Trust or trash? Just what can you believe?

The annual KC Breed Health Coordinator (BHC) Symposium was, for the first time, opened up to people who are not BHCs. As a result, around 200 people attended the event which featured a packed agenda of topics. There has already been an overview of the day published in Our Dogs (13/10/17) but, this month, I want to focus on one of the sessions I found particularly interesting.

Sniffing out the science – how to interpret information on dog health”, was presented by Dr Zoe Belshaw from the Centre for Evidence Based Veterinary Medicine at Nottingham University. I am an avid searcher for, and reader of, scientific papers and other published information on canine (and human) health and genetics. There are a couple of basic challenges; knowing where to look and knowing what to believe. Remember, we are increasingly living in a world where so-called Fake News pops up, especially via social media. Zoe’s presentation addressed both of the challenges. Let’s start with knowing what to believe.

Almost every day, new scientific papers are published or there’s a blog post (often cross-posted onto Facebook or Twitter) with a mix of data, evidence, insights and opinions. There is ALWAYS a risk of bias in these; every author brings their own agenda. As readers, we also bring our own biases and I’ve written before about Cognitive Dissonance. For example, many people simply look for information that supports their existing opinions and tend to reject anything that goes against that opinion.

Another reality of published information is that there may well be different conclusions drawn about the same issue. That might be a result of bias or it might be related to the methodology used by the author in their study. An obvious example would be the different results published by Dan O’Neill’s VetCompass project compared with results from a Breed Club’s Health Survey. The two sample populations are completely different. VetCompass data comes from first opinion vets using standard VeNom classification codes for different health conditions. Many breed surveys will not use those codes; they may use categories that reflect terms in common use by “ordinary” owners. The population being sampled is also likely to be different; mostly breeders and exhibitors. It might therefore not be surprising for VetCompass to find the most prevalent diagnoses are Otitis, Dental disease, Anal sac impaction and overgrown nails, whereas a breed survey may be more likely to find issues such as PRA, epilepsy or allergies. They are both “right”, based on the methodology and the sample. In my breed, our Health Committee has always taken the view that we need to triangulate in on priority health issues by using a variety of evidence sources. As we find new information from different sources, we can tweak our approach and our priorities. For example, we amended some of the categories and conditions we list in our ongoing health survey as a result of the 2014 KC survey.

The Trust Triangle

Zoe talked about the Trust Triangle which describes the different types of information you might come across and the levels of trust that can be associated with each.

Trust TriangleAt the bottom of the Trust Triangle are non-experts with opinions. Facebook and social media are awash with these! Journalists and experts with a commercial interest also fall into this category. Next comes expert opinion; these are people who are widely acknowledged to be experts in their field. Many of them will know an awful lot about a very narrow field of science. They too come with their biases and personal agendas but, mostly, they will have years of experience and scientific data to back up their opinions. Moving up the Trust Triangle, we find primary scientific research. This is made public via “papers”, the best of which will be peer-reviewed, rigorous, well-reported and independent. At the pinnacle of trustworthy published scientific research are papers that present systematic reviews of multiple other studies. These publications dissect and critique a set of primary research papers in order to arrive at “the best evidence” to support a particular case (or to disprove it). This is the sort of work that Zoe’s colleagues do at the Nottingham Centre for EBVM and they then publish what can be considered to be best practice for vets and clinicians to adopt. As with all science, “best practice” today could well change if new research evidence emerges. A topical example is vaccination protocols where advice from WSAVA should have moved vets away from “annual boosters” of core vaccines to a less frequent regime (no more frequent than every 3 years, generally) or the use of titre testing to assess levels of immunity.

One potential issue with the Trust Triangle is that, the higher up you go, the less accessible the information becomes and, often, it also becomes more difficult to interpret and understand. At the base of the triangle, keyboard warriors and instant experts often use language pitched at a level that you’d expect to find in the Daily Mail (or Beano). At the top of the triangle, the language is (rightly) riddled with scientific terminology and often supported by statistical analysis that is impenetrable to the ordinary dog owner or breeder. Those of us who are interested in this material may need help from subject matter experts to interpret it and clarify the meaning so we can share it with other owners. The KC’s Health team and other Breed Health Coordinators with science, veterinary or research backgrounds are invaluable in this respect. Most BHCs will also have built a network of trusted specialist advisors to whom they can turn for advice when a new paper is published. We should be hugely grateful that people like Cathryn Mellersh, Dan O’Neill, Clare Rusbridge and Sheila Crispin, to name but a few, are so generous with their time and support to our breeds.

There’s a useful resource which Zoe pointed us at to help decide if we should “Trust it or trash it” ( This takes you through a series of questions to identify: who said it, when they said it and how they know it. She also gave examples of good ways and places to find the information we need to support the development of breed health improvement strategies. These include Google Scholar, RCVS Knowledge, PubMed, BestBETS for Vets and VetSRev.

