Friday, 25 May 2012

UK crossbreeds live longer than purebreds

Er no... probably not.

Based on the studies already out there, we stated in Pedigree Dogs Exposed that the average mutt lives longer than the average purebred. It caused a furore - and still, today, the dog fora are full of breeders stating categorically that it this a myth. I've discovered that it's pointless to provide a long list of references which show that they are wrong. They simply won't believe it.

But if the preliminary results from VetCompass  - the UK's amazing new veterinary surveillance scheme -  are borne out, it will be much harder for breeders to maintain that purebred dogs on the whole live longer than mutts. Based on death-data for nearly 5,000 UK dogs,  it found that, overall, crossbreeds live "significantly" longer than purebreds with only the Border Collie and Springer Spaniel living longer according to the data (but with the difference so small the researchers say it is not statistically significant). (Download pdf of the poster here)

Overall, the data show that purebreds die 1.22 years younger than crossbreeds.

Here's the figure showing the most popular breeds.


Now there are limitations to this data - most critically, perhaps, that the crossbreed data does not split the dogs into weight categories. This is important because we know that big dogs live less long (on average) than small ones.  Previous studies that have split the dogs on weight have found that size-for-size, crossbreeds still live longer but that 1.22 years  gap could be skewed either way if small or large dogs are over-represented in either the crossbreed or purebred category.

But the weight data is available because VetCompass "mines" its information (anonymously) from an increasing number of UK veterinary practices and they, of course, do record weight. When I broached the issue with Dan O'Neill from VetCompass, he said that the full analysis of the data with this weight-variable included is in progress. 

The study also found that being neutered was associated with increased longevity - although the reasons for this are unknown. (It could be, for instance, that neutered dogs are less likely to be euthanised for behavioural issues rather than that being neutered is protective disease-wise or perhaps owners who neuter their dogs just look after them better.)  And, extremely interestingly, the study found that insured dogs live less long than non-insured dogs.  This sounds kinda counter-intuitive - and wondered if it might be due to increased veterinary intervention having the opposite effect to the one desired. But Vet Compass's Dan O'Neill warns me against confusing association with causality. "Perhaps people insure the dogs that are likely to have problems and don't insure or let lapse those that are healthy," explains Dan. "Or perhaps better welfare standard come from euthanasia  - so shorter relative longevity -  rather than letting animals live to the bitter end which may result in longer longevity but less welfare."

This preliminary data from VetCompass - which has now enrolled over 250,000 small animals in the UK, including over 125,000 dogs - reveals how incredibly powerful this kind of veterinary surveillance is going to be in answering questions about dog health more definitively than has ever been possible before.  

The Kennel Club too, has woken up to its potential and the KC's Charitable Trust has recently committed funding to a study to look at the health of KC registered dogs - as opposed, presumably, to non-KC purebreds and crossbreeds.  The results of that looks set to dispel - or confirm - some long-held beliefs.

In the meantime, just for fun, I've compared the above VetCompass data with the longevity data from the KC's 2004 health survey ("Methods and mortality results of a health survey of purebred dogs in the UK", VJ Adams et al, JSAP 2010) for those breeds for which the data is available (which excludes Jack Russells as they are not a recognised KC breed and German Shepherds on account that they never sent back any survey returns to the KC...). It makes interesting reading. 


Overall, I'm surprised at how closely matched they are because the KC survey relied on breeder/owner reports and, traditionally, self-reporting introduces bias. (Kelly Cassidy found, for instance, that owners often overestimated how old their dogs were when they die - see link here).  Since the vet data is more objective, it looks like the KC survey had limited bias in its responses - or perhaps the bias cancelled itself out.  My concern about the KC survey was always that it might have painted an overly-rosy picture given that the survey forms went out to just breed clubs which might have a vested interest in downplaying health concerns. Conversely, I know many breeders believe that only those who have had dogs with problems are much more likely to complete a health survey.

Nevertheless, there are a few notable differences between the VetCompass and the KC survey data, which would seem to relate to the fact that the VetCompass data comprises the more generalised purebred population. For instance, we see that the KC-registered Border Collie, Springer  and Greyhound all live a year less long than the general population - perhaps reflecting increased longevity in the working dog?  Conversely, the KC-registered Staffie and Cavalier King Charles Spaniel live a whopping two years longer than the general population. I would guess that the Staffie difference might suggest better temperament in the KC-registered dogs, while the CKCS difference could relate to the numbers of puppy-farmed Cavaliers outside of the KC population. 

Fascinating stuff!

85 comments:

  1. Thanks for the info. My golden retriever is now 13 years old, purebred, granddaughter of the famous World Champion Standfast Angus. She's doing good so far. No litters, not spayed, healthy. However, her dad lived 13 years and her mother only 7. I hope that she'll stay longer with us. Still going for long walks every day. Here you can see her photos from this spring:
    http://flic.kr/s/aHsjyuHU1E
    And here is her pedigree:
    http://www.k9data.com/pedigree.asp?ID=116199
    She wasn't a champion so I didn't breed her.

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  2. "But Vet Compass's Dan O'Neill warns me against confusing association with causality"

    and yet you cannot help yourself.

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  3. Thanks for posting. I'm curious. I'm sure the mix breed category contains shelter dogs with unknown dates of birth. Are we artificially aging dogs? If so, there's not that much variance in the median age to prove statistically relevant.

