Healthy dogs: breeders and owners want the same thing

Best of Health

Sometimes, it’s easy to lose sight of what we’re all striving for. With vocal and polarised “camps”, the noise we hear often boils down to “ban x breed” at one end of the spectrum and “breed x is perfectly healthy” at the other. These positions are sometimes exacerbated by cherry-picking of data and evidence to prove a point or reinforce a position. What we all have in common is a desire to breed and own happy, healthy dogs, whatever our chosen breed might be.

I’ve written before that improving canine health and welfare requires a whole-systems approach. This is difficult because people with particular interests (or prejudices) are often only interested in proposing “simple” solutions to what is actually a complex problem. Another reason it is difficult is that there are too few tools and techniques that are widely understood for people to use in order to get a better understanding of the problem and to evaluate potential solutions.

I was therefore particularly interested to read a paper published in the Canine Genetics and Epidemiology Journal last month. The paper is open access and, although it includes some complicated analytical techniques, is well worth a read because of the novel approach it discusses. “Assessing the relative importance of health and conformation traits in the Cavalier King Charles Spaniel” asked a sample of breeders, judges and owners to assess the relative importance of health and conformation traits when selecting a Cavalier. The study was carried out by a team in Belgium (Wijnrocx, François, Goos, Buys and Janssens) with support from the Belgian Cavalier Club and the Cavaliers for Life Foundation.

By way of background, the plain English summary of the paper says: When selecting a future breeding dog, different disease characteristics and other traits have to be balanced against one another, which makes it a complicated task. In the case of selecting for a large number of traits, the exclusion of all affected animals might be very inefficient, since this may reduce the genetic diversity in a population or breed. A solution could be the use of a selection index, in which all traits of interest are combined into one single value according to their relative weight.

Attributes and choices

Wijnrocx et al chose Mitral Valve Disease, Syringomyelia and Eye Disease as important health conditions in Cavaliers that breeders/owners might be concerned about. They also chose a set of conformational attributes that might influence people’s choice of a Cavalier: Coat Colour, Eye Shape and Muzzle Length. Finally, they included 2 attributes that buyers and breeders would, typically, also consider: Price and Level of Inbreeding. These factors were identified and agreed through consultation with experts and key stakeholders. Clearly, many more factors could have been identified for inclusion in the research but there is a balance to be struck in order not to over-complicate the choices or to make them too burdensome for respondents. Even still, with the number of attributes in this study, the questionnaire was limited to 17 choice sets of 2 alternatives. Respondents were asked to choose between 2 different dogs that they would prefer to use as a breeding animal, given the various attributes.

The initial analysis showed that all the attributes were statistically significant, i.e. they mattered to the respondents, EXCEPT for price. Price was then excluded from the final modelling/analysis. Interestingly, the choices showed there to be no differences in preferences between breeders or owners. Both groups chose Syringomyelia (SM) and Mitral Valve Disease (MVD) as their top 2 traits to consider when buying a Cavalier. Incidentally, the choices they were presented with for SM and MVD were: (a) Tested and present, (b) Not tested or (c) Tested and free. Unsurprisingly, the respondents attributed a higher value to “tested and free” than the other 2 options. SM was prioritised above MVD, followed by Eye Disease. SM was more than twice as important as MVD and 5 times more important than Eye Disease, which possibly reflects the publicity given to the condition as well as respondents’ awareness of its welfare impact and the costs of veterinary diagnosis and treatment.

Respondents’ views of the level of inbreeding in their choices showed that they were concerned with levels over 6%. I checked the KC’s health website and discovered that the average Inbreeding Coefficient for Cavaliers is currently reported as 6.3%. So, breeding litters below this average would have been considered a positive factor by this survey’s respondents.

The “baby-face” factor

I was surprised to see that Eye Shape was scored as the third highest attribute (above Inbreeding) with the preference being for a “prominent” eye (the other choices being “small” and “wall-eyed”). This would seem to tie in with other research into buyer behaviour that suggests people are attracted to baby-like features when looking for a pet (hence the popularity of many of the brachycephalic breeds). The worry, of course, from a health and welfare perspective is that a preference for a prominent eye might result in dogs at risk of some eye diseases or of damaging their eyes. Muzzle length and coat colour were the lowest rated attributes.

While it would be easy to say that the findings of this study and the researchers’ conclusions are unsurprising and/or predictable, I think it’s an interesting approach to try to quantify a range of people’s opinions and place an order of priority on traits. Breeders have always had to juggle multiple traits when making their breeding decisions and, these days, the issues of genetic diversity and complex diseases make those decisions even more difficult and important. The authors describe this as “a first investigation in the rational thoughts of breeders and owners towards some non-economic traits such as desired conformation or beauty traits in the selection of a CKCS“. The work could be extended to include other traits but I’m not convinced that this would shed more light on what’s really important for the health of the dogs. It might be possible, eventually, to create a Selection Index for each dog that would be a measure of its value in the gene pool but the authors acknowledge that Estimated Breeding Values (EBVs) would also need to be known for each trait as well as some estimate of genetic correlation.

Priorities and practical steps

The reason this sort of analysis is important is that there are no simple answers to complex problems and, therefore, there will always be a need to identify and prioritise potential trade-offs when looking for solutions. The biggest risk of cherry-picking “simple” solutions is that they actually make things worse as a result of either unintended or unanticipated consequences. Techniques such as the choice experiment described in the Wijnrocx paper could be really useful to help develop a consensus on priorities and practical steps that can be taken to improve the health of dogs.

My closing thought for this month, with apologies to Eliyahu Goldratt: “The world of pedigree dogs is awash with ill-considered solutions to ill-defined problems”.










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