From Genes to Traits

Welcome to the WSAVA podcast. This episode, From Genes To Traits, explores the fascinating journey from DNA to the features, behaviors, and health conditions we see in dogs and cats. While you listen, ask yourself, how do the traits we value today shape the animals of tomorrow? This episode includes two conversations, Becky Murphy with Dan O'Neill, followed by Yaiza Gómez-Mejías with Petra Černá. Let's get started. How would you define breed in dogs? Where has it come from?

Breed is a human concept invented in the last 150 years. One of the myths for a lot of the public is that breeds exist in nature as something that have always been around. Dogs evolved maybe 10 million years ago and for the vast majority of their history, they've just been dogs. We've started inventing this concept called breed that really just came into the fore in the late 1800s.

There then was a mad scramble among humans to generate as many breeds as possible because there was money in it, there was status in it, there was kudos in it, there was prizes to be won at shows, so people went out actively selecting for mutations, diseases in dogs that were genetic and that they could breed into future generations and create new breeds.

So we started pushing what was a typical dog over the last couple of hundred years into multiple different shapes and creating new entities called breeds. So breed really is a human concept. It's not biological. We can change it. It's not set in nature. We can reinvent them to make them healthy. I see the creation of breeds as being an interesting thing because we are fixing traits such as temperament and behavior, or do we want them as a companion? Do we want them as a working dog?

And so forth. So do you think that there's enough diversity out there to actually fix some of the issues that you see in some of the breeds? What a wonderful question because intrinsic in that question is the sense of falling back into the same mistake that we have made over the past hundred years. Humans breed French bulldogs with French bulldogs to create French bulldogs. We have over 800 different dog breeds. They're all distinct.

They're all recognizable by the public and we only allow them to breed with themselves. There's loads of diversity. It just doesn't have to be within that breed. We can bring in genetic diversity from other breeds and when you think about it, every single one of the breeds we have today is a cross breed generated by crossing some previous dogs. Biology would say that we can and should be bringing in genes externally into breeds if it's needed.

As a veterinarian, we don't see people for pre-purchase consults. They come to us with the puppy that they've already fallen in love with and we can look at it and think, crickey, this is going to be a lifetime of difficulty. So do you have any advice to veterinarians on that first puppy consult on how to actually approach the discussion of extreme conformation and what they can do moving forward from there? I moved from general practice in 2009 into the Royal Veterinary College in academia.

I thought once I had the evidence, within three or four years the world would react, right? It has not happened. This is a long game. We have had a century of cultural brainwashing of humanity into believing extreme conformation is good. It will take many years to change the public zeitgeist to realize that extreme conformation is suffering. The vet profession has a huge role to play, but it really isn't all down to that single point of contact.

When the puppy first arrives, it's too late for that puppy. All the vets can do is try to provide the best healthcare advice and direct healthcare to keep that puppy above the cut point for a life worth living. Sometimes they'll go below that. If they go below, that euthanasia has to be discussed, but the wider role of vets can still influence.

It is a long game, non-judgmental and empathic conversations with those owners may help them not get the next dog, which might be 5 years, 10 years down the line, or maybe they're planning to get a second dog. So there is benefit in honest, empathic conversations from the client's point of view. The second thing we can do is speak as a profession. Most practices have social media, so we can use that to educate clients hopefully before they get the dog.

They're not going to pay for a consult in most situations, but they will see our social media messaging. Thirdly, we can help show owners by what we do. Vets and vet professionals should think seriously about the animals they own and the message we give even by walking your dog through the park. I've learned humans have a wonderful way to deal with cognitive dissonance.

We can accept, if I own one a dog with extreme conformation, I can accept that extreme conformation is really bad for the dog and the dog may well be suffering, but I will reframe it in a certain way that means that it's okay. And that means I would say there's a lot worse Bulldogs, he's one of the better ones and he's got a little bit of a tail and he's a rescue. I took him from a charity so it's all fine and I give him lots of love, therefore it's okay.

And trying to get around that is to try and put some objective measures that help the general public and the veterinary profession to understand extreme conformation. There are still lots we can do, but unfortunately by the time the puppy arrives in the consult, it's too late for that puppy. Absolutely.

So that conformation versus inherited disease, I think of things like BOAS, like IVDD, things that are a direct result of the conformation of the dog, the structure of the dog and then we've also got the inherited genetic diseases. So we are looking at things from simple mendelian traits, such as some of the progressive retinal atrophy, the blindness, to some more complex, multifactorial hip dysplasia that aren't necessarily related to conformation.