    More interesting I think, is the reason for animal death in the study. How many of those causes could be linked to genetics? A cursory look shows most fall into that category.

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  4. I would very much like to understand the association between neutering and longevity. Especially when other studies suggest that entire dogs are less likely to die of cancer (hemangiosarcoma, osteosarcoma, urinary bladder and prostrate cancers). A study on Rottweilers suggested that entire females live on average 30% longer than their spayed counterparts. Were the study animals separated into males and females - did sex make a difference to longevity? It is possible that neutered males, so long as they don't die of cancer, live longer than entire males. However, my old dog became an old dog overnight after being castrated, so I'm very reluctant to take that risk again.

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    1. Interesting. I wonder what the incidents are of womb cancer in entire females? I have an 8 yr. old entire female and she comes into season approx. every 8 months.

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    2. Rottweilers are a special case. They start with a very high risk of bone cancer and neutering increases it so a good vet will sit down and discuss this with a rottie owner.
      Uterine tumours are uncommon in bitches but pyometra (life threatening womb infection) and mammary tumours are much more common. My recommendation for females is to neuter once their breeding career is over having seen too many with pyometra/mammary tumours. With males the health benefits of neutering are smaller but there can be significant temperament benefits for some dog/owner combinations. The biggest entire dog healh issue is benign prostate enlargement but this is benign and there are now several good, non surgical options for management. My own boys then get to keep theirs, my girl will be spayed if he health tests aren't good enough or after she's done her breeding if they are. With neutering, as with so many other areas, there is not a blanket right or wrong answer.
      VP

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    3. I came across this dog longevity article on Wikipedia: "[A]ccording to a study by the British Veterinary Association (author AR Michell is the president of the Royal College of Veterinary Surgeons), "Neutered females lived longest of dogs dying of all causes, though entire females lived longest of dogs dying of natural causes, with neutered males having the shortest lifespan in each category."

      http://en.wikipedia.org/wiki/Aging_in_dogs#Factors_affecting_life_expectancy

      So, if everybody trained their dog to have excellent bite inhibition as a puppy, there would be fewer serious fights (i.e. blood drawn), amongst entire males and they'd therefore stand a better chance of keeping their furry plums? Castration is not essential for dog population control - a vasectomy would solve that issue.

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  5. Annie Macfarlane25 May 2012 at 19:39

    this is very interesting Jemima...thank you for blogging. It would be great to see an all-encompassing study using data from vets ie the number of crossbreeds and purebred dogs registered with their practice and the number of times a vet has had to treat such animals. That way we could see the dogs that need to have veterinary treatment, giving a more "rounded" snapshot of what's going on. Dogs can live for a long time but live in pain or have a life limiting condition. Longevity is interesting, but hides a lot.

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    1. No. What would be needed is a central database where owners can submit information through their vet for disease processes that must have veterinary intervention.

      "the number of times a vet has had to treat such animals" would be completely useless as data because some people take their dogs to the vet for every little thing and some take care of minor stuff at home.

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    2. Annie Macfarlane26 May 2012 at 11:54

      Jess, do you really think that pet owners are going to submit information? It has to be done at source. If an animal needs veterinary treatment...it needs veterinary treatment. It's up to them to sort out what warrants inclusion in the study data! The professionals need to be the people who make the decisions on that....not joe public or breeders.....it has to be unbiased. Set down the guidelines for submissions and vets will follow them.

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    3. You did not read what I wrote:

      "What would be needed is a central database where owners can submit information *through their vet* for disease processes that must have veterinary intervention."

      Please pay more attention if you plan to take me to task.

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    4. Might as well rule out getting a true picture of the health of brachycephalics since over 50% of owners in a recent study at the RVC thought it was quite normal to have a dog that was actually showing signs of brachycephalic airway syndrome.

      http://www.ingentaconnect.com/content/ufaw/aw/2012/00000021/A00101s1/art00010

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  6. I have emailed the link to my vets and said they have my permission to submit any data about my dogs,

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  7. Caroline Thibodeau25 May 2012 at 22:57

    Perhaps owners and breeders of pedigreed dogs just take their sick and old dogs to the vet more often than the owners of mutts. I`ll bet a lot of mutts, hunting dogs, pack dogs etc. die without benefit of vet care either at the end of a shotgun or just from ill health. These dogs don`t figure into the stats at all. Chances are greater for a mutt to live to an old age if it survives the first couple of years without dying of some inherited illness or being euthanized because of temperament, ill health or just being unwanted. These stats take none of that into consideration.

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    1. Annie Macfarlane26 May 2012 at 12:03

      It's my experience that owners and breeders of pedigree dogs takes their dogs to the vet less frequently than pet owners....simply because they think they can treat stuff themselves. Are you trying to say that if we own mutts then we don't care for them as much as a pedigree dog? That's just beyond ridiculous! I've heard this said so many times and always by people who own and breed pedigree dogs. You have no understanding of how people bond with their dogs - and there are just as many pedigree dogs out there now whose owners won't take them to the vet. Pedigree snobbery is an awful thing to see and hear....dogs are dogs...whether they be pedigree or crossbreed...and I happen to love them because they are dogs....not because they salve my ego! The evidence shows that two of the breeds most likely to be used for work ie border collies and springers live longest....so if we take your theory then they should factor very low on the list.....being that they will be shot by their owners and never visit the vet. Your comments about mutts too are beyond ridiculous. Any dog can end up in rescue....it's the way they are brought up that makes the dog....and....look at the number of staffies in rescue....a pedigree breed and it's estimated that 60% of staffs will die before their 2nd birthday.... You don't see lots of mutts in rescue these days....all the spaces are taken up by the people who have bred staffs without a second thought. My collie cross will be 15 this year....my other dog died when she was 12.5 years old...collie cross. My other pedigree dogs are just as healthy.