As champions of breed health improvement, BHCs can make good use of social media to communicate with owners. It enables them to reach a wide audience, for example through breed-specific Facebook Groups. What they communicate, however, needs to be distilled from evidence sources higher up the Trust Triangle.










Show me the data and I will show you insights and solutions

Some readers will remember me writing about the Dachshund Breed Council’s 2015 Breed Survey: DachsLife 2015. The aim of the survey was very specific – to identify any lifestyle factors that contributed to the risk of back disease (IVDD). The original survey design was done in conjunction with Rowena Packer and her colleagues at the Royal Veterinary College (RVC). We deliberately involved them in the design because we had ambitions to gather lots of data that could be used to build on Rowena’s earlier work on the conformational risk factors associated with IVDD. In 2013, Rowena published her paper “How long and low can you go?” which showed that the longer a Dachshund’s body, the higher was its risk of IVDD. This clearly had implications for breeders and judges, but we also wanted to explore what owners could do.

After we had reported our results, we handed the data over to Rowena to work her magic with the more sophisticated statistical analysis tools she has available. Now, we have just published that further level of analysis in the peer-reviewed journal of Canine Genetics and Epidemiology.

One of the great things about this journal, which is sponsored by the Kennel Club, is that all the articles are Open Access. I strongly believe that sharing data and making the results of scientific studies widely available is key to making progress with any sort of improvement. So, not only can readers read the full text of our paper, but they can also access the anonymised source data. Anyone can repeat our analysis and interrogate the data further.

“Without data, you’re just another person with an opinion” (Dr. Deming)

As soon as data, research and analysis are put into the public domain, people can begin to make informed decisions.

Of course, the data and analysis may well challenge existing preconceptions and urban myths. Our Dachshund analysis was no different. Conventional wisdom would have you believe that allowing your Dachshund to jump on/off furniture, or to run up and down stairs is potentially bad for their backs. The analysis actually showed the reverse; those dogs who were allowed to do those things had a lower odds of having IVDD.

We do have to be careful to remember that correlation does not imply causation and we point out in the paper that there may be a danger of “reverse causation” with some of the results. For example, it may be that dogs whose backs have herniated were subsequently not allowed to jump on/off furniture or go up/down stairs. The missing data is “when” did those activities start/stop in relation to the herniation. We can, however, find other studies which also showed that this sort of activity reduced the risk of IVDD. The practical advice for owners arising from the activity/exercise findings is that keeping your Dachshund fit and active is one way to reduce the risks of IVDD. It’s common sense and any reasonable person would expect a fit, well-muscled dog to be able to lead a normal lifestyle coping with furniture and stairs.

Another surprise from our analysis was that neutered/spayed Dachshunds had an increased odds of IVDD compared with entire dogs. In this case, we can be more confident that it is not a case of reverse causation (e.g. dogs with IVDD were subsequently neutered) because we know the age of neutering and the age of IVDD diagnosis. Indeed, we found that the younger a dog was neutered, the higher its odds of IVDD. This finding should not surprise us in light of numerous other studies in dogs (and people) that challenge the claimed health benefits of neutering.

This finding is going to be a hard one to sell to many vets who still seem keen to encourage new puppy owners to book their dog in to be spayed/neutered as soon as possible after its vaccinations or before 6 months of age. However, in this emerging age of evidence-based veterinary medicine, vets will, I suspect, find some of their prejudices and biases challenged.

Big data gives you big insights

One of the interesting challenges when the paper was peer-reviewed was around biases in the data. The survey participants were self-selecting, they were willing to “own up” to health issues in their dogs, they may have been keen to “make a point”. They all responded via the internet in an online survey, so there may have been demographic biases in the respondent population.

Our argument was that, if you have large volumes of data, these sorts of bias are less significant. We had over 2000 responses and looked at more than 50 variables in the lifestyle factors. The VetCompass project is similar; with literally millions of case reports from first opinion veterinary practices, the volume of data permits deep insights to be obtained with high statistical confidence.

Of course, we have to remember that epidemiological studies draw conclusions about populations, not individual dogs. Inevitably, there will be owners whose personal experience differs from the findings at population level. In our case, there will be comments like “my dog jumped off the chair and ended up paralysed” or “my dog was fit and well-muscled, but still had IVDD”.

Those individual cases are entirely to be expected and do not diminish the advice we are able to give owners based on population-level insights. We know that, fundamentally, IVDD has a strong genetic component and is highly heritable. Nevertheless, if every owner adopted the good lifestyle choices we have been able to identify, I am convinced that it would make some inroads into the risks of IVDD. I’ve written previously about Dave Brailsford’s 1% Principle: lots of small changes can aggregate to make a significant difference.