You go through the recommended tests for each breed, and it will list the DNA tests, the physical testing, the hips, the eyes, the respiratory function, and so forth. But we do often miss the point that they're only testing the inherited disease components of it. They're not necessarily looking at the conformational problems related to it, because we probably don't have a test for those things specifically.

What advice can you give to veterinarians when trying to consider those two issues as being reasonably distinct, but also having some similarities as well? How would you suggest that vets try and view them? I have a very contrarian approach, which means I disagree with everything, absolutely everything, until I've really tried to attack it.

It's like pinata, I'll try and get whatever the concepts are, beat the living daylights outta them and if I can't get the sweeties, I'll accept the donkey exists. I disagree intrinsically with the whole inherited disease concept. My PhD was called 'Acquired And Inherited Diseases In Dogs And Cats.' It, it covers everything in two species, right? It took me about six months to realize that every single disease in dogs and cats is inherited, every single one.

You might say, if a dog is hit by a car, that's an accident. It absolutely is not. It is an inherited disease, and we've published papers on this. Certain breeds are more likely to be hit by car, maybe because the people who own those dogs choose them and keep them inside because the dogs have less recall and maybe because the dogs have a greater tendency to wonder, all of those factors are inherited. So every disease has an inherited and non inherited component.

So the first thing is I disagree with boxing off disorders as inherited or not inherited. They're all inherited. Second thing is that I started this podcast with you by chatting about breeds and that we invented breeds. The only way that we could invent breeds and keep the future generations looking like the previous generation is if breed itself is inherited.

So we breed two French bulldogs, they're not going to give birth to a Jack Russell puppy, they're going to give birth to a French bulldog puppy or something that we define as looking like a French bulldog. If that puppy itself, because of its conformation, is associated with severe health issues, those are inherited diseases. The sad thing with that is that the world accepts standard diseases like diabetes and cancer and osteoarthritis is a bad thing. Everyone disagrees, it's a bad thing.

When it comes to conformational disease, we have humans actively desiring to own animals with conformational disease and that's why as veterinary surgeons, we have a really important role in trying to explain to the public that brachycephaly, inflexible spines and skin folds are every much as a disease as diabetes or some of the other examples. And that's why I said we've slipped into a century of getting it wrong as a veterinary profession and as humanity.

We have a long way to go but we do need to start that conversation and groups like the WSAVA Inherited Disease Group can play a key role in starting to break the old way of thinking. We are the veterinary profession, if animals can't rely on us to stand up for them, who can they rely on? Yeah. And I absolutely agree. Is there anything that we haven't covered that you wanted to wrap it up with? Let's deal with the outcrossing issue.

So outcrossing is another one of these generic holistic terms, but I often feel that they're not helpful as a broad term because for certain communities, outcrossing is taboo. So certain breed communities and people that have been breeding over the past 50 years, when outcrossing was not allowed, obviously it is now starting to be allowed, but it's hard for people to change their mindset.

So outcrossing is a term that, that probably should be used carefully and we should be using it in a qualified way. Outcrossing could mean within a breed, crossing between a working line and a shoreline, and that may be acceptable to some breed communities.

Outcrossing could mean that we're, let's say we're in the UK, Becky, you're in New Zealand, that we're crossing between breed lines within the UK, breed lines within New Zealand, that may have diverged, may genetically be different, make conformation be different. Those are ways to introduce new genetic diversity. Outcrossing can also mean going outside the breed, crossing with another breed, and then back crossing with the original breed trying to recreate the original one.

That was done, let's say, with Dalmatians where they had their uric acid problem, they were outcrossed with a Pointer and then after several generations crossing back with dalmatians, you have dogs that look identical to the original Dalmatians, but without the uric acid problem. Outcrossing can be designed for genetic diversity issues but also for conformational issues.

So we can outcross, let's say English bulldogs or French bulldogs with other breeds or lines, or with variants from other countries to reshape how they look. So with the Dalmatian example, the idea was to get it back to how it looked originally. With the French Bulldogs, if we're following innate health, we're trying to breed French bulldogs with long noses, tails, flexible spines, no skin folds. So we're trying to breed a healthy French bulldog.

Less about genetic diversity and more about actively changing how the dog looks. It's outcrossing to improve genetic diversity. It's outcrossing to move conformation towards less extreme, or in fact it should be towards a moderate conformation and then you can define how you do it. So almost when we're using outcrossing as a broad term, it's too broad, it's too non-specific and probably isn't helpful unless qualified by more information. Yeah. People like the breed types, don't they?