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    2. Caroline, While I respect your oppinion a 100% I would like to say that whether owners take their dogs to the vet often enough or not at all perhaps depend more on the type of people the owners are (conscientious or not) rather than what type of dogs they have (purebred or not). I think that when it comes to responsible pet ownership the owners personality is a lot more important than their social or economical background or indeed whether their dogs are pure or mixed breeds.
      And could you please give me an example of inherited diseases that mutts suffer from that is not known (or more prevalent) in pure bred dogs please, cos I can't think of any.

      Gloria

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    3. I never said that there were diseases that mutts suffer from that are not known in pure bred dogs.

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  8. Thanks for posting some early results from VetCompass.

    It'll be interesting to see how the VetCompass data develops, and to see a more complete reporting . . . more breeds covered . . . more discussion of the 'data mining' methods used.

    Any idea why they haven't included breeds with life expectancy below 8 years? I'd think that would be where PDE's attention would focus.

    Will they do further analysis using causes of death?

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  9. But this only refers to dogs that have been reported to a vet, as most dogs die at home having had no recent vet treatment as they are just old dogs, this data by its very nature is scewd. As for mutts living longer its has figures for 3 times as many mutts as it does for any pedigree breed indeed in some cases it has over 12 times as many, based on your logic in these figure does that mean a ShihTzu are 12 time less likely to ever visit a vet than a mutt?

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    1. I am sure some dogs do die at home and the vets are not informed - but surely that would apply equally to purebreds amd mutts? That said, I do think that vets, certainly here in the UK, get to know about most deaths, even if they have not euthanised the dog. Old dogs tend to need treatment as they approach the end.

      As for the longevity difference, the figure was arrived at by comparing all crossbreeds with all the purebreds. If you click on the link to the poster, you'll see there were almot 5,000 dogs in total - the vast majority of them purebreds.

      What is not fair is to lump all crossbreeds together as a breed when comparing to individual breeds such as the Shih-Tzu - and as Dan O'Neill says, the full analysis will take in the weight variable. In other words, you'll be able to compare Shih-Tzus with crossbreeds of a similar weight.

      Jemima

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  10. My grandmother had a rat terrier cross, her name was Talia. She lived to be 18 and a half, such a sweet girl. My grandparents in general had all sorts of dogs. Ranging from purebreds, crosses and mixes - all of which had either long or short lifespans. Talie was the only cross whom lived the longest.
    - Fang.

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  11. And insurance companies providing cover for pets have known for many years that the owners of crossbred dogs on average are in the lowest category for claims for veterinary bills, and therefore place them in the lowest category for premiums, with some "pure" breeds paying up to four times as much. The calculation of premium is based on records of actual claims, and not on a political agenda promoting the ownership of non pedigree dogs

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    1. Any chance you have a link for the insurance company data? I've spent hours with Google looking for it and can't find it. Thanx

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    2. @Jennifer: Probably not really what you're really looking for, but Embrace Pet Insurance (an American company), lists the various health problems for each breed and how much they would cost to fix. Some may not apply to UK dogs, but it gives you an idea. http://www.embracepetinsurance.com/health/breeds/dog-breeds.aspx

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    3. http://www.dogsey.com/dog-breed-insurance.htm

      Comparison of insurance cost by breed, for Jennifer

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  12. And having said that crossbred dogs pay the lowest insurance premiums, I still have no urge to go out and buy one :)) I still prefer my KC registered breed with its recognisable characteristics and working style which derive from 200 years of selective breeding for a specific purpose, and no crossbred (other than a cross with another setter) could give me anything as well suited for that purpose. Its an honourable alternative and a challenge to try to breed a "pure" dog which will (on average) equal or do better than a crossbred for health , fertility and longevity, and the size of the vets bills it generates. I become irritated by people who urge ME to adopt a rescue mixed breed instead of breeding KC registered setters, but IF I only wanted a nice healthy dog with no other purpose than being a family pet, I might well be looking at one of Jemima's retriever cross rescues from an Irish dog pound. At the moment, I will stick with what my setters.

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    1. Don't forget that there are many selectively-bred, non-KC specialists, too - lurchers, sprockers, jack russells...

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    2. Experienced lurcher owners, especially those who work their dogs, like to know what's in the 'mix'. If they know which individual breeds are in the dog's ancestry and to what degree, they will have a good idea as to the temperament of the dog - as good an idea as if the dog was purebred. I, for one, would avoid anything with terrier in - they're the only ones I've come across with iffy temperaments.

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    3. There is a DNA test available on Amazon to determine the various breeds that make-up a cross-breed, so owners can now find out what they're working with. In the past, one of the main reasons why people avoided cross-breeds is because they didn't know what to expect, temperament and trainability-wise. The DNA test can take the guess-work out of this.