While I have focused on Dachshunds and IVDD in this article, I am sure the principles apply more widely:

  • Breed Health Coordinators and their committees should think about the design of their health surveys with a view to carrying out deeper analyses
  • There are many situations where breeds already have lots of data; collecting more or different data is not the solution; we often just need more insight from analysis of existing data
  • The answers lie in the data, but don’t be surprised if some people (owners, vets, breeders) feel challenged or exposed by this, particularly when the results run counter to their perceived wisdom (see my article on Cognitive Dissonance)

Finally, remember “Prejudice is a great time-saver; it enables you to form opinions without having to gather the facts”.

The Great British Puppy Survey

GB Puppy SurveyI’ve recently finished reading The Great British Puppy Survey 2016 which was organised by a group of independent dog and animal welfare campaigners. They are Canine Action UK, CARIAD, Hidden-in-sight, The Karlton Index, Naturewatch Foundation and Pup Aid.

This group wanted to examine the behaviours and attitudes of UK puppy buyers to provide data that might inform future campaigns and policy-making, with the overall aim of improving welfare outcomes for dogs.

The online survey ran for a year (January 2015 – January 2016) and received 4303 responses, of which 3670 were described as “complete”. The responses comprise both quantitative and qualitative data, from a mixture of multiple choice/ranking questions and free text questions.

The first question you have to ask is to what extent that sample size is statistically significant. If it’s not, then any conclusions and, more importantly, any recommendations may be flawed.

Virtually all the puppies (97%) were purchased by survey respondents between 2010 and 2015 (6 years), a period when a reasonable estimate of total UK puppies bought would be 750,000 per year. Given that population, a quick test shows that a sample of 4000 responses would lead to a Confidence Interval of +/- 1.55 at the 95% Confidence Level. In other words, we can consider this to be a big enough sample upon which to draw statistically significant conclusions. We do, however, also have to consider the potential biases in the sample and their responses.

70% of people had bought a pedigree dog and many of those who had bought a crossbred had chosen a so-called Designer Breed, such as a Cockapoo or Cavachon. Interestingly, 80% of people had previous experience of owning a dog, so this does introduce a particular bias to the results. You would assume that the buying attitudes and behaviours of people with previous dog-owning experience would be somewhat different to those who had never owned a dog.

Unfortunately, the data presented in the report has not been analysed in this way, but it would be very easy to do this. I would be really interested to see if new owners were less rigorous in their research and decision-making process than experienced owners, or if they ended up with puppies that had more health and welfare problems. This could be important to help determine whether communications to the two groups should be different. There has been some interesting evidence published, based on Government (HMRC) “nudge” communications. Using language that is tailored to the audience has improved compliance rates in letters about tax returns. For example, “9 out of 10 small business owners like you have already submitted their Tax Return” gets a better response than “your Tax Return is overdue”. A similar approach could perhaps be used with puppy buyers to help them in their decision-making.

Pre-purchase Research

Half the respondents researched both “responsible dog ownership” and ”different breeds” via books, magazines and the Internet before buying their dog and 1 in 8 consulted the KC for advice. 15% asked their vet for advice, which I suspect is a reflection of the number of existing/previous owners in the sample. I’d be surprised if a first-time buyer would consult a vet. Perhaps surprisingly, 15% also visited dog shows to find out about their preferred breed. This is obviously encouraging and a good reason to make shows welcoming to visitors. Only 2% of these respondents did no research, which again suggests to me that many of the responses are slightly skewed by the 80% who had previously owned dogs.

Online classified websites were the main source of adverts, with Pets4Homes being used by about a third of buyers. Having found a breeder (or seller), nearly one-third did an online search for that person’s name. That, I think is interesting and positive as it is more likely to throw up articles on puppy farmers and welfare issues that have made it into the public domain.

Puppy sellers

There appears to be significant confusion among the puppy-buying public about licensing, KC Registration and accreditation (e.g. ABS membership). Half the respondents did not know the difference between people who were selling KC Registered puppies and those who were ABS members. In another question, buyers ranked “the seller was licensed” at number 7 in importance to their buying decision, compared with “able to see mum” and “right breed, sex, temperament” which were ranked first and second. It would appear that “licensing” or accreditation are not high in the priorities of buyers and, given the numerous puppy farm TV programmes where premises are licensed, there is probably still a big credibility gap to bridge. I wonder if the tarnished reputation of Local Authority licensing is carried over into scepticism over the value of the ABS. Surely, UKAS accreditation is the factor that differentiates the two.