There are banned breeds around the world. In New Zealand, we have five or six. The, the whole concept of banning or as we call it, retiring different breeds, do you think that's a concept that will work? Or do you think that outcrossing whatever variation, it will be more successful over time? Banning or retiring breeds doesn't seem to work. It's a really good question because these are policies tried in different places at different times. The issue is humans. The issue isn't biology.

The issue is humans. I personally don't feel that banning breeds help. Breeds don't exist, going back to my very original comment, they don't exist in nature. The issue is the conformation, and I feel it is much, much better and it will be socially more acceptable if we approach it from a conformation point of view. The public don't like breeds being banned.

In the UK we had an XL bully ban because there was a high rate of people being killed by that breed, and it has been hugely problematic over the last two or three years, both from a human social point of view, but also a legal point of view trying to enforce it and even the big organizations, welfare organizations, disagreeing with each other as to whether a ban is good or bad.

But nobody will disagree with moving away from extreme conformation because extreme conformation by definition equates the suffering, either current and or future suffering. We should go with the line of least resistance and most gain. That's conformation. It's really interesting. What is one message that you'd like to take away from this podcast in terms of their role in safeguarding canine welfare? From a veterinary point of view, the big message is that breed is flexible and can change.

It's a human invented concept. Change, ideally should be within the domains that we physically, as humans, can change without necessarily doing lots of tests and lots of expense. They've allowed the pedigree dog brand to be tarnished by the extreme conformation conversation, and it is a huge issue, but it's the minority. It's less than 50% of the breeds. It's probably only 10 to 15% of the breeds and basically we have not started to celebrate the breeds that are physically healthy.

We keep looking at the ones that are extreme. There are lots of breeds. Labrador, Schnauzers, Greyhounds, Whippets, there are lots of breeds that actually innately are pretty good. Even though we have invented them as humans, we haven't actually got it that wrong in a lot of those breeds.

So from a vet's point of view, we can celebrate the good breeds and instead of constantly maybe having to bad mouth or talk down the bad breeds, we can just promote the good breeds, innately healthy breeds, and encourage owners to get them. Be positive in our messaging on social media. Be positive at an organizational point of view. For extreme breeds, as a profession, we can say your option is a moderate version of a French bull dog with a tail.

Currently in the UK, within the pedigree community, for example, the ones that happen to be born with tails tend to be neutered because they're, I'm using inverted commas, they're wrong. We're fighting against nature. If you give nature a chance, nature will regress to an innately healthy dog.

If you, not that I'm advocating everybody gets a street dog, but if you look at street dogs, they look the same long tail and a long nose and flat skin, and their eyes sit in and their leg proportion is correct. That's what nature will regress to, and it'll do it within two or three generations. So vets can be positive, non-judgmental, empathic about getting innately healthy breeds and then within the breeds that have severe issues with extreme conformation.

Again, without judgment, we can say yes if you want to buy that breed, move towards the healthy versions, and we can do that and within a couple of generations, that can be done After Becky Murphy's discussion with Dan O'Neill, the conversation continues as Yaiza is joined by Petra Černá. Before any planned mating, vets can perform several types of exams to identify potential health issues and prevent hereditary diseases from being passed on to the offspring.

These assessments generally fall into three main categories, clinical, phenotypic, and genetic. Genetic screening was discussed in previous episodes. Now, following Dan and Becky´s conversation on how to move towards healthier breeds, we´ll explore how veterinarians can help ensure that breeding cats are fit for reproduction, through phenotypic exams and clinical screening.

Clinical exams focus on the animal’s overall health and function, whereas Phenotypic exams assess the observable traits, what we can actually see. These include features such as coat colour, body size, ear and tail shape, conformation, and structural soundness, such as healthy hips or a heart free of hypertrophic cardiomyopathy [HCM], the most common cardiomyopathy in cats.

When we hear the word screening in a health context, we generally think of tests and what type of tests does phenotypic screening involve? When we look at phenotypic features in pedigree cat, we actually do not have tests for absolutely everything.

So one of the tests we would look at, for example, would be doing an echocardiogram for HCM in cat or radiographs to assess for hip dysplasia in cat but there are a lot of phenotypic features, bigger ears, for example, and these are things you just can't really test for. So I think these are very often things where we have to use some common sense and just really make sure that the cats we are using for breeding are healthy cats that have good quality of life. So heart ultrasound, radiography.

Just from the physical examination, we can gather some useful information as well. And compared to genetic screening, what are the strengths and limitations of this type of phenotypic screening? So I think one of the strengths with  phenotypic screening is that we do not need to have a known gene for that condition. But I think one of the biggest limitations will be that these are things where we cannot just do a simple swab or saliva collection to get results.