      However, unless they vastly come down in price, I doubt rescue centres would be able to afford to DNA test the dogs. This is a shame, because the dogs would stand a better chance of being rehomed if their ancestry was known; the cost of the test could be offset by the dog spending less time at the rescue. I think one of the reasons why designer cross-breeds are so popular (apart from the fancy names), is that people like the thought of hybrid vigour, whilst also having a good idea of the temperament of the dog. Of course, unless both parents are health-tested (and pass!), the puppies still stand a chance of inheriting problems.

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  13. and this is surely because far more pedigree dogs are taken to the vets so are less profitable to insurers -

    "If you click on the link to the poster, you'll see there were almot 5,000 dogs in total - the vast majority of them purebreds."

    just how credible is this kind of data when you're not comaparing like with like ? - has anyone measured the average life span of Papillon or Newfoundland sized mutts against their pedigree counterparts ?

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    1. Bijou, the weight/size issue is addressed above... But, essentially, it is on the way.

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    2. "and this is surely because far more pedigree dogs are taken to the vets so are less profitable to insurers - "

      I wouldn't bet on that. The vast majority of my own vets practice is mixed breeds. I imagine it probably varies by region, income, etc. as well.

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  14. Really interesting data, but it's a shame 'crossbreed' covers everything that isn't a purebreed! Some crossbreeds, such as lurchers and undefined terriers produced by years of careful breeding for function are exceptionally long lived with lots of 15year olds about and many heinz 57's prduced by years of survival of the fittest accidental matings fare the same but I don't think the current crop of 'designer' shi-tzu, pug, chihuhua et al crosses will fare the same. many share the facial deformities of heir parents added to poor mouths which need early dental work and hernias which need surgical intervention not to mention the spinal problems and luxating patellas....
    Such data mining is really useful but there is so much more it doesn't tell us! We can't see if working type ESS or cockers fare better than showline ones. We don't know if euthanasia is due to health prblems or temperament problems and we don't know which are well bred from health and temperament tested parents and which from puppy farms.
    But when it comes down to it dogs bred for function and longevity (be they pedigree or mutt) will live longer! Dogs bred just for looks or for a silly name.....they won't.
    vp

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    1. yes it would be interesting to see a difference between responsible kc bred pedigree dogs with various health checks and caring start to life compares to puppy farmed pedigrees.

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  15. Interesting, but as several others have mentioned above, not conclusive of anything due to the numerous factors which would skew any conclusion. I don't agree that the majority of dogs who die at home of old age would be notified to their vets - certainly non of mine have been. I also think that the purebred v cross bred figures are less than reliable. Vets record dogs as being of the type/breed according to he owner. There are now lots of "almosts" out there whose owners consider them to the of the breed the highest percentage of parentage was, or the breed they most wanted from the parents - eg in Pugs, we now have 3/4 and 7/8 bred "Puggles" and "Jugs" being called pugs by the owners and being registered at the vets as such.

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    1. this is my primary concern with these results, I work in a kennel, and I cant count the number of dogs who owners list them as breeds they are not.. Shepherd crosses and Norweigen Elkhounds labled as purebred Malamutes, little spanial mixes labled as purebred CKCS. labs are listed as Goldens and vice versa all the time. not to mention often vet clinics dont have some breeds on their database and wont add it in, so they put the dog in their system as a mix, I have had my purebred listed as crosses on the vet records because the the person putting it in the system doesnt believe border collies come in a smooth coat. years ago I had a sheltie/BC cross whome the vet insisted was a Cocker Spanial and recorded her as such(she didnt have a single spanial trait lol) there is also the case of the way shelters lable breeds and the owners then take that as fact and keep that at the vet for the records..you know like a 10lbs "Rottie" and a 15lbs "GSD" or the Corgie I saw listed as a Staffy/Lab mix!

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    2. Yes, just peruse PetFinder and witness all the silly breed designations that are labelled..jindos, dingos, and Bavarian Sheep Shapers and other first time exotics.

      'Come on..anyone who works with dogs knows that this is a Labradoodle/Puggle Mix...'

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  16. The results are interesting, but little more than that. In the case of my own Labradors, the average age of those is around 13.4 with the youngest dying at 12 years 8 months and the oldest at 13 years 11 months. OK, I accept my small sample is statistically not as representative as the breed as a whole, but never the less, thats my figures.

    But when we talk crossbreeds I think we should also look at what sort of crosses they are. Obviously the ancestry of most is unknown, but the size of dog could be recorded, and would need to be to make it a fair comparison. By and large I think it accepted by most people that small dogs are longer lived than large breeds, and looking at crossbred and mongrel dogs as I walk around, most seem to fall into the smaller category, so I do wonder at the validity of the comparison.

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  17. What about the overweight 'killed by kindness' pets that we all see. Many pet as opposed to show/working dog owners have their pets overweight and thus will reduce life expectancy of that dog, be it mixed breed or KC Reg. This can affect any statistics. Unless any survey is properly thought out it is worthless.