In this survey, 80% of buyers saw the puppy’s mother when they bought their puppy. That leaves a shocking one-fifth who didn’t and suggests the “See Mum” message has much more work to do. Add to that the evidence that dealers and other less reputable sellers are setting up “fake Mum” situations to hoodwink buyers and it’s clear that “see Mum” might be overly simplistic as a single message to buyers.

Post-purchase experiences

One in five buyers reported problems with their puppy that required veterinary treatment. Of those, just over a third developed symptoms within the first week of ownership, with 1 in 20 facing vet bills of over £3000.

It’s probably not surprising that so many issues emerged in the first week of ownership as it can be a stressful transition for any puppy, however well-reared, as it moves to its new home. However, there is plenty of research evidence that the temperaments of poorly-reared puppies are worse than those from a good welfare background and you would assume that well-reared puppies will have a less traumatic transition. This also raises a strong argument for puppies to have only one transition; that is from their breeder to their new home. Transport between commercial breeders and retailers, via dealers, and time spent in pet shops cannot be good for the welfare of any puppy.

Puppy owners in this survey also appear to have been either unaware or unclear where they could complain if their puppy had problems. 72% took no action, while others typically complained to the KC, Local Authority, Trading Standards or the RSPCA. With this range of reporting, it would probably be very difficult to identify recurring issues from particular sellers. More than half the owners who had problems found their seller to be “very helpful” and only 6% said they were “completely unhelpful”.

Did these buyers learn any lessons?

More than half the buyers claimed they would do nothing differently and it would be really useful to know how this differed, if at all, between new owners and those who had previously owned a dog.

Surprisingly, nearly one third said that, next time, they would rehome from a rescue centre. This perhaps suggests they are looking for some degree of certainty about who the seller is, but they may not have considered why a dog might be in rescue in the first place. It’s certainly debatable whether there are sufficient dogs in rescue to meet this potential level of demand.

The other main lessons learnt were: visit the puppy at least twice before purchase, see the puppy interact with its mother, request health test results, ask more questions and do an online search for the seller’s name. It strikes me that if we could achieve this combination of buying behaviours it could make a significant difference to the puppy-buying process and would make it significantly more difficult for high-volume, poor-welfare breeders to continue their trade.

Next steps: See Mum Twice!

The report suggests that further analysis of the responses will be carried out and acknowledges that more data is needed on the behaviours and experiences of first-time puppy buyers. Both of these will, I’m sure, be helpful.

The current licensing and inspection system is clearly flawed and failing, but the chances of politicians addressing this anytime soon seem remote.

I’ve said before “if you wait for the perfect set of data, you’ll wait a very long time” and there are certainly some actions that can be taken quickly to help nudge buyers in the right direction and to make it more difficult for low-welfare sellers to get away with it. “See Mum twice” could be a key message that has the potential to make a big difference.

Download The Great British Puppy Survey 2016


[Originally published in Our Dogs: Author Ian J Seath]

What’s the point of a Breed Health Survey?

The following is an edited version of an article by Ian Seath, first published in Our Dogs.

A few weeks ahead of Crufts, the KC published an overall pedigree breed summary report and breed-specific reports from its health survey which was originally conducted at the end of 2014.

The 2014 survey’s stated aim was to find the most prevalent conditions currently affecting live dogs and the most common causes of death and reasons for euthanasia.

The KC’s press release also identified other benefits arising from the survey: “These results give an idea of where progress has been made, where it still needs to be made, and how it is best to make appropriate changes”.

This was the largest survey of its kind, promoted to 385,000 owners of Kennel Club registered dogs, from 215 Kennel Club recognised dog breeds. It resulted in responses covering 43,207 live dogs and deaths of 5684 dogs, compared with 2004 survey responses for 36,006 live dogs and 15,881 deaths.

Why sampling really matters, or does sampling matter?

The sampling approaches were different in 2004 and 2014, so it’s not surprising that the response rates were also different: 24% in 2004 and 11% in 2014. I know some Breeds were disappointed with their response rates in 2004, but actually, for a paper-based survey issued via Breed Clubs, the overall response was pretty good. According to the 2004 survey report, approximately 57,000 forms were posted out (although the KC website says 70,000 were sent out to Breed Clubs for distribution). Herein lies another key difference between the 2004 and 2014 samples; pedigree dog owners who were members of Breed Clubs vs. pedigree dog owners with a dog registered at the KC. Those different owners will mean there are slightly different biases in the reported results and I mean “bias” from a statistical point of view when it comes to looking at the results.

Working out whether or not these response rates are “good” or “bad” really boils down to tests of statistical significance (where terms like “good” and “bad” are meaningless). People designing surveys do this sort of calculation all the time. You can even work it out for yourself with many of the free online calculators (e.g. Estimate the UK population of your chosen breed by multiplying its average age of death by your average number of annual KC registrations. For Dachshunds, that gives us a current population of about 65,000 UK registered Dachshunds. With 789 reports on live Dachshunds in 2014 we can calculate how confident we can be in the results and a margin of error. Each breed should look at their response rates and make their own, informed, decisions.

