hybrid vigour?


Hybrid vigour- or heterosis - is a phenomenon that occurs when you cross two inbred strains of plants and animals to create offspring that are often superior than either parent - more robust, bigger, stronger, more fertile, more fecund and longer-lived.

None of these traits was measured in this paper. It did not look at the severity or duration of disease, for instance, or at survival times for the more serious conditions .

In fact, while hybrid vigour has been very well documented generally, it hasn't been studied much in dogs - and neither has what many refer to as its opposite: inbreeding depression. No one, for instance, has looked at what happens to litter sizes or neonate mortality as inbreeding increases (although there is some anecdotal data).

But there is some longevity data - and most recently from the same team behind the disorders paper paper.  Last December,  VetCompass published a paper looking at longevity and mortality of owned dogs in England and what it found was unequivocal. Although Miniature Poodles, Border Collies and Jack Russells lived the longest, overall, crossbreeds lived 1.1 years longer than purebreds - around 10 per cent longer. This echoes most other studies.

The authors concluded: "The findings... support the concept of hybrid vigour in dogs" - as noted on another infographic they've just released.

In conclusion...

This is a good paper in many respects. It highlights, for instance, just how common ear infections are in dogs and it suggests that we we should expend more energy working on the 'less sexy' disorders because of their high prevalence.

It also highlighted some hitherto unknown and interesting breed differences: Cavaliers, for instance, were found to suffer from a high rate of anal sac impaction - another 'low grade' problem that might not make headlines but is nevertheless significant because of the number of dogs involved.

But did it tell us that purebreds are "as healthy as crossbreeds" - or that hybrid vigour is a myth?

No, it didn't.

Most importantly, the over-arching scandal in dogs remains the breed-specific disorders that plague individual breeds as a direct result of the way we breed dogs under the current Kennel Club system:

• selection for looks over health and function
• inbreeding
• popular sires
• the damaging obsession with purity for purity's sake
• the myth that you can health-test your way out of trouble

And this is why...

• 30 per cent of Shar-pei suffer from Shar-pei Fever.
• 50 per cent of Cavaliers have a heart murmur by the age of five
• more-than 50 per cent of Flatcoats are dead from cancer by the age of 8/9.
• a horrific number of Dobermans drop dread from dilated cardiomyopathy
• so many Pugs and Bulldogs have to fight for air their whole lives

...etc ad nauseum

None of these conditions featured in the Top 20 Disorders list because they get lost in the numbers when you lump all breeds together.

But no one other than a fool would suggest that they don't matter because it turns out that - overall in dogs - the most common problem is an ear infection.

The authors stress that they think we would be better served looking at individual breeds rather than getting too hung up on the crossbreed v purebred debate - and I agree, although only partly. And that's because the evidence that crossbreeds live longer and are healthier overall (even if only marginally when it comes to the most common disorders) is important. 


Because understanding why - despite all that selection in purebreds, despite all that health-testing - is critical to improving purebred dog health, to safeguarding the breeds we love for the future.


  1. Wow, cool blog entry. The trouble with a paper like this is that it is asking the wrong question. Again, there are two main intrinsic (non-environmental) factors affecting dog health: 1) morphology and 2) genetic diversity. Both must be of high quality to ensure good health. You can't have a morphologically sound dog with low genetic diversity and expect it to be healthy. And of course, a morphologically unsound dog is not going to have high genetic diversity, anyway.

    So, the question these researchers posed was far too simplistic. Instead of asking, "What is the difference in non-environmental health between pure and mixed dogs?" they should have asked, "What is the difference in non-environmental health between ancestral and derived dogs?"

    In other words, I want to see a study comparing on the one hand ancient types like huskies, laikas, INDogs, Carolina dogs, and even mixed working and sporting dogs, vs. any number of toy and non-sporting dogs, and even purebred working and sporting dogs. I betcha the results there would be much clearer: the ancient mixed types would be far and away healthier than the modern pure types.

    1. Yes Gaddy. Desperate times call for desperate measures.

      Jumping onto a survey of very common general dog ailments to shout out that pedigree dogs are as healthy overall than cross breeds is grasping at straws to try and stop a landslide of public awareness of just how incredibly weak and unhealthy many pedigree dogs are in the main.

      I have to say Dan O'Neill is a bit of a nutter:

      The paper's main author, Dan O'Neill: “My hypotheses was that crossbreeds would have a lower prevalence of common disorders than purebreds," he told them. "But the overwhelming evidence for that has not been proved."

      Wow he set out to find out if all dogs are equal as far as common ailments are concerned? If a dog is a dog?

      This is like "discovering" all children get runny noses from time to time? Then saying third world children are as healthy as Western children because they also get runny noses, pink eye and mumps.

      But what of TB, rotavirus, malaria, typhoid etc etc etc.

      VetCompass may be a fabulous organisation but this survey was a complete waste of time. I have to agree with Georgina.

      I think a survey of pedigree dog ailments overall, all their ailments genetic and environmental compared to cross breeds might have been a tad more interesting.

      Wonder if they think pedigree dogs are a different species to cross breeds, that they thought they needed to discover it for themselves with a survey of common dog ailments?

      Whacky hypothesis. No?

      The results of the survey are as meaningless as the translation by the pedigree dog lobby.

      We knew them all along. Oh IC the common cold is common oh gosh. Headline stuff.

    2. The study design is flawed. It's just not asking the correct question - what is the prevalence of genetic diseases/disorders in specific breeds of dog compared to crossbreeds and/or mixed breeds'.

      Sure, it's interesting but not particularly helping us get at the heart of the issue.

      They could have looked at the prevalence of genetic diseases within the individual breeds and compared this to the mixed breed or crossbreed cohort. This would have been much more useful in addressing the problem.

    3. Yes that would be interesting but I don't think it has to be "specific breeds" even to be a lot more worthy than what it was.

    4. Why refer to him as a 'nutter' though? It's really not helpful to insult people like this. His hypothesis could also have formulated on how he sourced the data. Prevalence just means how many dogs within the population will have a disorder/disease at any time. You have to take into account variables such as which people are more likely to take their dog to a vet than others when sourcing data such as this. it's a study that isn't addressing the root cause of the issues debated on this blog, however, good science means that people will look at this, criticise it (see Jemima's blog post) and hopefully build on it. Science is mostly ABOUT failure actually. It's like anything else in life, it's how you react to stuff that defines you.

      Criticise it but be constructive. That's more helpful in the long run. How would you define a study that would look at outcomes as to how prevalent genetic disease is in pedigree dog breeds as opposed to crossbreed or mixed breed dogs?

    5. Re reading my blog and JH's retort I may have been a bit rude but I do feel that the information is, as RiverP states, as good as discovering children suffer from colds. The information shown would only be useful in reality, to drug companies who would want to know where to aim their next research and development policy for say ear drops, eye cream etc etc for the next couple of years. I'm sorry, but I still feel that all of that energy, all of that thought, all of that reporting would have been so much more useful if it had been about serious inherited conditions appearing in pedigree dogs, big breed, small breed, age, activity, big, small, age, activity crossbreed and likewise mongrel. Hopefully age, development in big, small, activity would be at similar growth stages thus trying to give a true comparison (well as near as possible). It would be really useful and worthwhile. It would also be a good "stick" to hit the pedigree dog breeders with and Kennel Club if they could see and really understand the true damage being bred into pedigree dogs. Assuming, of course, that the stats show that pedigree dogs are in a worse state than their counterparts. We may be pleasantly surprised that peds are, in reality, quite healthy but we won't know for sure until a serious survey by unbiased, factual seeking bodies is undertaken, Vetcompass, fancy it?????

    6. The only thing it seems to have served is the apologists in the dog showing and breeding world, fuelled by O'Brian's voiced personal failed hypothesis.

      One can only hope that between the Royal Veterinary College and the University of Sydney (silly little pictograms aside) that they can come up with something a little better following this yes.

      Remember this survey was to "identify the most common conditions affecting "dogs in the UK", not to discover if pedigree dogs were healthier than cross breeds.

      However Nutter O'Neil made his statement as one of the main authors of the "paper" :

      “My hypotheses was that crossbreeds would have a lower prevalence of common disorders than purebreds. But the overwhelming evidence for that has not been proved."

      Yes it has got people talking but so far except for Jemima about all the wrong things.

      While this might not appear to have been O'Neils aim if seen as a pure bit of useless scientific data gathering, which it is, but it comes pretty damn well close if taken along with his personal statement about his hypothesis and the result of the "paper" he was part of producing.

      Im not sure if you are the same Nonymouse as 10:08, but "nutter" is not much of an insult in the English speaking world its a relatively friendly "insult" and not meant as anything more. (:

      Quite frankly I don't need convincing on the issue of pedigree show-dogs and their out casts versus cross-breed vigour or simply domestic dog versus pedigree show domestic dog. It's the breeders and showers of deformed unhealthy pedigree dogs that do.

      I would expect a "watchdog" organisation set up primarily by vets to monitor pedigree dogs to come out condemning in no uncertain terms line-breeding, inbreeding and a whole host of other breeding practises from adverse colour breeding to breeding for extremes and fixed standards that lead to utter misery in our best friend the dog.

      They can and are in a position to collect all the data they want on breeds and pedigree dogs as a whole to back themselves up, even if it's already starring everyone in the face.

      Some people will never be convinced certainly trying to convince those with vested interests in the dog showing world is not an easy task, and yes this includes vets. Most definitely vets do have vested interests pedigree dogs are often their bread and butter.

      By the way the Veterinary council of Australia still does not advice three yearly vaccinations!