So big, probably limitation will be access to care because not every person is in the same kind of location, and then there will be a difference in which people can access what type of testing. So I feel very lucky and privileged living in the United States, working at the huge university, and really having an access to any possible test that exists in the world. This will not be true for people that live in other places in the world. So this definitely could be a challenge.

And then I think another big limitation is interpretation of these tests because it's great when we know this is the gene and then we do that genetic test, but I think analyzing or interpreting genetic testing can be much easier. The cost can also be challenging. So you know, repeating echocardiograms annually can definitely be quite an expensive cost, even if you have access to board certified cardiology.

So unfortunately, when it come to phenotypic screening, a lot of the things are very limited. What advice would you give to those general practitioners that are willing to do screening, but they lack of the confidence to interpret some tests like heart ultrasound or perhaps they don't feel confident in interpreting a, a hip x-ray in a cat?

Interpreting feline hip radiographs can definitely be much more challenging than in dogs because of course, cats are not small dogs and their hips will look very different even when they're healthy compared to dogs. So what I would strongly recommend that before you even sedate the cat for radiographs, you actually check either the PawPeds or OFA website.

Look for guidance because you can send the radiographs for assessment to either PawPeds or OFA, and those can be read out by specialists who are very comfortable with grading feline hips. But I think it's very important that we would have a good quality radiographs for this. Our biggest challenge here is that if those radiographs are not good enough quality, then nobody will want to actually assess them.

So before you spend the client's money, before you sedate those cats and put them through all of this, maybe just do a little bit of research on those websites. If you are not sure, you can reach out to them or some orthopedic specialist or some of your colleagues who have experience with this and just get some guidelines on what radiographs you exactly need, how the cat should be positioned. I definitely recommend doing some research on this topic. That's great advice, thank you.

When it comes to more hidden things like cardiac disease or hip dysplasia, at what age do you start talking to the owners about testing for this? I think it very much depends if the kitten is completely subclinical and they just want to use the cat for breeding, once the cat reaches that age of about 12 months.

For echocardiograms, I usually recommend that, especially in those breeds that are predisposed to HCM and we have no genetic testings available, such as British Short Hairs, Persians, and exotics, for example. But those breeds like Rag Dolls and Maine Coons that are predisposed to HCM, we know only about the one gene that is available. So the cats could still get probably HCM even when they do not carry that mutation.

So I would strongly recommend getting a first echocardiogram before the mating. So, and around that 10 to 12 months of age. So we know the heart is normal before they go on. But the biggest issue with phenotypic screening is that especially with heart disease, things can really change. So then we recommend screening ideally annually or at least every other year for these cats. For hip dysplasia, this is a little bit more challenging.

I've seen horrible hip dysplasia in kittens as young as about five, six months, so it can start very early. Again we would want to make sure we get clear hip radiographs without severe hip dysplasia before the first mating, but some breeds like Maine Coons, they really can take a long time to develop. So ideally we would do those radiographs again around 12 to 14 months, but some cats might already need to be mated by then.

So if we had done them in younger cats before the first mating, we might want to consider repeating those in the future. Would you still perform heart scans in those cats that have been through the genetic testing? Absolutely. At the moment we still dunno enough about the HCM in cats, and I think even though they do not carry that one mutation, we know that of course those cats could potentially still develop heart disease.

It's less likely but there is still a chance because there could be other mutations causing that. I think until we have a more idea on actually how these genes show in terms of what age they would show the disease at, I really would recommend before any mating that we screen these cats. You are forever responsible for what you have tamed, and I do believe that we are responsible for the kittens we breed.

So if you wanna be a cat breeder, you really should do your very best to make sure you are breeding healthy kittens. How can phenotypic screening them help differentiate between inherited disorders and non inherited conditions in cats? I always think that there are a lot of conditions in cats that they might not be fully inherited, at least in that way, that they would show in the parents and then show in the offspring. Some of these can skip generations, right?

Especially when it comes to hip dysplasia, heart disease, so the fact that the parents have been screened doesn't mean that the kitten will not have it. There is definitely this environmental factors and genetic factors to hip dysplasia. There's probably some incomplete penetrance, or the hereditary conditions of the hip dysplasia are not a hundred percent clear. For the hip dysplasia the phenotypic screening really needs to be done in the parents, but also even in the offsprings.

I wish everything was as simple as the recessive or dominant traits because then we know that if my cat does not carry the mutation, I know I don't have to continue testing all of the offsprings because there's no way when it comes to phenotypic traits, this definitely is a much bigger challenge test for at the moment. I think maybe someday we'll have a easier way than just test for at the moment.