Does the person on the Clapham Omnibus care about sampling?

The simple answer is no. He, or she, if they are in the slightest bit interested in the health of pedigree dogs, would probably only want to know the answers to three questions:

  • what are the biggest health issues in any particular breed (because I own one or might want to own one)?
  • how long can I expect my pedigree dog to live?
  • have things got better, or worse, in the 10 years between the two KC surveys?

Every breed that has a KC report can look at the data and clearly see what the most frequently reported health issues are. If you’re unlucky (or lucky, depending on your perspective!), there will be so few reports that you can’t find priority issues. For example, in Smooth Dachshunds the report shows 18 different conditions, each of which had just one report. In Long-haired Dachshunds, the KC report tells us there were 19 conditions reported, but not how many dogs affected by each. In these cases, there are simply too few reports to be of much use and breed surveys from 2012 and 2015 had more responses and gave more insights.

You do, however, have to look a bit more carefully because of the way some responses have been categorised. For example, in Mini Smooth Dachshunds there are reports of “Hypersensitivity (allergic) skin disorder”, “Dermatitis”, “Pyoderma”, “Chronic Itching” and “Unspecified Skin, Ear or Coat”. Individually, the highest has a prevalence of just under 4%, but cumulatively, they account for nearly 13% of disease prevalence and this is actually higher than the reports of IVDD (back disease). Skin problems are notoriously difficult to diagnose and resolve and, in some cases, may be due to underlying issues such as Autoimmune disease which may be a consequence of inbreeding, or Immunosuppression caused by certain medications or other illnesses.

It’s not just disease frequency; impact matters too

Just because a particular health condition comes out as being most prevalent, doesn’t mean it’s the one that has the highest welfare impact on the dogs at the individual and the breed level. A condition that has a low prevalence currently, might have the potential to have a serious impact on the breed in the longer term. For example, if it is known to have a recessive mode of inheritance, there may already be a high Carrier frequency in the breed.

We also need to consider age of onset. Like people, all dogs are going to be ill with something, at some time. Many breeds will have reports showing cardiac conditions; Heart Murmurs had an overall prevalence of 0.9% in the 2014 survey, but without knowing their age of onset, progression and prognosis we are missing lots of useful information. Any early onset condition that results in “early death” is clearly of more significance to owners than a late onset condition where death “due to old age” might be reported.

Age of diagnosis (which may not be the same as onset) is reported in the KC’s overall and breed reports. It’s presented in the form of the visually confusing “Box and Whisker” plots, but once again, breeds do have the opportunity to look more deeply into the health conditions being reported. In the overall data there aren’t many surprises: food allergies, itchy skin, elbow dysplasia all show up early (on average). Cancers and tumours show up later in life (on average). Since skin conditions do not appear as a high frequency cause of death, unlike cancers, we might conclude that many dogs may be suffering these conditions for most of their lives, with or without effective treatment.

The person on the Clapham Omnibus may also be wondering if his/her chosen pedigree breed is more likely to suffer from a particular condition than a different breed, or from pedigree dogs in general.

Breed Clubs can answer that question quite easily using a statistical technique called the Odds Ratio. This has been used extensively to report data from the VetCompass studies. It lets you test, for example, whether the 3% prevalence of Heart Murmurs in breed X is statistically significantly different from the 0.9% prevalence across the whole 2014 survey sample for all breeds. We’ve been able to use the Odds Ratio to confirm the higher rate of epilepsy in Mini Long Dachshunds (which we already knew about) as well as skin conditions in several of the Dachshund varieties (which we didn’t previously know about).

What exactly is “old age”?

Even with the smaller number of deaths reported in 2014 compared with 2004, the KC is able to report the Median age of death overall for pedigree dogs (10 vs. 11.25) and the numbers are also presented within the Breed Reports.

They also report age of death and cause of death using more Box and Whisker charts. There is a wide range of “old age” age of death reports, with 95% ranging from 8-19 years old. This is not surprising because we know that “old age” is different in big dogs and small dogs. There’s plenty of research being done on this, including an epigenetics project which the AHT is participating in and using Miniature Longhaired Dachshunds as their model for a breed with high longevity.

If you’re lucky, your Breed Report will also have an Age of Death Histogram. This shows how many dogs were reported to have died at each age from under one, in one year increments, to whatever the oldest dog was. Looking at the shape of this histogram can be useful. The highest point tells you the age when most of the dogs died; it’s not necessarily the average (Mean) age unless the distribution is perfectly symmetrical.