      However O'Nutters voiced and failed hypothesis doesn't help at all even within the confines of his and the others involved extremely limited in value data gathering exercise.

      Im not sure how this data is meant to have any value to contribute to VetCompass's functioning as a "respected" pedigree dog watchdog organisation?

      It doesn't, and as such it is true it is a waste of finances and resources. The same information and results could have been achieved with a chat with any local vet over a beer in a pub.

      In my opinion but of course.

    7. River P and Georgina

      Your pompous retorts are the EXACT reason why the dog fancy will continue to alienate itself from reform. I really don't think you have any empathy for anyone else who doesn't think like you do.

      So, you seem very confident to criticise this study based on the fact that they are not looking at the area of interest of genetic health in pedigree dogs vs crossbreeds, even though it never set out to do that in the first place. Can you criticse that in a way that makes scientific sense to us?

      And, importnatly, can you offer an alternative study design and/or hypothesis that would honor Vetcompass' resources, remit and also provide the evidence that you so desperately seek?

      Otherwise, you're just whinging....

      I'm bored now....

    8. Anon 2207, I have already outlined that the resources, the time, the intelligence, the finances, the genuine concern for the wellbeing for dogs by Vetcompass would have been much more worthwhile and informative if they had taken on the inherited conditions that affect pedigree dogs. I have even suggested a framework which would need more intelligent input than I can offer, but a frameworth nonetheless. And your suggestons are? Inherited conditions caused by ignorant breeders who have their eye on the cash and their inflated egos that they know exactly what they are doing with another species matches your wording above. Again, not all breeders thank goodness, but they are in the minority, it is the people who adopt the same opinion as yourself who cause the most damage to dogs. You have clearly not read either mine or RiverPs blogs. A study of the ilk they have undertaken is the sort of study needed by pharmaceutical, drug companies for their future R&D. As such it is fine but uninformative for those who are seriously worried about the future of pedigree dogs, in fact all dogs. The conditions researched outline careless animal husbandary. And, may I say, your retort is not only pompous, but rude.

    9. Georgina, I am not sure what you're not getting here - or why you continue to insist that the study is worthless because you wanted a different study.

      Again, the whole problem here is that the purebred dog lobby chose to over-interpret the study.

      There is a whole host of data to come out of VetCompass; it is an amazing resource and it will continue to publish for, hopefully, many years to come.

    10. 'Inherited conditions caused by ignorant breeders who have their eye on the cash and their inflated egos that they know exactly what they are doing with another species matches your wording above.'

      Er. I'm lost now.....

      If you are serioualy worried about the future of pedigree dogs then try to that in order to get the very people to do the thing that you want (which is?) then you need to win them over and show evidence and compassion. It's a basic psychological premise...

      You've basically just slagged off vetcompass (for doing something worthwhile, if not in line with what YOU want) and you don't seem to understand that they need to have an effective and appropriately powered study design in order for a study to be of any use in the first place.

      It was the Telegraph that screwed it up!

    11. No JH, you miss my point. My point is that a lot of people have put in a lot of research using resources that these days are scarce and expensive that could maybe have been used in a better way. I didn't know that Vetcompass was undertaking this research and nor do I know what they have planned for the future. It just seems to me that this particular research is so basic it is as someone else has said, like identifying that children catch colds. The information is so obvious, not earth shattering, nor informative for the average dog owner, we know dogs have ears, eyes, nails, skin etc, we know that if they are neglected then a trip to the vets is on "the cards". That our dogs will suffer discomfort because of our neglect. I was surprised to read it because I have learned so much about other breeds and breeding practices from this site, but this article has gone completely over my head from a "learning experience" pov. Perhaps it needs breaking down and you could explain what it is you are trying to portray and why it was important to put it up on the site.

    12. Georgina, the blogpost is purely to counter the stupid misinterpretation of this study by some in the show world. The intention is to point out why they are wrong.

      One point being missed, btw, is that there were breed differences in those disorders with a high environmental component - e.g. who would have known that Cavaliers have such a problem with their anal glands (well, other than Cavalier owners, perhaps!).

      That ear infections are such a problem - and they are often painful - is also interesting. Perhaps there's more to be done to help prevent these. I've also suggested to VC that they might explore if prick-eared breeds suffer less (as is commonly suggested) and if, say, it was found that Bassets are hugely over-represented when it comes to ear infections it would provide some basis for a change in the breed standard (towards lighter, shorter ears).

      That we now have a baseline is also important - and a benchmark too perhaps. One in 10 dogs suffering ear infections sounds quite a lot to me. And yet we know that some breed specific disorders are way more common that that.

      This paper, at the end of the day, isn't earth-shattering because it doesn't tell us something very unexpected or ground-breaking (despite what some people thought). But it *might* have done.

      Data is good. Even when it confirms what we thought.

    13. I think it makes perfectly reasonable sense to be questioning VC's motives after O'Brians statement!

      Far as we can make out it was he the leading contributor who muddied the water perfectly for the entire show world's apologists to leap in head first.

      An open invitation to a mud orgy.

      As it has been repeatedly pointed out the initial paper wasn't to discover if cross breeds where more immune than pedigrees to common ailments?

      "Common ailments" its worth repeating that, but rather to discover what those common ailments are in the whole pet dog population.

      O'Brian is surprised to learn a common ailment is a common ailment that's why he is an out to lunch nutter.

      It has very little to do with pedigree dogs or mixes. But there he is expressing his surprise that his hypothesis was wrong and in no uncertain terms bolstering the showing lobby apologists.

      Its absolutely justified to be questioning the motives of VC at this stage. No question about it.

      Are they nothing but a bunch of pedigree show dog apologists or not? Fair question, maybe we cant tell yet, but after this its more than reasonably justified that we should be cautiously wary.

      Completely off topic, but we know already a lot of so called "environmentally" caused ailments in pedigree dogs are in fact due to bad breeding practises. Most definitely. Unfortunate "mutts" who happen to inherit the same phenotype intentionally selected for or not are going to suffer similarly of course.

      Could this mean for example it's the pure vanity of human beings to be preferring (selecting for) hang ears over natural prick ears or lightly folded that is causing ear ailments to be so common in dogs?

      Very likely. As likely as it is for dogs that are so badly formed they cannot exercise sufficiently to naturally wear down their toe nails, or use their hips or breath.......

      Thats my hypothesis and Im unanimous in that. (:

  2. Also, you can't just automatically mix two breeds and say they have heterosis (hybrid vigor), although many people think that. For instance, you can't cross a pug with a Cavalier and say, "Oh cool, this dog is no longer inbred." On the contrary, it would take many generations of back-crossing such highly altered dogs with more normal pariahs, spitzes, shepherds, and/or retrievers to return to a healthy domesticated wolf.

    1. You also have the problem of closed off breeds developing genes that work together to overcome their disadvantage.
      Mix a brachycephalic breed with a non brachy & you may get a dog who's features do not work together well ( cavaliers were a mix of toy spaniel , papillon and springer/ cocker .They are a mess of jumbled teeth & palates that are too long for their muzzles, as well as deformed skulls , and narrow ears, They are certainly in no way an improvement on any of their ancestors. )

      The same for mixing a short legged dog with a long legged one. etc The jumble of different body parts and growth rates may be a disaster.

      It would take years of work to straighten out all the issues

    2. Er no. That's simply not true.

    3. Anonymous, I also disagree about the existence of some sort of "suite" of characteristics that work better together. With few exceptions, the more you alter the canid body plan, the more you weaken it. To some extent, smaller size and shorter legs are helpful for hunting badgers and rodents underground. Somewhat shortened muzzles and broader faces do increase bite strength in molossers. But all of these traits have been taken to unhealthy extremes in dachshunds, bassets, pugs, etc.

      But in general, backbreeding altered dogs (and other animals) to look more like their primitive ancestors results in improved health. Again, I'm not advocating that people keep wild wolves in their homes. I'm just saying that dogs are domesticated wolves, and should look more or less like them - and have something close to their genetic diversity - or their health will suffer. This study totally ignored this phenomenon by creating a false dichotomy of "pure vs. mixed" dogs, and as Jemima pointed out, by conflating genetic disorders with environmentally induced ones.

    4. Anonymous 22:09 The problem in breeds such as the Cavalier are the way they have been bred their genes are not working to overcome the way they have been bred and they are disadvantaged by the genes they have, they don't have genes to overcome the disadvantages bred into them, that is the problem.
      What happened with Cavaliers was that in 1942 they were separated from the King Charles spaniel with only five stud dogs registered. After 1942 no outcrossing has been done and trying to lengthen and keep the nose lengthened has been done using only five male ancestors.
      All the brachy breeds suffer with dental alignment, soft palate issues, deformed skulls and narrow ear canals. Having crossed out this breed, I know from personal experiencethat the problems can soon reverse themselves and the risks of health problems with offspring in crossing this breed carefully are less than pure breeding this breed.

  3. Also, it's a myth that "breeding away" from genetic disorders completely compensates for purebreeding and linebreeding. It may mitigate the effects of inbreeding depression, but it cannot take the place of a larger, healthier gene pool. I've corresponded with a lot of breeders who simply deny this fact. Without some outcrossing, purebred dogs - particularly those with highly altered morphology - are necessarily going to be less healthy than primitive and mixed dogs with normal morphology and higher genetic diversity.

  4. Did you mean "Myths, mutts, and misrepresentation" or "Myths, mutts, and miscegenation"? -- Rod Russell, Orlando, Florida USA

  5. Regardless of which is healthier, the argument for more considered purebred breeding still stands. If you breed deformities and health issues into purebred dogs through inbreeding and inappropriate selection there is the potential for these traits to be passed on to all dogs, whether purebred or mixes of these purebreds. In other words, poor breeding ruins all dogs.