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  18. A few notes after studying the poster
    0) Perhaps the most interesting thing in the poster is that cancer is the #1 killer...those concerned about dog welfare should look seriously at cancer statistics, and support research on causes of cancer.
    1) Why do they give the median and not the mean?
    2) 86% of the dogs in the survey were euth'ed and the second biggest reason for death is 'unspecified'. Does this make it a study of longevity, or age at which owners decide to pull the plug? I could imagine that the sorts of people who are attracted to different breeds vary in their willingness to live with canine companions suffering from 'old dog'problems, such as arthritic pain and incontinence. If euthanasia were legal and 86% of human deaths were through euthanasia, we would be looking at statistics very carefully.
    3) Presentation of statistics, and information extraction, could be improved. Eg, they state: "the median longevities for the Border collie and the
    English Springer Spaniel were higher than for crossbreds,
    although these values were not statistically significantly
    different (Table 1)." But Table 1 does not give the statistical significance of computed medians. It only gives interquartile range. Presentation of interquartile ranges shows that some breeds are all over the place, eg, the SBT, with a median of 10.65 and an interquartile range of 4.01-13.67 (~9.5 yrs), while other breeds are much more consistent, eg., the Lab has mean of 12.52 and IQrange of 10.71-13.99 (~3 yrs).

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  19. I posted yesterday from work and it never showed, so let me try again.

    1) I am curious: at least here in the States, many cross-breds (mutts) go through a shelter system at some point. The ones who are sickly or otherwise difficult to adopt often (sadly) end up euthanized. Would these dogs therefore be kept out of the cross-bred statistics, as they exited the database before having a chance to die of other causes? For instance, anything that looks like a bully-cross is likely to be euthanized unless it's an exemplary dog in all respects, because shelters in some parts of the country (not the northeast, but the south especially) are overrun with them.

    2) Here, most crosses have some lab/collie in them, two long-lived breeds. The small dogs tend to be terrier-mixes (again, long-lived). Surely that impacts the study? We know someone who has a lab-boxer mix, and at six years old she already looks old. That's the boxer genes showing. If more mixes came from these types of lines, surely that would tend to lower their lifespan?

    Finally:

    3) The majority of mutts are accidental litters bred by novices who are not experienced in whelping. In many (not all, of course, or even most) litters there are one or two pups who aren't thriving. Low birth-weight, sluggish, etc. Purebred owners of show and performance lines will often nurse these pups along and get them through. But common sense would dictate that at least some of these pups did not thrive because of innate conditions, and those that don't get enough colostrum don't have as strong of an immune system as those who do. Surely this impacts the dogs' longevity, especially against cancer? I just think that with mutts, many of the weakest pups are less likely to make it at birth, and therefore never show in the statistic. Natural selection has more of a say when those doing the whelping are not as experienced and skilled. Statistics show that low birth-weight babies are more prone to health problems as they mature. Surely the same is true of dogs?

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    1. "those that don't get enough colostrum don't have as strong of an immune system as those who do. Surely this impacts the dogs' longevity, especially against cancer?"

      No. It doesn't. Colostrum is passive immunity. The antibodies in colostrum are there to protect the puppy while it's own immune system develops. It has nothing to do with whether the dog itself has a strong or poor immune system of it's own as an adult.

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    2. You must be in a well off region. Here the main breeds in the mutt mix are pit bull and chihuahua. They tend to have short lifespans cause so many of them end up in shelters and don't get rehomed.

      I don't know about X-breeds in the UK, but in the US, a large number of them meet their demise without veterinary help. Far more than pedigree dogs.

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    3. Jess, I'm pretty sure you are only talking about one small part of what colostrum does. Plenty of studies in humans indicate those that are breast-fed do better, with fewer health problems, than those who are bottle-fed. And in dogs we also have studies of how colostrum, in particular, impacts development.

      http://www.nature.com/pr/journal/v18/n6/abs/pr19842011a.html

      We know that the digestive system plays a huge role in immunity.

      http://www.purinavets.eu/PDFs/ResearchReport_vol9-issue2.pdf#page=2

      I've only linked to two studies, but the body of research is pretty large. Lack of colostrum impacts development of the gastro-intestinal system, as well as leaving pups short on passive immunity, and that will have an impact later in life. So I stand by my statement.

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    4. Beth said: "Purebred owners of show and performance lines will often nurse these pups along and get them through. But common sense would dictate that at least some of these pups did not thrive because of innate conditions..."

      If a puppy that failed to thrive went on to a show home and that dog did well in the show ring, s/he would likely be bred from, despite obviously being weak stock. Surely this is part of the reason why pedigree dogs are less vigorous? http://flyingdogpress.com/content/view/18/94/ (Click on 'Selecting for Vigour' on the articles page; it's the 13th one down).

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    5. Correction: SOME pedigree dogs are less vigorous.

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    6. Fran: You are correct that in some breeds, breeders will keep typey dogs that have poor health/vigor and breed from them, which is part of the reason that SOME (not all, or even most) pedigree dogs are in such serious trouble. I have been posting to that effect here for a couple months or so.

      However, even in those breeds where most breeders do the right thing, and place pups who lack vigor in pet homes, those individual dogs contribute to the stats (but not the future gene pool) of average age of death.

      Then you have the trickier calls: if I have an entire litter that is not thriving and needs intervention, due perhaps to some non-genetic cause, do I pet out the whole litter, or do I say "Well, this was just bad luck and the line is good?" (I don't breed, personally, just to clarify). That's where judgement comes into play.

      Further, in many working dogs, historically (and often still currently) pups who don't thrive were left to their own devices. Now, from a genetic point of view, that is probably a good thing, at least some of the time. But from a human standpoint, is it kind or cruel to let a pup go if he might do just fine given some supplemental feeding, or by being put on another bitch with a smaller litter? You see, these questions do not have a black-and-white answer. One might argue that as humans we are rapidly weakening our OWN gene pool by medical interventions, yet my humanity tells me we should not sit by and watch while infants and young adults with treatable conditions suffer.

      Morality is never such a simple thing.

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  20. By the way, if you made the point (and you have in the past) that there are some breeds of dogs who have frighteningly short average life-span, and that perhaps these breeds should focus less on typey heads and more on breeding into long-lived lines (or maybe even out-crossing, if there is a similar breed with better genes), then I'd be whole-heartedly behind you.

    As it stands, the stats have so many untested variables as to be meaningless. The average mutt (who makes it to an age to be counted) lives 13.2 years. The average lab lives 12.5. That extra 7 months certainly is not going to matter much to me, if what I want is a duck dog and the mutt is not one..... On the other hand, I would not get a boxer or rottie because of the terribly short life span.

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  21. Insurance statistics regarding longevity are unreliable because once a dog reaches the age of (usually) 8 years, the premiums rocket upwards, with an additional percentage payable for each claim; many people decide that the benefits of insurance no longer outweigh the costs and so stop insuring. And of course if a dog isn't insured the insurance company has no idea when it dies!

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  22. mm - statistics.. I did a quick work out of the 8 dogs I've had of a largish, very healthy overall, breed, that have died. Their average age worked out at just over 12 - in fact 2 lived to 14 plus, two to just about 14, 3 to around 13 and a half - two died from different types of cancer at just over 10. The main problem with comparing pedigree with crossbreed is surely that so many have estimated birthdates. I also took on a Lurcher some years ago because he was 'very old' and difficult to rehome - I had him for a further 7 - 8 years! The real problem is the acceptance of a short life span in some breeds.

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  23. @Annie----------all the spaces are taken up by the people who have bred staffs without a second thought.
    Exactly Annie so how many of these statistic numbers of Pedigrees or crossbreeds were actually thought out ethical breeding plans. Lurchers etc it seems are as thought out as Pure breds according to posts on here but do come under the crossbred statistics

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  24. I can sympathize with all the people wanting a more detailed survey, but I know that there is only so much information that can be reliably gathered. Also, not everything can be evaluated. Time and money are finite resources for researchers, and they have to gather the information they consider most valuable. It is entirely possible that some dogs had incorrect data, but that's why large groups are so much better than the examples of individuals people like to put on this site. When there is a large enough sample size, it is more likely that an equal amount of dogs will have overestimated and underestimated ages at death. Sure, your dog may have lived to be much older than the average, but that just means you were a great pet owner, not that the statistics are way off.

    LJ

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    1. The Scandinavians do a great job. Go back to earlier PDE posts on longevity.
      If pedigree registries would collect death as well as birth statistics, and registries were open, we'd have a MUCH MUCH MUCH better basis for breeding healthy dogs. You can't do epidemiology without systematic collection of information on morbidity and mortality.
      VetComopass is better than nothing, but it would be much better if all pedigree dog deaths were registered . . . including cause of death. I would love to be able to recognise, and breed away from, lines that are prone to high incidence of cancer.

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    2. Absolutely right, Jennifer. What we need is something like an ISIS for dogs - an international database recording death and morbidity and other data. http://www2.isis.org/Pages/Home.aspx

      Jemima

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    3. In the database I would like a record of the vaccination status of each dog, i.e. no vaccination; puppy shots only; puppy shots and then one annual booster; annual boosters until middle age; boosters only every 3/4-years; annual boosters every year until death/old age/ill-health.

      Hopefully this would also highlight any health problems that could be linked back to vaccination or over-vaccination. For example, if dogs who only received puppy shots were far less likely to get auto-immune disorders, whereas those who received annual boosters were significantly at risk from getting auto-immune disorders, then this information could be used to prevent future dogs suffering. Additionally, if vaccination dates were provided and then dates of illnesses; a link may or may not be correlated to the vaccination.

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  25. By their very nature 50% of all cross breeds and mutts DOB are not known by their owners, and of those I suspect less than 20% have any actual proof or record, this survey is flawed from the the very start

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    1. I've had 12 dogs in my lifetime, 10 of them mutts, 8 of those rehomes or rescues, and only one has had an unknown date of birth. My current purebred(rarebreed and a rehome), is the one that doesn't have a date of birth as he went to his last owner through a dealer and they hide that info. My stats don't match yours so I have to ask where yours are from. Are you making them up or do you have a reference?

      Kary

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    2. Kary compared to you over four generations my familly have owned over 200 dogs all pedigree, should I use just their data to give a view for all dogs no, so to say your 12 dog experience is what you call Stats is suggesting a foolish thing, as for for your latest dog if he is purebred and rare breed, what type is he? as for him being bought from a dealer why would they hide what age he is? if that simple fact cant be supplied why would you eventhink he is the breed he is been sold as?!?

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    3. Anon 00:02. I did not suggest anywhere my personal numbers were stats or were to be extrapolated that way, did I? I was simply relating my experience, as some of us like to do sometimes, and suggesting they did not MATCH the 50% number given in the post above.:)

      I also did ASK about the reference source of that 50% number . . . ?

      As to my dog (my son's actually) he is a Tibetan Spaniel and identifiable by phenotype. He is show and table trained. I live in Canada where purebreeds are rare, making up approx. 10% of our canine population. There are less than 10 litters of Tibbies bred here yearly. He was offloaded to a dealer that I am familiar with by name for the same reason many retired purebred breeding dogs are run through this dealer. The breeders who originally needed rid of him obviously did not want to be identified and don't want him identified. Birthdates help with that if someone is zealous.

      Dealers in Canada bring many up from Southern USA (and Ireland too). AR has a strengthening presence where many Tibbies are bred in North America (Texas). Many breeders are keeping their heads and numbers low and moving out breeding stock they previously might have run on or kept on as older dogs as they duck newly imposed laws that are forcing breeders with even tiny numbers of dogs to keep them kenneled on non-porous surfaces and out of their homes.

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    4. Tibetan Spaniel a RARE breed ?!?!? snowmen might be rare in Sahara, but I wouldnt use that to prove a point in a discussion on globel warming!!!

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    5. Anon 5.33 you ID a dog by phenotype, really!!I suspect you would id all the Staffie crosses as Pit Bulls would you that have been captured under the DDA. Yet you called it a purebred but you have nothing to back it up other than it might look like a breed , off loaded to you by a doggy dealer! as for you saying you saying "I did not suggest anywhere my personal numbers were stats or were to be extrapolated that way, did I?" well inyour previous post you said "My stats don't match yours" yet the only source you quote is your own experience of your own dogs so yes you do give them as your personall numbers.

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    6. Anon - what are you reading! What point do you perceive I was trying to prove with the mention of the Tibetan Spaniel?

      I ASKED as question that has still not been answered. Where is the reference source for the statement made that "By their very nature 50% of all cross breeds and mutts DOB are not known by their owners."

      My experience, as an owner and a shelter volunteer of over 30 years, is very different to that so I don't believe the statement. Unless there is a reference source provided I won't believe the statement.

      Kary

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    7. Kary unless you can porove you actually owen a Tibetan Spaniel and not just a mutt who might look like one, why should you be belived either? you seen to make yup you mind on what you fancy and not what you can prove

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  26. I think it would be interesting to compare life spans today with those of 20/30/50 years ago. I have heard of a few pedigree breeds where owners used to expect lifespans of 15 years and up and now think 13 is a good age.

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  27. I would like to point out that removal of the fallopian tubes is being suggested as a superior option to sterilization for human women - lowers the risk of certain reproductive cancers, as they often originate in the fallopian tubes. Perhaps this could be done for dogs, as well - maintaining their natural hormonal cycles without risking accidental litters.

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    1. "...[A]s they often originate in the fallopian tubes." Really? This is the opposite of what a gynaecology consultant told me personally; he said the chance of getting cancer of the fallopian tubes was negligible. Essure is a non-surgical method of human female sterilisation, but does involve having nickel-titanium implants permanently in the body.

      I too would like to see a move away from removal of the reproductive organs to something akin to tubal ligation. However, a bitch would still come into season and could still be mated (including the problematic tie); she just wouldn't become pregnant. I'm not sure how well this would be received by the general pet owner population, but I would still like to have the choice. I'm not sure how feasible canine tubal ligation is, given that the anatomy of a bitch's reproductive organs are very different to those of a woman.

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    2. There would still be the problem of the bitch coming into season and being attractive and receptive to male dogs; although the resultant matings would be barren there would still be the associated problems of roaming, fighting and infection.

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  28. The KC 2004 data given above is not labelled. Are you comparing means in one set of data to medians in the other?

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    1. No - both give median longevity.

      Jemima

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  29. Ok . .. time to get geeky.
    Technically, life expectancy is mean age of death, not median.
    The usual reason to use median rather than mean is to surpress the effect of 'outliers' . . . oddballs that are very high or very low get. I suspect that VetCompass and the KC numbers have used medians is to get rid the cluster of deaths that happen in puppy years, eg., through parvo, behavioural problems, and puppies who aren't well cared for and get run over. If there are clusters of dogs who live to extreme old age, say 17 years or more, and this is not balanced by high puppy mortality, the median will be lower than the mean. OMG look at the breed data. (1) SBT's have the lower end of their IQ range at 4.01 years, Rotti's at 5.46. Why are a quarter or so of these breeds dying so young? And the Xbreeds group with the small terriers, Shih-tzu and bichon in having a quarter or more of their population passing 15 yrs. Does this mean the Xbreeds are dominated by little guys? Does it suggest that there may be a longevity gene that greatly increases life expectancy for some dogs with dwarfing genes?
    The bigger point: Even if the VetCompass data is biased, it contains some useful information. But the way it has been presented confuses as much as it clarifies. Somebody needs to work the data with a list of hypotheses to test and good statistician.

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  30. Off topic...sorry. The Gossip Dog blog appears to have dried up but a Gossip Hound facebook page has appeared.
    The same person, not the same person? If it is the same person their wit has got a lot less sharp but there are still one or two funny lines nonetheless.

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  31. With respect, 'crossbred dogs live longer than purebred dogs' is in many ways a nonsensical statement. Crossbreeds are just combinations of purebreeds, so it's impossible to make any statement of this sort without knowing the breeds that went into the crossbred dogs in the study. Most mutts in shelters seem to have collie, terrier, or lab in them, so if dogs from moderate breeds with broad and deep gene pools are contributing to the crossbred category, one would expect this to skew the data this way. Similarly, most breeds that are extreme or have weak gene pools tend not to get crossbred so much. A pug x bulldog is still a pure breed, but I wouldn't expect this to be particularly long-lived or healthy because both breeds share extreme features detrimental to the dog's health. The longer-lived purebred dogs in the study are all popular breeds and thus more likely to be owned by people prepared to allow 'oops' litters. In comparison, the short-lived ones are frequently such extreme conformations they have trouble mating with their own breed, let alone another breed in accidental and presumably time-limited circumstances, or too unpopular and rare to contribute significantly to accidental breeding.

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    1. Anon: Exactly! To say that the only thing that lives as long as a lab/collie cross, on average, is a lab. Or maybe a collie. shows nothing. I would expect that (on average) crossing a lab out with a bulldog would (presuming viable pups) result in an increased life expectancy compared to a bulldog, but a decreased one compared to a lab. I would expect a mix that was mostly Great Dane and Bernese Mountain Dog to have a similarly short life as either parent breed. While it may be true that you decrease the risk of certain recessive diseases by out-crossing, the research seems to point to size alone contributing to some cancers, hip disease, etc.

      There are some instances where a breed's biggest problem is too small a gene pool and resulting decreased vigor. In those cases, crossing two or three shorter-lived breeds with each other might result in a dog with considerably longer expected life-span. But that would be the exception, not the rule. And of course there are breeds that have such extreme conformation that they have resulting health problems, but breeding away from this extreme would likely decrease the problems without the need to outcross, and within a few generations. A few breeds are so riddled with genetic problems that outcrossing seems the only solution; breeding out CKCS with a healthier small spaniel might fix three or four ills in one shot.

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    2. "A pug x bulldog is still a pure breed"

      *confused* No, it's a crossbreed.

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  32. Hello Ms Harrison.

    This is kind of off topic for this post but. Remember those photos I posted of the Pekes. Here are some photos of some pugs in 1907. There on page 451. The pugs have a similar muzzle to the Pekes from the Victorian era. Hope you see them. - Fang.

    http://www.archive.org/stream/newbookofdogcomp00leigrich#page/450/mode/1up

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  33. I have had Papillons in my life since 1955. I find from my experience and that of other Papillon breeders that the average age seems to be about 15. I have had one to 20, and an Irish friend had one to 28. (Can be verified from guinness archive).

    Would be interested to know what your limited choice of breeds is based on.

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    1. Table 1: Median and interquartile range longevity values for dog breeds with more than 50 animals represented.

      From the VetCompass poster . . . caption to Table 1 (which JH reproduced).

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  34. Not many conclusions as sweeping as "Crossbreds live longer than pedigree dogs" are based on a study of 50 or so animals. Not much rigour there.

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    1. 50 is the cut-off for inclusion in the study. You can see in the table that the numbers range from 77 for Shih-tzus to 381 for Labs and 900+ for cross breeds.

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  35. I see two problems with the 2010 study and the poster:

    1) Size matching. As we know, small dogs live longer than large dogs. If therefore a large purebred does not live as long as a small mixed breed, how much of that is due to heterosis, and how much due to the size difference? To get a meaningful result, one would have to match mixed breeds with pedigree dogs of similar size.

    2) Right censored data. Both the study and the poster are based on dead dogs only. This means that any dogs from the same birth cohorts that are still alive at the time of data collection were not counted, which decreases the average life expectancy depending on population size, age distribution and how far back the data go. This can be expected to vary considerably between different breeds, which in turn makes such data less comparable.

    The problem of right censored data in veterinary life span studies has been known at least since 2008, and the authors of the 2010 study have admitted to their data being biased in that way in response to a letter to the editor pointing this out (J Small Anim Pract. 2011 Oct;52(10):555). The same is presumably true of the poster, which conveniently omits to admit this.

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    1. Censoring works both ways. You can have left censored(or left truncated) data depending on how the data is collected.

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  36. Thanks to everyone for their comments and queries on this... Dan O'Neill from VetCompass has responded here:

    http://pedigreedogsexposed.blogspot.co.uk/2012/06/purebred-v-crossbred-longevity-your.html

    Jemima

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  37. Really interesting to read, many thanks. I wonder what the relationship between inbreeding and longevity is? Or working ability and longevity?

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  38. Just lost my pedigree toy poodle at 19 years and 2 months, his card at the vets was only written on one side his whole life. I got his sister until almost 18. All my current poodles are non-related to that line; but I still have a 14 1/2 year old who still plays with the young uns and enjoys her walks on the field most days. My 12 year old is like a puppy. Lynne Land.

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  39. http://news.ucdavis.edu/search/news_detail.lasso?id=10498#.URx0FyTlTvm.facebook

    New research on the effects of neutering on the longterm health of dogs:

    "The research team reviewed the records of female and male golden retrievers, ranging in age from 1 to 8 years, that had been examined at UC Davis’ William R. Pritchard Veterinary Medical Teaching Hospital for two joint disorders and three cancers: hip dysplasia, cranial cruciate ligament tear, lymphosarcoma, hemangiosarcoma and mast cell tumor. The dogs were classified as intact (not neutered), neutered early (before 12 months age), or neutered late (at or after 12 months age)."

    "The study revealed that, for all five diseases analyzed, the disease rates were significantly higher in both males and females that were neutered either early or late compared with intact (non-neutered) dogs."

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