So, are things better or worse after 10 years?

This is the question Jemima Harrison leapt to answer on her blog shortly after the KC published its results, proclaiming an “apocalyptic drop in purebred dog longevity”. It’s an entirely predictable question given the “10 years on” dimension of the 2014 survey. However, on the basis of the results reported, it can’t be answered; at least not with any statistical confidence. So, we’re left with “apocalypse now” headlines, cherry-picked to make a point.

Not only can’t you tell if average age of death has reduced, but it’s hard to make comparisons at the level of individual health conditions. So, in Dachshunds, in the 2004 survey, IVDD was categorised in the same group as Epilepsy as a “Neurological condition”. We have nothing we can directly compare between 2004 and 2014 unless there is some way of revisiting the source data for conditions reported in 2004.

In Dachshunds, there are now three sets of data to help make comparisons at the level of individual health conditions; the KC’s 2014 results and breed surveys from 2012 and 2015. However, 3 years isn’t enough to expect to see any meaningful changes in prevalence.

What exactly is the point of Breed Health Surveys?

The “point” of Breed Health Surveys depends totally on “the exam question” you are setting out to answer. If the exam question is “what’s the biggest issue?”, most Breed Clubs’ surveys have been able to answer that. The KC’s latest survey does too.

If you want to know where to focus effort on improvement, asking about prevalence and age of diagnosis isn’t going to get you very far. You need to know about severity and welfare impact as well.

Finally, if you want to know if there’s been any change (for the better or worse) over a period of time, you’d better make sure you’re measuring the same thing, in the same way, at the start and the end. Otherwise, you’ll end up with “Garbage in, Gospel out” with someone cherry-picking the results to suit their own argument!

The approach in Dachshunds has been to answer very specific “exam questions” in each survey and I am convinced that Breed Clubs are best placed to do this sort of work. The KC’s 2004 survey results provided a fantastic platform for breeds to use to shape their own future work. The challenge is that far too many of them don’t have the capability or the capacity to do what’s needed, even if they have the motivation and desire.

I’ve written before about the value of large-scale epidemiological studies such as the VetCompass Project. Yes, there are coding and classification challenges with “dirty data”, but the data set is already massive and continues to grow. Last year it had around 2 million unique dogs in the database, from over 450 veterinary practices. This resource is only going to get more useful, but I suspect the biggest constraint to its value will be the available resources to mine and analyse the data.

One other thing VetCompass does really well is communications; it publishes open-access peer-reviewed papers that meet the needs of a technical audience, with supporting data available. It also publishes infographics; easily digestible summaries that are visually appealing and comprehensible to the “person on the Clapham Omnibus”. VetCompass seems to practice a very “agile” approach to the use of its data assets. It publishes useful chunks of information at frequent intervals, that answer specific questions. We’ve tried a similar agile approach with our Dachshund Breed Surveys; feeding people results and insights as soon as we can. This helps people see the value of their inputs quickly and repeatedly, so they are more likely to support future initiatives.

VetCompass gives us “big data”; breed health surveys give us “small data”. We need both, but most importantly, we need to define the “exam questions” before rushing off to design surveys, or to see if we have data already available.

The gene genie is truly out of the bottle

Recently, I’ve had some fascinating conversations with canine geneticists about emerging technologies and upcoming research projects.

It seems that it is now possible to identify new, simple recessive mutations from the DNA of a single affected dog. Not long ago, laboratories like Cathryn Mellersh’s at the AHT would typically be asking Breed Clubs to come up with cheek swab samples from 50 affected and 50 unaffected animals. For many breeds, that was probably quite a challenge and virtually impossible in the numerically small breeds. Back in the days when the AHT was looking for the mutation that caused PRA in Miniature Longhaired Dachshunds, they even had to have their own research colony of dogs. By the way, “back in the days” is just over 10 years ago.

I was told of an example where a new genetic mutation that causes a painful eye condition has been identified in a particular breed and a new DNA test can be offered to breeders. There have only ever been a couple of clinical cases reported. That may be because it is incredibly rare in the breed population, or perhaps it simply goes undiagnosed or unrecognised during BVA/KC/ISDS eye examinations. This is a breed where several other DNA tests are already available for eye conditions and breeders are expected to make use of other available screening programmes for hips and elbows.

Should the breeders be encouraged to use the new test? Should the Breed Clubs carry out a research screening exercise on a suitably random, but statistically significant, sample number of dogs? Should DNA samples that have been submitted for the other eye conditions be re-screened for the new mutation?

One danger is that breeders will find themselves faced with yet more expense; the good breeders will want to do the right thing and the bad breeders will carry on regardless (and make a bigger “profit” on the sale of their puppies).