  6. hybrid vigour and inbreeding depression do need much more research, in conjunction.
    This pure bred versus cross bred mentality is likely the biggest danger to dogs today, because it has deflected focus and discussion away from best breeding practices and management as a community, by its division.

    Neither pedigree or mixed breeding is 'THE' right way to breed for the purposes of the communtiy. It requires a balance.

    Bottom line, the effects of inbreeding will effect us all, sooner or later if the K.Cs don't allow their own members to cross breed out side of the K.Cs charter.

    This would give K.C members an avenue to understand and cater to what the COMMUNITY wants in dogs, But also, allow community an avenue to understand better breeding practices and selection for specific goals and purpose (and health.)

    Concentration of lines will affect our mutts as well as our pedigrees as long as concentrated lines are being introduced in breeding them. The way the K.Cs are taught to keep their best dogs out of the hands of the public ( and BYBers) those that do make it entire into the hands of those who might use them, are likely to be from less knowledgable or more unscrupulous breeders.....So that in general, only the poorest quality pedigree dogs make any contribution to cross breed dogs over time and any hybrid vigour itself declines.

    Symptoms of inbreeding depression do not dissapear magicaly in the 1st generational cross., especialy in more severe cases. You may actualy get totaly new problems. I've often seen neurological or mental issues appear. I assume because the concentrated genes mixing with totaly new ones may intrduce incomatible genes that have not been seen in the concentrated lines before or in living memory.

    Pedigree breeders tell us that introducing new lines can be very detrimental. They may even end up with more problems and have a lot to lose. This will be more true the longer it continues.
    But it seems to be forgotten that "mutts" , with the introduction of these same pure lines, will also decline and maybe more rapidly than the pedigree dogs themselves while its mainly inferior dogs being used in their breeding.

    Domestic dogs are a single species. In the single environment of our communities. Any semblance of a balanced system are being destroyed by an artificial division.


    1. Best dogs kept back for pure breeding does not equal healthiest dogs in the pure world and the same goes for what a pure breeder might consider is an inferior dog often can be more healthier dog.
      Inferior in a pure breeders ideology is it does not fit their idea of close enough to a man-made breed standard and often does not reflect the health status of the dog.
      Most pet pure breed dogs are the ones that are sold off because they are seen as inferior to the pup they retain from the litter.
      It would not be the poorest quality dogs in health terms being used in cross breeding, more often it is just the dogs pure breeders don't think fit the breed standard well enough.
      Mutt's will always exist, they were here before pure breeding and will be here long after. Genetic studies show mutts have much higher levels of genetic variation than pure breeds and that alone is enough to ensure their survival past pure breeds.
      Dog breeding needs to see pure, cross, mixed breeding as tools to breeding healthy dogs and although you infer this you don't seem to understand that pure breeding needs mutts more than mutts need pure breeding. I would love to know what you define as an inferior dog ? The word "inferior" is a very inflammatory term to use, one to often used by pure breeders.

    2. No, In pedigree breeding 'best' kept back does not always equall healthiest. But a breeder who is concerned about health enough to do all relevent testing for their breed, and takes into account temperament and all other relevent traits for a good reliable dog is far more more likely to to place their dogs with other, responsible pedigree breeders - As oposed to a breeder who does no health checks, has little idea of what their own goals are beyond being able to say they are a K.C registered breeder, and has no real sense of responsibility attached to that.

      I understand very well that pedigrees need mutts far more than mutts need pedigrees. But until thats accepted by the general population as well as the K.Cs, BOTH will decline in health and mentality. The genetic variation in mutts won't absorb and nullify problems completely and indefinitely.

      As for mutts surviving long past pedigrees, I disagree. Only as long as there are pockets of landrace types and "camp dogs" un affected by more urban values and legislation will tthat hold true. As long as there are populations of dogs unaffected by all this crap of pedigree Vs mutt, they will survive......when thats no longer the case it will likely be all over. It is a single species called domestic dog and there are ways to maximize results in breeding to ensure the dogs evolve and improve according to community demands. But no one is discussing that honestly or un biased while the debate about pure or cross rages and both sides resort to calling for legislation and restrictions to solve the problems that result.

      With out this" war" we would have dialogue about how to be better owners and breeders, rather than who is doing it wrong and needs censure.
      We devalue dogs in the eyes of the community when we only point out whats wrong with breeding / breeders. If we concentrate on whats right, we add value to the species.But thats not discussed with out severe predudice.

      When I said inferior dogs used in breeding crosses, I meant those pedigree dogs bred with no thoughts beyond the production by breeders avoided within the K.Cs. Their dogs are more likely to slip through the K.Cs boundaries.

      But until there unbiased discussion of what exactly we are breeding for, and how best to achieve that, what people want and expect of breeders and the dogs we keep,that type of breeder is not confined to pedigree circles either, Not by long shot.

      With out honest, unpredudiced discussion of what ails DOGS we have no alternative but legislation and restriction for dog ownership/breeding.

      Heaven help us if we were to take the same attitude to say, parenthood.Imagine dividing parenthood into two warring sides, devalueing and censuring each other rather than allowing a natural, evolving balance ruled by community values.


    3. I am a cross breeder and buy in pure breeds to my lines from reputable pure breeders who do all you think a reputable should do.
      When I said, "Mutt" I meant anything other than a pure KC registered dog, sorry for not be more specific.
      When you say KC boundaries, could you explain what boundaries you mean ?
      I actually think legislation here in the UK is the way forward for dog ownership and breeding.
      Parenting is legislated in the UK with laws about education for children, a child working and care of a child, even down to breeding a child, with incest being illegal. Even things like having to belt a child in when in a car is parenting being legislated. We have lots of laws legislating parenting in the UK and believe me parents can be very warring and devaluing about other parents, often the dividing factor is of a religious nature.
      In the UK I personally think very careful, thought out legislation for dog ownership and breeding would be a good thing, maybe not for breeders, but for the dogs. Where we see tighter laws for dog ownership like in Scandinavian countries we see less problems with dogs, from behavioral problems to stray dogs.

    4. Boundaries of the K.Cs: - The K.Cs have ruled that no member may breed a dog that will be eligible for registration. Therefore they have demanded that members work ONLY within the registry. That is their boundary. K.C members may breed only pedigree dogs.. No out side influence is permitted near what they do.
      K.C Breeders, like the dogs they breed, are a closed population of people bound by that rule. Like the lines they breed, that rule defines them as separate, and concentrates in their population over time.

      Breeders operating out side of that belief are censured and so a judgement has been passed.
      If the goal is "betterment" or "improvement", and members are expressly forbidden from mixing lines, mixing lines must be antagognistic to those goals.

      Unless approved by the parent body and conducted in such a way that that resulting dogs will be recorded for possible inclusion into the parent breed, or a new breed with a pedigree, it won't happen. A long, tedious, drawn out process with no guarantee of approval or acceptance. There is nothing spontanious or experimental about mixing breeds within the K.Cs. Its expected that that will be done only after as many factors as possible can be predetermined, for predictable results.

      In other words, there is no random, individual or communty influence on breeding dogs within the K.Cs. They allow no "environmental" influence. They are a closed environment, unto themselves, with clear boundaries - As a breeder, you are a member abiding by their rules, or you are antagonistic to their goals.

      The 1st requirment of quality worthy of being bred becomes a pedigree. Reliability is replaced by predictability.

      The K.C environment is one that actively promotes a belief among themselves and the community that mixing lines is in itself some how unethical.
      Quality and reliability are environmental constructs. They can only come about through meeting the needs of the environment.
      In the case of pedigree dogs, that environment isn't Us, the community who keep dogs (as it should be) because the K.Cs own closed environment calls all the shots. Members are pressured to appease their peers before meeting any needs from the broader environment.

      Yes, there is legislation governing parenting.... But it governs all parents equally where its in place, for a community who aknowledge a common goal in child welfare and safety.

      There is no parenting group trying to claim exemptions on the basis of their members better record, or attempting to discredit the legitimacy of parenting outside of their own belief system. Its recognised that we, as a community share a common responsibility and goals.Legislation and Peer pressure to acheive good results is more effective because it comes from the whole environment working together, for common GOALS. Not to censure of opposing groups or beliefs.


    5. Unfortunately the world has communities not a community, so a common goal for one is not the same for another and a common goal for child welfare and safety is often conflicting within community let alone communities, unless you live in some utopia, we are all unaware of and why legislation is often then passed, if conflict did not occur and we all agreed why, we would not need legislation, but unfortunately we don't.
      One minute though you imply legislation is a bad thing, but now seem to of changed you rhetoric on that by saying "legislation and peer pressure to achieve good results is more effective."
      Basically what you are saying is the KC's boundaries are a closed shop and unless you sing from their hymn sheet you will be excluded, which I agree with you on and know only to well about and they are only a registry and that is what people have to get their head around which is happening. Dogs will not fall apart without a central place to register ancestry. Dogs don't need the KC, the KC needs dogs.
      Love to go into this further and pull further points with you as I think we have a similar thinking on dog breeding, but I get annoyed when people generalize dog breeders and you generalized cross breeding as people generally breeding from inferior dogs which is never helpful for those of us trying to break through the barriers.