I think maybe someday we'll have a easier way than just doing a CT of the skull on these cats and deciding which ones maybe could be used in mating or not. But I think just looking on a physical exam in those cats and making sure that the cat doesn't have too narrow nostrils. So BOAS is, in my opinion, a little bit simpler probably in cats than in dogs because most of it we can see actually externally, right?

So I do not have to put the cat, like I have to do with the dog, under general anesthesia, really check the soft palette and all of that. Most of it I really can see on my just basic physical exams. So talking to the clients when the cat has too narrow nostrils, that this really should not be a cat that should be used for mating or if they have a chronic ocular or dental issues, because we know there is a lot of overcrowding of the teeth in these brachycephalic cats.

And just discussing all of these conditions and external kind of things we do see in these brachycephalic cats and making sure that people try not to using these cats for breeding. So, yeah, even if you weren't sure that the trait you've got in front of you is not inherited or is inherited, would you encourage the person not to breed from the cat? Absolutely.

I think a brachycephalic cat that struggles to breathe on its own, it's probably really not a cat that should be put through the stress of pregnancy and having kittens and until we know little bit more how brachycephalism is inherited and how it develops, there is plenty of cats out there everywhere. So really breeding cats that have some defect that really is severely affecting their quality of life and health and welfare is a huge problem.

So we really should not be using those cats in mating and just generally supporting the breeding of these cats that are struggling with health and welfare. So I do love all the cats in the world. Anytime I see a cat suffer, it is causing me severe stress and breaks my heart. So I definitely do not want to see any cat out there suffer and we already have enough diseases that cats can just get as they age. So why would I already breed a kitten that will struggle for the rest of its life?

You are a judge as well at breeding shows, but you've been judged as well because of being a breeder. And what tips would you advise?

Because we have this tension in clinical practice where as general practitioners, we feel frustrated about not being able to do anything about this whole cascade of events that come from this systemic problem of a society that breeds abnormal cats and that we are shaping the body of these species and up to an extent that sometimes these shapes wouldn't enable them to survive in a natural environment.

So I understand where the frustration comes from, but at the same time, we need to collaborate with other groups and professional groups and non-professional groups. What would be your main advice when it comes to communicating with the people who may not be aware of the severity of these traits? I always try to presume that when people have cats or breed cats it's because they do it because they really care about the cats and they love the cats.

We definitely have those backyard breeders where they could be doing it for financial gain. In 20 years I've been breeding cats. I've never made a single penny, with actually every litter I feel like I lose money and it's a very expensive hobby to keep. So I would always try to presume that people do what they do because they love cats and they care about cats deeply. Very often I come across the fact that people just don't know any better. So when we know better, I feel like we do better.

So I try positively educating the clients, trying to really tell them and explain them that what they didn't know is really important and that this cat really has an impacted quality of life. And then health and welfare of the cat is of course, an issue because as a veterinarian, but also as a breeder and as a person that loves animals, and the cats, of course, very deeply, those creatures cannot speak for themself, and we are their advocates.

We are very much responsible for raising those health and welfare concerns because those animals cannot do it themselves. So I do really believe when I see a cat welfare or health being impacted, I really need to say something. Otherwise I cannot be able to sleep with myself at night. Sometimes I definitely gain unpopularity, but I don't do what I do to be popular. I do what I do because I believe in it, and I do believe that it is my responsibility to raise those concerns when I have them.

And so this is what I would recommend to people as well. Try being positive about it and of course then you work with breeders, making sure that when you are raising those concerns, that you're trying to educate them.

Because I, again, most of the times they just don't know this is a problem and when you educate them positively about it, they're much more likely to make a change than when you are very negative and you feel like you are judging them because I feel like that's really not going to lead to any change at all. Thank you. Yeah, I think that's very helpful.

I think there's a place where we can talk from our love for cats and we share that love for cats and that shared understanding of our love for cats is a good place to speak from, isn't it? Most of these people may not be aware of all the traits associated with their cat's breed, and they just want to be informed about the dangers associated with them.

One has to be prepared as a vet to, to give a basic advice on what to do next, because obviously they've already adopted the cat and they're not going to give the cat back and they want to keep it. And the next question that the client is going to ask is, what do I do now? How can I prevent this? How can I sort it out? When you tell them you can't do much to sort it out they're going to be frustrated.

As a health professional, you have to give them some, some sort of tools to cope with that situation and, and try to gain some agency and at least give them some tools to monitor their disease if it appears, and for them to be prepared. Yeah. And act when necessary, and especially assessing their quality of life. That's a wrap on season one of the WSAVA podcast. Our thanks go to the Hereditary Disease Committee for leading this fantastic series.

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