The risk of not screening a suitable sample of the breed is that there is no way of knowing how high the mutation frequency is in the population. Although there may be currently very few known Affected dogs, if it turns out that there are a large number of Carriers in the population, then there is certainly a risk of more clinically affected dogs appearing in the future. If a Popular Sire is a Carrier, then there’s an even greater risk to the breed.

The other complication for many breeds comes when there are multiple tests available and any given pair of dogs in a planned mating could be Clear, Carrier or Affected for different DNA tests, plus have a range of different screening statuses for their clinical tests. Just how do you decide if it is “safe” to mate two animals together? I’m sure a number of breeds are  already finding themselves in this situation. Presumably, the use of Estimated Breeding Values and Genetic Breeding Values holds out some hope for them, but these are very dependent on having enough data available from people participating in the the various screening programmes.

Give a dog a genome

Perhaps the most exciting news in January was the AHT’s announcement that they plan to sequence the genome of 50 different breeds. They have £50,000 of funding from the KC Charitable Trust and want Breed Clubs to match this. I’m aware there has already been a flurry of activity on various breed Facebook pages to set up fundraising activities.

We already know the potential value of this type of project because a Cornell University team has performed a large, across-breed genome-wide association study (GWAS) in dogs, uncovering variants associated with everything from body size and fur traits to dog diseases such as epilepsy, cancer, and dysplasia. They have pre-empted the AHT’s project and published their results in January.

The Cornell researchers genotyped more than 4,200 dogs for the GWAS, focusing on a dozen common dog traits and diseases. The analyses included dogs from 150 breeds and 170 mixed breeds, as well as 350 village dogs from 32 countries. This is clearly on a much larger scale than the AHT plans, but their results certainly add weight to the case for the AHT looking at breeds in the UK.

For example, the researchers used data for dogs from 82 breeds — 113 cases and 633 controls — to track down two loci linked to elbow dysplasia. One locus had stronger effects on elbow dysplasia risk in Golden Retrievers and English Setters, the other showed closer ties to the trait in Labrador Retrievers and German Shepherds. Along with the across-breed analyses, the team did several within-breed association studies, including a lymphoma analysis in Golden Retrievers, a search for idiopathic epilepsy in Irish Wolfhounds, and a Boxer-centered analysis of granulomatous colitis.

We need to be clear though; these are not “DNA tests” for these particular conditions, but they are an important finding not only for canine health, but also for helping to understand similar complex diseases in people. This ties closely to the increasingly common messages about “one medicine” that many people will have heard Professor Noel Fitzpatrick speak about on his SuperVet TV programmes. Noel’s work on treating canine patients is attracting attention among human surgeons and there are, no doubt, many more potential examples where veterinary and human medicine and surgery can learn from each other.

One medicine

One of the earliest examples of that cooperation and learning was the search for the Lafora gene in Miniature Wirehaired Dachshunds. Nearly 15 years ago Dr. Berge Minassian from the SickKids Hospital in Toronto visited owners of Mini Wires in the UK and began a collaboration that led to the discovery of the gene and mutation which causes Lafora.

Lafora Disease is a late-onset myoclonic form of epilepsy that affects humans and dogs. In people, the disease, which is progressive, usually results in death in the teenage years. In Miniature Wirehaired Dachshunds, just under 10% of UK dogs have been identified as Affected by the DNA test that Dr. Minassian’s team developed.

In January, he returned to the UK to seek their support in the development of a therapy which has been shown to be effective in mice and which, it is hoped, will benefit humans and dogs. The Wirehaired Dachshund Club’s Lafora Team will be working with Berge and Dr. Clare Rusbridge to recruit a group of clinically affected Mini Wires, plus a control group of dogs, to run the trial with the new therapy over a 2 year period once funding and ethical approvals have been confirmed.

This could be a landmark moment in what is a unique collaboration between breeders, veterinary medicine and human medicine. The potential to develop a viable therapy for Lafora Disease would be life-changing, both for the people affected by the disease and for affected dogs.

The gene genie is truly out of the bottle and it opens up opportunities to benefit people and dogs that could barely have been imagined just a few years ago.

It’s a dog’s life: When O.R. meets Canine Welfare

Inside OR 0415The April 2015 edition of “Inside OR”, (The Operational Research Society’s Newsletter) contains an article by Alessandro Arbib on the UK Dog Modelling project we have previously blogged about.  Alessandro is a member of the DECC OR team that carried out this pro bono project on behalf of the RSPCA and Dog-ED.

You can download a copy of the article here: Dogs – Inside OR 0415.

Health testing: time to see the bigger picture?

This article was first published in Our Dogs as part of Ian Seath’s “Best of Health” series.