    6. Aussie forgot this little bit. When I decided to cross breed, as my cross breeding is not to create a breed (I now think in type, not breed), but to breed a healthier dog similar in some aspects to the breed, I approached the KC and realized that although they seemed keen in what I was doing, this was not the case for the breed club, I have never got on with my breed club for my breed and is reflected in the fact that I have never been a member, even after applying (must of got lost in the post) and although I think the KC is at fault, the power is still held by breed clubs. Slowly the KC is being infiltrated by progressive people who know that cross breeding needs to come into the KC tool kit for breeding healthy dogs, whether they will be able to progress fast enough away from the clutches of the breed clubs, I doubt though.

    7. On the same page anon.

      "The world has communities, not a community" I agree, which is why results vary on locality with regards to legislation and some countries have much better results.

      Some legislation is always needed, of course, and there will always be some who disagree with any piece.
      The point I was trying to make is the legislation path is needed far less when there is a semblance of unity in the target group to allow for discussion and acceptance of common goals and purpose. Given time, peer pressure can nullify the need to resort to legislation as the automatic response.

      I also get very annoyed with generalizations and labels. I did not intend to imply that those who cross breed generaly do so from inferior animals. I am in the same boat as you are: Breeding crosses that at one time, I had stupidly hoped could be re-introduced into the parent breed to over come some of the many problems showing up there.

      BUT if people like us are honest about what we are doing, it would be a rare breeder who would make our 1st choice of pedigree dog available for our use in these programs.
      While pedigree breeders pressure any one with genuine goals to proceed only under the K.Cs umbrella, or be seen as unethical, our own ranks loose a lot of expertise. Either because people 'defect" or because its all made so difficult.
      Knowledge becomes concentrated in the K.Cs and either lacking, or dissorganized out side of the K.Cs. ( and because whats outside of the K.Cs is the environment they draw new membership from, their own knowledge base deteriorates and concentrates)

      The K.Cs, In passing judgement on mixed breeds, practices a form of suppression or oppression.
      If pushed, I would have to say there likely is a higher proportion of "thoughtless" or uninformed breeders among people who aren't signatory to the K.Cs charter. As a result, a lot of dogs that aren't the best to be breeding with.
      I don't blame those people though. The way I see it, the K.Cs ruling against cross breeding actively oppresses an understanding of dogs and the breeding of dogs unless it occurrs under their own charter. That ruling is not consistent with a registry only. Its a judgement and political statement thats set the organization into an antagonistic relationship with the environment that gave rise to them- People breeding dogs to suit their own purposes and expectations. As long as that ideal is under attack, So is the relevance of dogs.

      The direction domestic dogs as a whole have taken is predictable, according to natural and biological laws.
      If you have a organism that tries to close itself off from an environment it sees as antagonistic to its goals, it can only shrink and tighten as it is forced into a state of constantly rejecting and defining itself against its own environment. That organism has created its own, sub environment, but its a false one because it can only shrink with out the medium that gave and gives rise to it.

      Its the same with an organisation. Its demonstrable. And such a situation does not only affect the organism itself, but the environment it exsists in. The one gave rise to the other in a give and take relationship and that relationship changes as we see happening with domestic dogs.They are loosing relevence and value in their environment and it gains momentum.

      You can easily point out differences between pedigree breeders and those who cross breed. If you want to generalize, they ARE there but as far as I am concerned its a single species dependent on a single environment thats under attack. We share a common environment so no problem or bennefit can be unique to either pedigree dogs or crosses. The way I understand it requires an wholistic approach and the K.Cs stance on cross breeding stands in the way of that.


    8. It is possible to get permission to do an outcross to another breed from the KC. Failing that, it is possible to get a dog of 'unverified parentage' recognised and brought into a breed's gene pool, as long as it looks sufficiently like that breed. In some specific circumstances, for example the ISDS registry for collies where the KC will register any dog registered with this registry, it's possible to even bypass this and get dogs in through the back door. A friend of a collie person I know has a collie from a bitch who was bred by accident under 1 year old, and the KC would not register it. It has now done whatever it needs to do to be registered with ISDS so now the KC have to register it.

    9. That is the hilarious thing with the KC, if you find a dog and it looks like the breed enough without any ancestry known, you are more likely to get it registered as a foundation dog with a breed than following a careful cross breeding program, doing all expected health tests and knowing ancestry of dogs.
      So if crossing to bring in more genetic variation and better health, your best to just tell the KC that you found your carefully crossed dog and you don't know it's parentage but think it might be a pure breed and you will stand a better chance of getting it on your breed register.
      The KC make me laugh with this because one of their points of selling you pure breeds is the fact you know it's parentage and thus offspring are more easy to predict, but they seem more happy to let dogs with unknown parentage on the register than a carefully bred cross, unless the cross of course is for bobtail, then come on in.
      You don't need permission to cross from the KC, only unless you want a piece of paper saying, "KC registered" Lol

    10. Possibilities to get impure dogs registered is good, no doubt, Though I feel its far too stringent and again, depends not on what "we" want, but on what the relevent organization will accept.

      I doubt that applies equally here, or to my "breed" and I would not be interested if I'm forced to go through a back door. If I can't do it openly and honestly its not for me.

      If I were to breed dogs for MY purposes and goals, I have no interest in that enterprise being over seen by some distant committee that has no intimate knowledge of my dogs or purpose and whos judgements are not formed by any recognition of purpose or reliability.

      A committee whos judgements are coloured by limitation to whats predictable and known.

      Whos competions to determnine quality or improvement are based only on what in front of them now, from stock selected as 'Best" generations ago and only ever compared to their generational peers ever since.

      The piece of paper is irrelevent to me. What bothers me is the K.Cs encouragement to Judge on that alone.To see such breeders as unethical because there is no pedigree attached...Not for poor breeding choices, not for poor husbandry, welfare or health reasons.

      Simply because its not done under their guidance, when their own breeding programs can no longer meet my needs or those of the broader environment and instead ask us to accept more and more limmited versions.

      If registered breeders were permitted to cross breed honestly and openly with out judgement, the needs of the environment could be met and SUSTAINED, instead of supressed.

      Registered breeders could discuss best practices with out the clear biase against dogs that are unpapered because they would no longer be considered antagonistic to their own goals, but complimentary.Cross breeds would no longer be completely outside their bounds. The consumers ( or environment) would benefit from more open discussion of goals, purpose, husbandry and relevent testing.
      The breeds/breeders would benefit from the understanding gained by breeders of the communities priorities and requirements, their 1st hand knowledge and understanding of effective crosses and lines. Pure breeds would be compared more often to successful deviations and debate about total out crosses would be taken more seriously and open mindedly because there would be dogs ready available to consider on their merits, bred by their own "ethical" membership.

      Environmental demands are given an avenue to be heard and met, while the environments responsibilities to the dogs will also become more clear with out the barriers of one from the other.

      Pedigree dogs are the RESULT of thoughtful breeding practices. While that ruling against cross breeding exsists, we are being taught instead that pedigrees ARE thoughtful breeding practices.


  7. Wasn't this study funded by the KC? If so, that is possibly why they focused on ailments that don't have a genetic cause in the main (such as the above), and ignored those where a genetic cause could clearly be implicated and will shorten the dog's life e.g. heart diseases (MVD) and cancer.

    1. Fran this is a completely unfounded and unwarranted slur on the researchers and it's obvious you haven't read the paper. Please don't start *another* myth. No, this study was not funded by the KC and if you read the paper the methodology is clear. VetCompass pulls in data from first opinion vet practices. The Top 20 disorders were the Top 20 disorders. You'll note above that I say that you can trust the data.


    2. The data is sound but it it frustrating that they wouldn't have done a better job of accounting for the fact that a lot of these top 20 are not really separate conditions. Vomiting and diarroea are symptoms of gastroentiritis, not conditions in their own right. Listing traumatic injury, claw injury, bite injury, and laceration separately seems absurd to me, especially considering they are all environmentally caused and part of the intent was to look at a difference in health caused by genetics. Why not group redundant listings and get a more revealing top 20?

    3. You're right, I hadn't read the paper and if I had it would have made my comment redundant. However, my presumption was based on the belief that the KC's Charitable Trust were funding Vet Compass from this blog post. And it was a criticism of the KC, not Vet Compass:

      However, wrt to my frustration with the study, I agree with CJames. The study hasn't told us anything revealing about dog health.

    4. I don't know who supports Vetcompass financially but if it was me I would want to know why they thought it was ok to use my money to present such a load of useless rubbish. If I were Vetcompass I would be embarrassed to put my name to the above research. They could have used their time more sensibly: Contact vets in as many of the regions across the UK and ask for their participation. Contact the pet insurance companies (who probably already have the true stats on health of pedigree v crossbred v mongrel). Ask the vets to collect information for say a month on the breeds and crossbreeds of serious conditions i.e. hip dysplasia, entropian, epilepsy and all of the other horrendous conditions our dogs have to live with because of bad breeding. Age of dogs, whether house dog/kennel dog, general condition of dog, i.e. whether muscled so obviously excercised. I know gundogs that are so soft it is criminal just to protect their joints, coats etc for the show ring. Something of this ilk would give a possibly more accurate overall picture than the nonsense above. For me and I think most of us now, though we love our breeds but have become much more learned and aware of the plight of rescue dogs and the shocking breeding practices of alleged dog lovers who are blinkered by their drive to win a silly piece of cardboard. The damage they have done to dogs is cruel.

    5. Georgina, what on EARTH are you talking about. Are you aware of how VetCompass gathers its data?

      What precisely do you think was "rubbish" or "useless" about the research.

      The paper set out to establish what the most common disorders were in dogs - across the board and whatever their provenance/cause whether environmental/genetic or a mix of the two. This it did. The start-point was *not* whether crossbreeds or purebreds were healthier - although it did find both breed differences and purebred/crossbred differences, which it reported on.

      The whole problem here was not the papers but the stupid interpretation of them by the dog lobby.

  8. I would to see people just being able to get more information about acquiring *any* type of dog. My sister went on and on about how rescuing a dog is sooo much better than buying for a breeder. I heard how rescues were "healthier" and didn't have the hip problems pedigreed dogs have. Within 8 months of rescuing the puppy she had to put $3,000 into "new hips" for the dog due to extreme dysplasia. He died at 8 from cancer. Another friend rescued a dog and had to pay $2k for surgery to re-route the urethra due to crystal formation in his urine. The dog was 2. My golden retriever lived until he was 15, no cancer or heart disease (or anything else for that matter), my Gordon Setter, 12 and my English Setter 13. The worst medical condition any of them had was my Gordon having diabetes later in life. Otherwise, they were all very healthy dogs with few vet visits except for vaccines. Now, that's not to say pedigreed dogs don't have issues, clearly they do. But with sites like this one, you can see what they are, if you take the time to look. Caveat Emptor and all. No one warns people that rescues can be just as or more expensive than pedigreed dogs. I get jeered for "buying" a dog, but more times than not, the people that rescued a dog ended up with one with ongoing or critical health or temperament issues. I'd love to see some balance on the issue. Not every rescue has "hybrid vigor" and not every pedigreed dog is woefully ill. I think this article from the Telegraph falls short on many counts.

    1. Again, not all rescues are the same. There is a world of difference between a pug x Chihuahua mix, and a dog that has husky, shepherd, and retriever in it. Assuming the environment is healthy, then the former would be nearly as likely as those two parent breeds to have their problems (troubles breathing and whelping, getting eaten by a fox, etc). In contrast, the latter dog with at least three parent breeds in it is going to be far more robust.

      I am pleased that your purebred dogs have been overall healthy. However, bear in mind that goldens are more likely to develop bone cancer. A nice mix with some other sporting dogs (lab, setter, etc) could go a long way toward reducing those odds. But breeders don't do that anymore. That was in the development stage, and now their studbooks and gene pool are closed. Now they just "breed away" from diseases. Well and good, but they're only delaying the inevitable inbreeding depression that comes from isolating a population.

      My point is, mixing is a normal part of any species' reproduction. Artificially eliminating that is a recipe for disaster. And with some breeds (e.g. toy and nonsporting dogs), a couple of crosses are not going to be enough. It's going to take generations of back-breeding to return to healthy body shapes and levels of genetic diversity.

    2. Rescues can be a pure, cross or mixed parentage. Comparing in this article is between pure and cross breeding not rescue dogs, although the headline goes for the derogatory term mongrels to draw you in, under that it then refers to comparing pure to cross breeds.
      Hybrid vigor is a number game and is just that two living things crossed that are not closely related are in most cases less likely to carry the same genetic disorders and the offspring have more genetic variation which can improve the immune system, does not mean that they won't have a genetic disorder, but are less likely to.

  9. What were the proportions of breeds and crossbred dogs in the random sample? Did they select to eliminate bias? Also, when referring to skin mass and percentages of crossbred and pedigree dogs, what were the actual absolute numbers? Percentages can be very misleading. Also, prevalence means the number of dogs within a particular population who will have the disease at any time. This study is a good start but it is biased against looking at the real issue which Jemima eloquently refers to.

  10. Purebreed vs. X-breed is a false dichotomy. I work with Labradors (interestingly, represented in the cover photo). Labs are the most common purebred dog in English speaking countries, and very common in many other non-English speaking countries. Statistical studies show the rates of inbreeding in Labs is very low, life expectancy and incidence of health problems is not exceptional for dog size. Historical reports indicate there has been a lot of unreported cross breeding, particularly in competitive sport lines (eg., adding sight or scent hound lines to improve time trials, see Mary Roslin Williams writings and vidoes online).
    Finding an unrelated, healthy stud dog - even one with working or show titles - is easy for a Lab breeder. It is a much more difficult endeavor for breeds, like the Cavvie or like the Wycliffe standard poodles , that descend from a very limited base.
    Unfortunately, the problems are often quite breed specific, and the path forward has to recognize the genetics and particular health problems of individual breeds.

    btw. ear infections are common in most flop-eared breeds, particularly if they swim. Treatments are often extremely simple. The occasional vinegar douche will clear yeast infections. All health problems are not equal. I would much rather see attention given to chronic skin infections/allergies than to ear problems.

    1. Good comment. I think you are basically demonstrating, though, that mixing has helped the lab. Those lines that are inbred are worse of for it, and those that have outcrossed are better off for it. Because labs are so popular, there are lots of lab mixes out there, and those dogs are quite healthy. Pedigreed labs have a whole host of predictable problems.

      BTW - Bear in mind, the lab (like many other related breeds) comes from the landrace St. John's water dog. What often happens is that breeders find some cool landrace out there, whether it's the St. John's in Canada, or the Nenets herding laika in Siberia, or the Africanis in southern Africa, and then get obsessed with turning them into some specific breed with conformation rules. They take a few representative dogs from that landrace, and breed them in that way. This inevitably shrinks the gene pool, and reduces the fitness of the very dogs those people found to be so cool.

      That's how the St. John's was turned into the lab, curly-coated, flat-coated, golden, Chesapeake, and duck-tolling retrievers, as well as the Newfie. If you combine all those breeds, you get back to the St. John's water dog.

      Likewise, the Samoyed was developed from the Nenets herding laika, and the basenji was developed from the Africanis. In both cases, while the parent primitive dogs are incredibly robust, the formal breeds are now predisposed to new health problems due to reduced genetic diversity.

      Breeders must maintain both normal morphology and high genetic diversity, or else they will ruin the very creatures they love.

    2. I agree. Mixing has strengthened the Labrador.
      The point is that genetic health is easier for a numerically large, diverse breed with a broad base. In hindsight, it is unfortunate that the long-coated St. Johns dog group was split into flatties and goldies . . . both breeds would probably be healthier if that hadn't happened. The splitting of the Belgian shepherds is a worry, as are the multiple registries for Border collies.

    3. Yep, agreed again. Splitting up the Belgian shepherd into the various malinois, lakenois, tervuren, etc. is just as disconcerting. Let them just be Belgian shepherds of various types, not uniform breeds of reduced diversity. I was not aware of a similar trend in the border collie. Not good.

    4. It's neither constructive or meaningful to be stuck in the rut of 'cross-bred dog healthier than breed dog, hybrid vigour blah blah'. For a start, in order for hybrid vigour to occur, the parent strains have to be highly inbred. By saying 'breeds are unhealthy, buy a dog that's a first generation cross between two breeds' you are in effect making an irresponsible statement that breeds being inbred and dogs of those breeds' welfare being compromised is fine by you, so long as they continue to exist in this health-compromised inbred state in order to furnish you with your presumed-to-be-healthy cross-breed dogs. It's surely far better for all dogs involved to try to maintain healthy breed populations in the long term than rely on what's in effect a short-term throwaway solution that only lasts for the lifetime of that first generation. And hybrid vigour doesn't necessarily mean an animal is free of conformation problems and associated health risks -- Temple Grandin has written about the state of cross-bred broiler chicken strains and how they have been bred to gain weight so quickly it puts great stress on their anatomies.

    5. Anon 00:45

      Your argument is flawed. You can't continue to in-breed forever. You have to outcross to maintain genetic diversity. Continuing to inbreed guarantees inbreeding depression and the resulting disease burden which is completely unnecessary if people looked at the science. I think you are being too literal about hybrid vigour and are failing to look at the bigger picture. Temple Grandin is not implying that cross breeding is bad. Any sort of breeding program can be unethical - cross breeding or pedigree - if not considered with the health and welfare of the animal at the forefront.

    6. The terms "hybrid" and "hybrid vigor" are commonly misunderstood.

      First, "hybrid" literally means "half-bred." Originally, it was used to describe crossing between two different but closely related species, e.g. horses with donkeys, cattle with bison, wolves with coyotes, lions with tigers, etc. Today, "hybrid" can technically refer to any mixing (even the mixing of DNA molecules themselves), but the original meaning still prevails: interspecific mixing. This is, by definition, is mostly a bad thing because - without going into a tangent about genetics - interspecific hybrids usually have reduced fertility. That is, either they lack the full fertility of offspring within a species, or they may even be fully sterile altogether. Also, depending on how closely related the two parent species are, the hybrid offspring might even have reduced viability, i.e. they might not survive gestation, or if they do, they die as babies. Hybrids between African and Asian elephants, for example, do not last long.

      So, if interspecific hybrids have all these problems, how can they have "hybrid vigor"? Well, the vigor originally meant that, despite loss of fertility, if the two parent species were closely related enough, then their hybrid offspring were stronger than either parent. Mules are the classic example. Although usually sterile, they have a blending of traits from horses and donkeys, and are themselves very healthy. The "vigor" ends in one generation, because mules do not reproduce.

      Fast forward a few decades, and the term "hybrid vigor" refers to something slightly different: the prevention of inbreeding depression by mixing within a given species. In that case, hybrid (i.e. mixed) offspring are healthier because their genetic deck has been shuffled, and their genetically-based health problems diminish. If they continue to mix, they continue to remain healthy. However, if they then begin to inbreed again, the vigor goes away.

      This is what mutts and other crossbred animals are all about. All animals are carrying some faulty gene(s) somewhere in their genome, but mixing helps prevent them from becoming expressed as disorders. Inbreeding simply means that the deck gets stacked, and recessive alleles start to yield health problems. This is as true in dogs as it is in people or any other creature. Selection can help mitigate this problem, but it does not completely resolve it. If you do not allow animals to mix, then you are giving their bad genes a greater chance to become expressed. The more of these bad genes there are, the more inbred the animals become.

      That's why this whole debate has a foregone conclusion. All else being equal (i.e. environment, husbandry, body shape, etc.), the less mixed animal has a greater chance of showing genetic problem than the more mixed animal. Dogs that have been highly altered (e.g. pugs, bulldogs, Chihuahuas, etc.) are really just showing the effects of inbreeding depression. Their extreme bodies are not just "traits"; they are disorders. Other physiological problems can show up in moderate-looking dogs, too, if they are inbred. Extreme-looking dogs are necessarily inbred, so they are likely to have other problems beyond what they altered bodies cause.

      Again, you can't just reverse extreme inbreeding depression in one generation. To save such a line (if you choose to do so), you would have to cross them with other lines many times to get back to a genome with fewer bad genes, and healthier anatomy and physiology. This study totally ignores that.

    7. Probably being stupid but I'm wondering if I'm understanding your explanation correctly. What sort of percentage within a breed would count as inbreeding depression? And what about dogs within a breed that have a very low inbreeding score (say a pug with an inbreeding coefficient of 1% when the breed average is 5.7%)?

      I've always managed to muddle myself with the array of terms in genetics. Is the inbreeding coefficient not relevant to the state of the dog or breed?

    8. Coefficient of inbreeding is a measure of the probability that the organism is homozygous at any one gene locus. The higher the number, the higher the probability.

      COI does not measure inbreeding depression. Inbreeding depression generally refers to an overall loss of vigor or hardiness; in the laboratory, typical measures are fertility, fecundity, and neonatal survival. Poor immune function is often an indicator of inbreeding depression.

  11. Am I missing something? Was this is a serious research undertaking? Because a high percentage of the conditions shown above are caused by bad animal husbandry, how can they be inherited disorders? I understand that ear infections could be attributed to bad breeding because of say excessive ear length, or over wrinkly etc. But those are mostly breed desirable i.e.long ears basset, excessive wrinkles, thick skin in shar pei etc. But as a general condition sore ears are caused by lack of attention by the owner. No mention of entropian, epilepsy, bloat, patellas, hip dysplasia,etc are not mentioned at all. Because they most definitely can be attributed to inbreeding i.e. pedigree dogs and probably per head of population per breed there is a high incidence. They do occur in crossbreeds and mongrels but I suspect rarely. If the true health conditions, inherited ones, are not shown at all, which is why this blog is established, pedigree dogs exposed, then what is the above research about? The graph doesn't appear to show what the percentages are against pedigree/cross breed, or have I missed it? So what is the point of it, what does it prove, apart from a lot of people have collated a lot of information about a lot of health conditions in dogs. Nobody should be making any statements about the status of the health in either pedigree dogs or crossbreeds, because the information doesn't say anything, it is just a statement about health problems in dogs?

    1. The research done was into the most common reasons for a dog to end up at the vet. Naturally, the research showed that the most common problems, whether or not a dog is purebred, are influenced by environment and lifestyle, not genetics. This simple statement was used by the Kennel Club to say that purebreds are just as healthy as mixed breeds- completely ignoring that some breeds have absurdly high rates of epilepsy, heart disease, etc. specifically because of breeding practices promoted by the Club. Basically, they lied by misrepresenting the study and what it was about.

    2. Yes and people believed it because most people:

      a) have no clue how to interpret data and need someone to do it for them and;

      b) do not understand genetics and so couldn't have figured out that the reasearch isn't controlled for genetic disorders anyway.

      Don't be too surprised, it's not the first time a newspaper has headlined something and cited a paper that does not uphold the newspaper's claim (often actually in direct opposition to what was claimed), and it won't be the last.

  12. The Belgian shepherds is one breed and a short hair tevuren is often registered as malinois. There are also several unregistered mixbreed malinois who serve as police dogs and millitary dogs.Just as the St Johans were splitted the St Bernard were divided into 5 dog breeds Entlebucher Mountain Dog, Appenzeller, Bernese Mountain Dog, Greater Swiss Mountain Dog and the St Bernard.

    1. As I understand it, this varies by country: in some places they are considered separate breeds, in others, one breed. But even where they are considered one breed, there isn't a lot of crossing between sub-breeds. Point being, wrong direction to go. More mixing is better. The Saint being divided into separate breeds = another mistake. We need fewer breeds with larger and more diverse breeding populations.

    2. Yes, the splitting up of Swiss mountaindogs / sennenhunds is another example of this obsession with making dogs uniform, at the expense of their genetic diversity. Bad move.

  13. I would rather have a study of SERIOUS health issues comparing purebreds and half-breds, like pure CKCS vs 1/2 CKCS/ 1/2 WSS or 1/2 Papillion. Pugs vs Puggles. English Bulldogs vs English Bull-Beagles (Bugles?).

  14. Personally, I think diet plays a big role in dog health, whether pedigree or crossbreed.
    Im a raw feeder, so obviously am biased, but even if one DOES feed kibble, for gods sake please feed a decent one. I see people daily loading bakers and low grade crappy supermarket kibble into their trolly, and that stuff is just.......its horrific. I can't imagine caring so little about my dog's diet that I'd feed him the cheapest junk full of filler and E numbers. Everyone knows diet makes a HUGE difference to the health of all species.

    Low grade animal protein sources are linked with increases in cancer.
    There is a certain brand of rat kibble sold in the UK which uses the same low grade meat product as you find in cheap kibbles, ie, chicken meal/'meat and animal derivatives', and the rate of mammary lumps and cancer you'll see in your rats if you feed it for a while is genuinely shocking. A 100% increase for a friend of mine, and up near that for most others, across the board. Since rats fit all their life into 2-3 short years, you see results of a crap diet much sooner. Think what these junky ingredients are doing to dogs, even if it takes a few years to show.

    So you have to wonder how much of this is diet related, and nothing to do with breed at all. Did they ask the participants what they fed? Because I definitely would have done. Obviously a dog fed a proper raw diet will trump a dog fed tesco own brand kibble when it comes to health.
    One of the things raw is best for is teeth and skin conditions, two of the most common medical issues in dogs. Many report skin conditions completely clearing up once the raw diet is taken up, and raw fed dogs tend to have far less issues with dirty teeth. My boy just had his yearly check at the vet, and the vet said he had the whitest teeth he'd ever seen, and the vast majority of dogs he sees have some plaque build up by his age (2.5). To me, thats shocking. Dogs shouldn't routinely be having teeth pulled or going under anaesthetic for teeth cleaning at 2 and a half!
    Im not saying everyone should feed raw, I understand its not for everyone, but Im completely sold on the health benefits of a good diet.

    Im not going to comment on which is healthier, crosses or purebred, its not a black and white issue as far as Im concerned and I've known horrendously unhealthy examples of BOTH; husbandry plays a part too. What I see affecting dog health more than breed alone is often diet.

    1. Ideally, we should be breeding dogs with good enough immune systems that they can survive crappy kibble. They were, of course, domesticated as opportunistic scavengers. Please don't misunderstand me...I feed my dogs a better quality and more nutritious diet probably than I eat myself, but you can't blame this stuff on cheap kibble.

    2. I tried my dog on raw. She was ill!

      She gets a very high grade kibble and wet food. And is as fit as a fiddle. Only vet visits are for vaccinations in the last 4 years (another contentious area for health issues - but mandatory for her as she does get boarded occasionally).

      She's also a mixed breed (at least 4 different breeds that we know of according to her DNA analysis).

      The issues are multifactorial - genetic and environmental. Feeding raw diets to a Bulldog with BOAS or a Cav with syringomyelia isn't going to improve their health is it? However, dogs did evolve on the rubbish tip and are scavengers who can digest pretty much everything, including starch. They naturally evolved to have a robust digestive system.

      We really can't underestimate the importance of genetic health here in setting dogs up to have healthy immune systems. I'm not advocating that we allow dogs to breed randomly ( as no doubt the extremists on here will latch on to immediately), but let us not forget that mammals sniff out thier mates based on pheromones to enable MHC compatibility within the immune system....our dogs are severely compromised in that regard. Not only do they mostly not get the opportunity to sniff out a healthy mate, few are allowed to breed anyway and the ones that do get to breed are selected for reasons entirely at odds with health and temperament at the forefront. Don't blame a bad diet for the current state of the dog.

    3. If my parents obese and huge Newfoundland mix can live to 13 on the cheapest kibble possible and junk food I think their is more going on than just food. I've also known of other dogs feed garbage live very long lives. Even the dog I have now who is a breed known for health issues is now 6 years old,only feed medium quality food because that is all I can afford and is as healthy as they come. It frankly only adds to a small extent,and obesity and other forms of toxicity is also a problem with pet dogs. If you breed healthy dogs with good immune systems,than food will make little difference.

    4. My friend's lab/mastiff cross died at six having been the cheapest kibble possible. This is an example of anecdotal evidence being misleading.

    5. Also, dogs may have evolved as scavengers but they weren't scavenging cheese burgers and crisps. They'd have scavenged mainly raw/cooked meat scraps and various vegetables, all of which would have been organic. Processed dog food is a 20th century invention, Neanderthals didn't say "whoops, we're out of Bakers Complete, better pop to Asda."

      And diet CAN help animals with health problems, including cavs with SM or dogs with hip dysplasia. Certain foods and additives exacerbate inflammatory markers, others reduce them, diet can have a huge impact on inflammation. And of course IBS/IBD, breathing disorders, allergies, coat condition, even parasite control. Poor diets may not be the only problems dogs have but it doesn't help.

    6. Diet is not the root cause of poor immune function in dogs - it's caused by inbreeding depression. I think your friend's dog dieing aged six is also a case of anecdotal evidence being misleading. Is there evidence that his death was a direct result if eating cheap kibble?

    7. Excellent point Ziggy, it's over looked by many pet owner who think just because it has a picture of an animal that looks like their pet on the front, that it is an ideal balanced feed.

    8. My dog cannot handle raw food, it made him violently sick with blood in his stools for a few days.

      I feed him gently cooked food with calcium supplementation. He gets a mixture of meat, greens and a small amount of grain in winter.

      When I do not have time to cook for him he gets a high grade kibble but I never feed this too many days in a row as its basically like eating coco pops all the time (fortified vitamins etc). Not good for the system.

  15. I favor the idea of making a breed called "Bird Dogs" where activities, like hunting, divide Bird Dogs into sub-levels of Pointing Dogs, Retrieving Dogs, Flushing Dogs, Dual Purpose Bird Dogs, and Exotic Bird Dogs, while shows continue to exhibit the bird dogs as they now do (by breed) - except each breed would be a variety of the one breed named "Bird Dogs". The difference in shows would be that if you had a 7/8 Flat-coated Retriever 1/8 Golden Retriever, you could enter him as any Bird Dog variety, whether it be as a Flat or Golden Retriever.

    I would like for the herding, watch dog, terrier, lap dog, etc types to be breeds with sub-divisions too.

  16. Ziggy that is a very valid point. My dogs when fed maize which was in the brand of dog food I used years ago broke out in eczema because it was overheating and indegistible, so from experience, I would definitely agree. Anon 2005, and I am sure that this will happen because as the breeds fall away there will be a need to cross breed. The trouble is that say, the setter breeds, are so compromised health wise that even if cross bred the hip dysplasia, entropian, etc will just follow on, the dog will in essence be a bird dog, of no specific title, but just as "sick". I think that the people who breed working types would be very reluctant to have their stock contaminated with show stock because of the inherited disease factor. They breed their dogs for function, not for exaggerated breed type. Their dogs look like irish, English, Gordon, red and white setters, but would be thrown out of the show ring because they are just not refined enough. Though if one looks at setters working, their style and deportment is astonishingly beautiful and as that is what they were bred to do then, now for me, that is the correct type. But as you say, it will come down to dogs bred to do the job, lumped together, eventually because there is nowhere else to go. I suspect that some mongrels will be brought in too, just to try and widen the genetic pool, but even that scenario has a limited shelf life. It is fascinating nonetheless.

  17. The next study should be...

    'How does the incidence of [the top 5 conditions which cause death or significant disability/discomfort] vary between Pugs, Beagles and Pug X Beagles, and between Cavaliers, Miniature Poodles and Cavalier x Miniature Poodles, and between Labradors, Standard Poodles and Labrador x Standard Poodles, (etc)?'

    Easy. So...

    1. Study only those conditions which affect dogs' lives most negatively, because they are what we care about, and

    2. Compare their incidence and severity in the two purebreds being crossed, and in the resulting crosses.


    1. I agree that the study reported on trivial health problems and more focus is needed on serious conditions. However, that's anything but easy.

      Problem #1: If I designed such a study I could load the dice in favor of the outcome I was looking for by choosing healthy or unhealthy lines of the breeds involved.
      Problem #2: There are hundreds of combinations worth of study, and half a million possible breed combinations (assuming 225 breeds).
      Problem #3: Many of the serious dog health problems don't show often show up before age 5 and often wait until 8+ yr to show up. Sample sizes of 30+ dogs for each case are required for statistical significance. Hey! This experiment is going to cost multi-millions.

    2. Absolutely right Jennifer, and at the end of day, if breeders could be persuaded to stop breeding for such exaggeration, slowed down the breeding and were more intelligent in their approach, the milions that it would cost to do such an experiment/survey would be well spent on the dogs that are suffering as a result of the bad breeding and the millions, world wide, rescue dogs it would so much more worthwhile. Stats. don't you just love 'em. in reality a load of tosh.

    3. We are not naturally attuned to understand statistics. Statistics arose in the mid 17th century and we have evolved o understand the world in a different way. We are more naturally attuned to understanding natural frequencies as opposed to conditional probabilities. Gerd Gigerenzer's work confirms this. There are staggering numbers of doctors who don't understand the difference between sensitivity and specificity of diagnostic tests, how to convert percentages into actual prevalences and also fail to grasp the significance of prevalence when applying this. Journalists and politicians also frequently misinterpret this sort of data too. Hence the Telegraph article in this instance completely misleads.

    4. Having taught stats . . . humans are pattern seekers (we imagine all sorts of weird and wonderful things looking at clouds or constellations of stars) and have a hard time coming to grips with randomness. It takes a combination of critical thinking skills, honesty, and statistical training to effectively work data. Without that combination, however, we're open to biased interpretation of events.

    5. So why do scientists continue to publish papars that few people can interpret clearly and with the appropriate rigour? They then leave it up to the journalists who are equally as clueless, such as The Telegraph and the Dog lobby (who are on the whole, clueless too, judging by the reaction to this) who latch on and twist it to their own agenda.

      If it takes an appropriate skill set to make sure that people are receiving and understanding the correct information then we have another issue here...

    6. Scientists publish papers for other scientists. If they had to explain probability and statistics, etc., every time they wrote a paper that used them, papers would get incredibly long, there would be huge amounts of redundancy, and the whole peer-to-peer communication system would fall apart. Plus, many scientists aren't super good at writing, especially writing for a popular audience. You may disagree with the attitude, "it's not my job to communicate it to the public" but you're going to have a hard time hard time changing it. It is deeply engrained in the system.

    7. Indeed! It's a problem that really needs to be addressed at a grass root level. Often a lot of people whom we think understand these papers (scientists and medics included) don't! What chance does John and Jane Doe have then?

    8. All scientists will understand this. It's not a difficult or specialised study. Trust me I've read far worse.

      Many intelligent lay people will understand it too, you just need logic and a basic understanding of how an experiment or scientific study is conducted (which you should have learnt in school - at GCSE level).

      I don't understand the attitude "why do scientists publish something only other scientists will understand". Of course they do, it's not meant to be for the public to understand, it's meant to give information to regulatory bodies, vets, other scientists, specialists in government etc.

      The media just picks up the paper and the ignorant journalists read what they will into it since most people working in media have 0 understanding of science / nature / technology / maths... Basically anything except media.

      If you as a lay person, want to better understand how to interpret data, just do a little reading of some A level biology / physics books on experiments and how to write up the results. Lean what "controls" mean, and what a null hypothesis is, and then look up statistics and significance. If you want to go wild, have a look at "margin of error". Then you will be able to ignore what the journalists say and make informed judgements yourself.

    9. Anon 14.42 your arrogance is hilarious and really unhelpful.

      I would say if that there are any lay people out there who don't understand statistics or can critically evaluate scientific papers, don't worry! Science isn't conducted in a user friendly way and most people won't find what the answer to this in an A level science book.

  18. Having looked at the study results -- as opposed to the reporting of them -- I find myself shrugging my shoulders. The confidence intervals on crossbreed dogs are huge (surprise, surprise . . . . there is immense variation among crossbreeds). Due to the statistical scatter in cross breeds, most of the statistical tests used failed to show any statistical significance (p = 1.000, meaning it's entirely likely that the result could have gone either way depending on luck of the draw . . . differences are not statistically significant).
    It also looks like the 'findings' are dominated by a high incidence of vet visits by geriatric, obese Labradors with fatty lumps. . . also Staffies with skin problems.
    It would be interesting to have some critical thinkers with a good knowledge of statistics rework the raw data.

  19. The second study quoted is no more illuminating than the first. Asides from actually refuting the hypothesis that breed dogs are never on average as long-lived as mutts, since three of them were demonstrated to be on average longer lived, there is too much variability in the categories. There is no taking into account how the breeds differed from each other with it lumped together as 'breeds' vs. 'cross-breeds'. Some breeds are incredibly unhealthy. Others fare much better. There is also the factor that larger dogs do not live as long as smaller ones, for the same reason that very tall or heavy people do not on average live as long as smaller ones. It must also be taken into account what might be the average genetic makeup of mix-breed dogs. In the case of mix-breed dogs born unintentionally, there is an element of natural selection that must do something to prevent the unhealthiest of breeds making genetic contributions to this category. Breeds that are so distorted they struggle to mate naturally, or escape and move about easily, are unlikely to be significant contributors. Most mix-breed dogs seem to derive their ancestry from small and medium-sized, popular breeds capable of getting out of a back garden and navigating to another property, and the perennially popular breeds do generally have a bit of an advantage with gene pools in the first place. It also does not take into account that mongrels are not immune from inbreeding, either deliberately or by accident through random matings or deliberate breeders experimenting with dogs they don't have sufficient information on the lineage of. It would make far more sense for people involved with individual breeds to concentrate on the specific problems within that breed and what can be done to improve them, rather than getting fixated on this argument.

    1. Oh, you mean the breed clubs?

      I don't think we can trust a lot of the breed clubs to ask the right questions. They are biased and not in favour of the breed's health.

      We would do better to perform a psychiatric evaluation/study on the people who run them. They have an ideology to uphold the breed standard. Science threatens their very existance. Reminds me of Scientology a bit....cults etc. Scary stuff.

    2. Most mix breeds and mongrels are medium sized for a reason: that is the natural "wild type" size of the domestic dog. When wolves were domesticated one of the first changes was to shrink in size.

      When you breed randomly you get closer and closer to wild type. In dogs, this is roughly border collie sized, solid coloured light brown, reddish, or tan, short to medium coated and roughly dingo shaped (close to working BC or kelpie shape).

      Personally I find the wild type dog the most beautiful, better than ANY breed (other than a wild wolf of course). I think functionality is beautiful though - most people seem to be impressed by shiny things and extremes.

  20. the problem here is rather a definition of the ailments in question. Outgrown claws and underexercised can scew results as much as lack of health self care in humans. such don't really tell much about canine breed health.

  21. What good are breeds with healthier genetics if poor animal husbandry is still making them sick?

    The researchers set out to find the most prevalent causes of vet visits (what is most likely making dogs sick). What they found was the most common illnesses in dogs are not genetically linked; therefore, making our breeds healthier will not improve the health of our dogs until we have improved animal husbandry. In some respects the dog lobby is correct, they are not the leading cause of illnesses in dogs; owners are. However, this study does not absolve them from their responsibility in the poor genetic health of our dogs.

    So, are the posters in this blog interested in healthier dogs, or only interested in genetically healthier dogs? Based upon how many have berated the study one might think they are only interested in genetically healthier dogs.

    1. I think given that this blog is dedicated to the remit it describes, the primary concern is educating the people who breed dogs to focus on breeding for genetic health and to use science to help them do that effectively. You can't take on everything at once.....Jemima's been very clear about the purpose of this blog.

      That doesn't mean to say that people who read this blog are not concerned about the general health of the dog population per se. They're just focused on the issues as to why the blog exists in the first place.

    2. Many purebreds life span and general health is going down at a rapid rate despite husbandry practices improving. It is kind of disturbing to think that dogs that where fed primarily on grains,no vaccinations and lived outside 24-7 where doing better than the dogs feed on high quality food and coddled. With good breeding dogs should live decently long lives even with bad husbandry sense it really only makes a small difference.

      Plus part of it has to do more with classism,not all people can afford high quality food or even have butchers in town. While it costs more to get a dog like a English bulldog than some other popular breeds and of course just going to a shelter.

      Plus some of it is just based on the need for more education,like what is poisonous for dogs and to encourage people to control their dogs better. Some things like torn dew claws,sprains,broken toes,bites and lacerations can happen with any dog that is active and playful and would be a silly thing to focus on. If a dog never gets those types of injuries than perhaps the dog was not even sound to begin with,sense you want a dog to be athletic and take risks.


    Yet again, The Telegraph manage to completely twist it and unnecessarily worry dog owners! Feeding your dog scraps of vegetables, meat and pasta as part of their daily food ration isn't going to kill them though is it!?

  23. On further thought, this article tries to address the problem that arises from the lack of good prevalence data. Ie, to talk about breed health, it would be extremely helpful to be able to say what percent of the population of different breeds suffered from various conditions.
    The methodology, unfortunately, doesn't really get at prevalence. The data it works from is prevalence of a condition IN THE DOGS THAT ARE TAKEN TO THE VET. It's not entirely clear what this means. Eg, if 7% of the dogs coming to the vet reported obesity, does this mean 7% were obese, or some much larger fraction was obese, but 7% of owners came in looking for help with weight control; or perhaps 7% came in with some condition and the vet prescribed weight control as part of the program to manage the condition.
    The high incidence of ear infections and nail clipping also raises sampling and definitional problems. If I have a dog that requires regular cutting of coat, eg., a poodle, I am most likely to have the groomer do the nails at the same time as the coat. I may also get advice from the groomer on various other common problems, such as ear infections, diet, etc. So dogs whose owners rely on groomers are in different treatment regimes than those who just see vets, and the incidences reported by vets don't reflect the true population incidence.
    In addition, there are dogs whose owners avoid veterinary care altogether, whose data simply don't show up in the data.

    Bottom line: Nice try, but the results are extremely hard to interpret. Prevalence in a dog population, unfortunately, is not equal to prevalence as reported by veterinarians.

    1. These issues are no different than any other epidemiological study or survey data. You only have the data that was collected; drawing conclusions on the causes of observed trends is not possible.

    2. Wrong. Epidemiological data can be very useful in narrowing the suspects for cause, especially if it is used to look at one suspected condition that is almost guaranteed to cause a reportable event such as hospital admission or death. Better information might have been cleaned from this data, for example, by looking at some sort of cluster/pattern recognition analysis that allowed multi-factoral associations (PCA or related methods) to show up. I suspect clusters in the data from the charts presented, eg., small terriers have different maladies than Labradors.
      Data are a scarce resource for work on dog health. Thoughtful analysis of data are needed for a dataset such as VetCompass has accumulated. I hope they make the raw data (in anonymous form) available and some gifted, dog-familiar people have a chance to rework it. The analysis in this article is humdrum and the results are not illuminating.

    3. Epidemiological data show correlation only it does not demonstrate cause and effect. The observed trend may or may not be caused by one of the other factors measured. As you say, the data can point to possible causes which must be tested/proven with a controlled study. Drawing conclusions on causes cannot be does with these data; developing hypotheses (to be tested) can be done with these data.

    4. The general public and the popular press frequently draw incorrect conclusions ("the study showed x was caused by y) from the trends in epidemiological studies.

    5. The other problem I have found with data collected in surveys at Vet clinics is the breed identification is not always reliable. Several publications I investigated for our breed revealed that published low incidence rates of diseases were likely skewed by incorrect identification of mixed breed dogs as a particular breed based solely upon appearance (as reported to me by authors of the studies). In one case a researcher with the study personally followed up with the owners and confirmed their dog was incorrectly assigned as a particular breed.

    6. PipedreamFarm, that's right about misidentified breeds. One of my colleagues bought a sandy-red coloured German Spitz thinking it was a Pomeranian from the picture and he didn't realise how much bigger it was until it grew up. He paid several thousand for a dog and still managed to get the wrong one.

    This death of a pug wouldn't come under any of the illnesses referred to in the research. It's enough to cause P&O to review its policy on brachycephalic breeds though. Maybe we all should review our attitude so that these dogs do not suffer. Bring back their noses!

    1. Have you read the paper? The death of a pug would definitely fall under the category "death". It would probably fit under "respiratory" as well. If I had access to appropriate software and the raw data from VetCompass, plus a few months to update my computer skills (I've been retired for a decade) I'm pretty certain I could come up with some strong statements on health concerns in brachy breeds.

    2. Jennifer - I wish you could get access to the data. You are a voice of reason on here....and you have the skills and knowledge to back it up. Do you not fancy a nice little retirement project?? Write to Vetcompass?

    3. Something we can all do for pugs is to refuse to buy them.

      Don't buy them and tell your friends and family not to buy them.

      If you know someone who is thinking of getting one put them off, tell them why they suffer their whole lives.

      When people stop paying the breeders for their little abominations, the breeders will have to change the breed to make it acceptable.

      Until we hit them where it really hurts (their bank account) nothing will change.

  25. I guess that veterinarians can be just as blind to what is right in front of them as dog breeders and dog show judges can be.

    In a show ring, judges can over-focus on how big a Brachycephalic dog's head is and how breed typical the dog's tail is, but not notice that the dog's skin hangs in folds and the skin is infected.

    A judge can, at the same time, judge the minute fineness of the shape of a Collie's muzzle, yet fail to notice that the Collie is blind. A judge can focus on the cuteness of a Pug's expression, but completely fail to notice that the Pug isn't breathing right.

    In choosing to focus on the most common reasons for a dog to be at a veterinarian's office, but overlooking the need to see the severity of the illness, an error of omission was made.

    Common sense will tell you that overgrown toenails are NOT due to genetics. Many of the problems, like clean ears and gums, are mostly grooming problems (although allergies can make for skin and ear troubles) while problems like anal glands have a diet and exercise component as well.

    And lacerations and other injuries like that can happen to any dog.

    Nothing in these stats pertain to the question of health problems in purebreds vs hybrids. The show breed standards obviously call FOR many health problems, and inbreeding has fixed several other serious health problems in purebreds - like High Uric Acid in Dalmatians.

    It seems like nothing but a red herring paper.

    1. Indeed. When I saw the list of conditions I laughed. None (or almost none) have a genetic component at all. What is the point of comparing PUREBRED to MONGREL if you aren't comparing on a genetic basis? Genetics is all that separates them. Aside from one being selectively bred and the other being randomly bred there's no difference.

      Unless you are trying to compare the level of care the dogs receive from their owners - why would you do this, it tells nothing about the healthiness of pure vs mutt?

      I don't understand the point of the study at all unless it was to try to make the results come out in favour of purebreds (on the assumption that purebred owners will spend more money and time on their dogs).

      Why are they wasting money on such ridiculous "research" when they could be looking at something useful?

      Next time do a study comparing genetic disorders in purebred vs mongrel please.

      Oh wait... We already have several of those.

  26. This death was caused by respiratory failure on the car deck of a ferry. Considered important enough for P and O (quite a big company) to review its carriage of ALL brachycephalic breeds. As these breeds cannot fly already this potentially could curtail their movement for showing and restrict owners who want to travel with their pets. I think your response to my comment helps to highlight that a death such as this is more powerful than its location as potentially one of 65 deaths in that stats. That's not to say that the research is not intriguing interesting and informative in its own right.

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  28. I'm tired of people using ligers as an example of hybrid vigor being false. Hybrid vigor does not mean a literal interspecies hybrid. It is just catchier than "Distant Outcrossing Vigor".