Now, a new study from Finland confirms that Bulldogs suffer from serious orthopaedic disorders - including an abnormal gait, slipping kneecaps, spinal malformations, elbow dysplasia and severe hip dysplasia.
The radiographic study, of 24 ostensibly-healthy young Bulldogs registered with the Finnish Kennel Club, found the prevalence of orthopaedic disease, particularly hip dysplasia, so high in the breed that "no healthy individuals exist".
All but one of the dogs had moderate or severe hip dysplasia. Three-quarters had at least one malformed vertebra. Thirty-three percent had luxating patellas and almost half of the dogs in the study had elbow dysplasia.
The orthopaedic abnormalities are linked to kennel club breed standards which ask for a large head, a broad and heavy front end and lighter, narrow hips, all of which result in extra stresses on the dog's skeleton.
Worryingly, the research suggests owners are unaware of the problems and that the iconic British breed may be enduring significant undiagnosed and untreated pain.
"One of the most worrying points of our study actually was, that the owners of the dogs we studied, did not feel that their dogs were sick or poorly, which is alarming" says lead author Anu Lappalainen. "It is important to note that many of the 'everyday behaviours' of these dogs are often actually symptoms of pain or discomfort, but due to the amazing but at the same time hard to interpret, stoical temperament of these dogs, these symptoms are often not noticed or understood."
Based on her clinical experience as a vet, Dr Lappalainen says she was expecting to find a number of issues but "the severity and amount of them was surprising to us."
The study, funded in part by the Finnish Kennel Club and supported by the Finnish English Bulldog Club, is actually the third published using this cohort of dogs.
The first found that every Bulldog in the cohort (aged 2-5) showed some signs of breathing difficulty, almost half of them moderate or severe. The second found that all showed abnormal dermatological findings, too - 37% unrecognised by their owners.
So to sum up, every single one of a cohort of Finnish Bulldogs reported healthy by their owners was diagnosed with breathing, joint or dermatological issues - and all but one suffered from all three.
Asked if the sample was large enough to be able to draw conclusions about the breed in Finland as a whole, Dr Lappalaeinen says: "Considering our research methodology, the sample size was sufficient, and our findings are noteworthy. Regarding the sample size, the key word is 'sufficient'. Modern clinical research aims to achieve reliable results by using as low numbers of animals as possible, so that we do not stress any more animals than we absolutely have to. This research was a prime example of how the examinations that the dogs were subjected to - albeit it was only walking for a kilometer, or lying on their side - were very strenuous to some of them, and thus, the less animals needed to be subjected to these tests, the better."
Even allowing for the fact that some of the conditions were mild in some dogs, and of course these were just Finnish Bulldogs, it is an astonishing finding - and little wonder the authors conclude:
"For the future of the English bulldog breed in Finland, it seems unlikely that any changes in breeding could produce healthier individuals when taking into account that the prevalence of orthopaedic diseases is high and in some conditions like hip dysplasia, no healthy individuals exist. In addition, orthopaedic problems are not the only condition that plagues this breed. At this point, the chances for selective breeding are lost and probably the only option towards healthier dogs would be crossbreeding."
They are not the first to conclude this. A study from UC Davis in 2016 found that despite their huge numbers, the breed had such low genetic diversity that it would likely be impossible to breed away from their myriad of health issues without outcrossing to a healthier breed. The study provoked uproar from Bulldog breeders who claimed lead scientist Professor Niels Pedersen had got it wrong.
And that, sadly, is likely to be the response from Bulldog breeders to this research too. Here's one comment I saw about the study.
I do think it's important to recognise that some Bulldogs breeders are working hard to produce healthier dogs. We've seen that some do lead reasonably active lives; that some even do agility and other dog sports. There's more health testing too - and clearly they are much loved by their owners.
But it is ethical to continue to breed dogs that suffer this much?
The answer, surely, is no.