The latest edition of the KC sponsored Journal of Canine Genetics and Epidemiology has a paper by researchers from the Roslin Institute in Edinburgh.  “The challenges of pedigree dog health: approaches to combating inherited disease” is one of the best papers I’ve read for a long time.  This is an open-access paper, so anyone can read the full paper. []

The review discusses the background to inherited genetic diseases in pedigree dogs and how breeding strategies and genetic testing can be helpful in combating and reducing disease frequency. It also highlights the importance of maintaining genetic diversity within each breed. The strengths and weaknesses of the various approaches to health improvement such are also discussed.

The loss of genetic diversity in pedigree dogs has been caused partly by breeding practices such as line-breeding, over-concentration on certain physical traits and over-use of so-called popular sires.  Interestingly, the paper says that loss of diversity and inbreeding does not always mean an increased incidence of poor health.  The authors suggest this might be because current inbreeding hasn’t depressed genetic variation significantly from the “genetic load” present in the founding population, or harmful recessives may actually have been bred out.

Health conditions not related directly to Breed Standards account for over 75% of all inherited conditions in dogs according to a 2010 paper by Asher et al.  That rather makes a nonsense of the calls being made by the RSPCA for Breed Standards to be overhauled and reviewed by an independent authority.  The increasing prevalence of diseases is more likely to be a result of the way breeds have developed, i.e. breeding practices, than Breed Standards themselves.

Farrell et al in the Roslin Institute paper says that clearly a relationship exists between morphologies and diseases; we only have to look at the brachycephalic breeds to recognise this. But, directly apportioning the contribution of “shape” to the prevalence and severity of health issues is not straightforward.

As an example from my own breed, Dachshunds, we are currently conducting a “lifestyle” survey where we are gathering data on the length and height of dogs as well as information on their diets and exercise.  The emerging data (from 1700 dogs) show 16% have had some degree of back disease, but the prevalence varies from 8% in Standard Wires to 24% in Standard Smooths. I’ve not yet analysed the body proportions or weights for each variety of Dachshund, but the average length to height ratio across all 1700 dogs is exactly 2:1, which just happens to be what our Breed Standard specifies.  It will be fascinating to see if we can find a correlation between body proportions and back disease from this large sample of dogs, and to compare our findings with those of Rowena Packer who published a paper on this subject in 2013.  She concluded that longer, lower Dachshunds had a higher risk of back disease.

Farrell et al go on to say that 396 disorders have been identified in pedigree dogs that are known, or suspected to have a genetic root cause.  They don’t explain the prevalence of these, nor do they describe their severity/impact on a dog’s wellbeing.  They go on to describe the importance of screening schemes and the increasing availability of DNA tests.  Some screening schemes have yet to be successful or are, at best, making slow progress towards improvements.

A further insightful piece of analysis of the Farrell data has been done by Dr. Carol Beuchat of the Institute of Canine Biology.  She looked at the raw data supporting the Farrell paper and showed that 47 breeds have more than 20 identified genetic disorders. GSDs top the list with 77, closely followed by Boxers with 63.  However, there are only tests for 11 of the GSD disorders and only 4 for those in Boxers.  The stark conclusion from this is that there is a huge gap between genetic problems and available DNA tests and even if there was a test for every issue, breeders simply could not afford to use every one and what on earth could they do if they had all these results?

What is more worrying is that, while there are only a few tests available, but many more inherited diseases, breeders may be making things worse by removing dogs from the gene pool on the basis of a single DNA test.  Removing all “Affected” dogs for a particular condition risks increasing the frequency of other harmful recessive mutations.  Not only that, but removing dogs from the gene pool further reduces the Effective Population Size with its associated risks of more inbreeding and genetic bottlenecks (especially if everyone rushes to use a popular “Clear” stud dog).

Carol Beuchat says “A health-tested puppy with a Coefficient of Inbreeding of 30% is an oxymoron. Preventing the 25% risk of a known disorder, then breeding with a 30% risk of producing a new one is not a responsible breeding strategy“.

Health-testing is doomed to fail as there will never be tests for all the mutations and using tests to remove dogs from the gene pool will make things much worse.  We’d probably make more progress by discouraging “popular sires” than seeking the next generation of DNA tests.

I think much of what the Farrell paper says completely overturns what so many people are saying they want the KC to do, such as only register puppies from health-tested litters and make health-testing mandatory.  Do they mean “every possible health test” now and in the future? Yes, health-testing is important and should certainly be used to avoid producing puppies that will be “Affected” by serious health conditions.

Screening schemes and DNA tests are valuable tools available to breeders, but they are not “the answer” and must be seen in the wider context of effective breeding strategies.  As with the “events, dear boy” at Crufts, health tests are simply events and we mustn’t lose sight of the bigger picture.

Note: Carol Beuchat’s ICB blog post which builds on the Farrell paper is worth reading: