Colour Dilution Alopecia – not so simple!

In the last week of April, I had the pleasure of chairing another of The Kennel Club’s webinars, organised by the Health Team. It was a free webinar for owners and breeders who wanted to find out more about the dangers of breeding for fashionable colours, using the example of colour dilution alopecia – including what research has told us to date, and how best to support dogs affected with this condition.

Colour Dilution Alopecia (CDA) is a genetic condition found in some breeds that causes hair thinning and loss, which can leave the skin prone to sunburn, infection and dermatitis. The condition is associated with dogs who have a “dilute” colour (e.g. blue, lilac, isabella or silver). While the disorder is commonly described in Dachshunds and Dobermanns, it has also been recognised in other breeds. With the rise in popularity of “fashionable” coloured dogs, it’s crucial to understand the dangers that can be associated with breeding for certain colours and what breeders can do to try to reduce the prevalence of conditions associated with dilute coat colours.

My introduction to the webinar shared some data on the 2021 registration statistics of those breeds where there are Non Breed Standard (NBS) colours in their registration options. This applies to about 10% of the KC’s registered breeds. At one extreme, French Bulldogs had 70% of their 2021 registrations as NBS and 53% for Bulldogs. Labradors had 1% NBS but, with over 61,000 registrations, that still amounts to over 800 NBS dogs.

Colour Dilution Alopecia is a concern to many of us in the Dachshund community because it is reported in the dilute colours (blue and isabella). We ran a breed health survey in 2021, supported by The Kennel Club, specifically to find out how prevalent the condition was. Our 2018 survey had shown skin diseases and allergies to be the second most prevalent health concern in all colours (after IVDD – back disease) and we wanted to find out if this was a particular issue in the increasingly popular dilute colours. Most people will be aware that Mini Smooth Dachshunds have grown in popularity over recent years (under 3000 registered in 2013 and over 15000 registered last year). Shockingly, registrations of dilute Mini Smooths have grown from 0.1% in 2018 to 20% last year. Not only has the breed become extremely fashionable, but “rare” colours have too (often aided by the influence of social media).

In Fitch Daglish’s 1952 book “The Dachshund”, he refers to blue dachshunds, so it is clear that the dilution gene has been in the breed for a very long time. This is not something that has been added by cross-breeding. The high number of dilute puppies now being bred is down to intensive selection for the dilute coat colour in the UK population. Our 2021 health survey showed 80% of blue dachshunds were affected by CDA and 86% of isabellas.

Dr Rosario Cerundolo (Head of Dermatology at Dick White Referrals) presented during the webinar on the signs, diagnosis and treatment of CDA. He showed examples of the condition in several breeds, including Dalmatians, Russian Toy Terriers and Dachshunds. Electron microscope images illustrated the structure of hairs in dilute dogs that causes patches of hair thinning or loss and may also include flaky and/or itchy skin. It is an early-onset, lifelong condition, often being seen from around 6 months of age and cannot be cured; it can only be managed. 

The genetics of CDA

Dr Joanna Ilska (KC Genetics Health Manager) was the second speaker at the webinar and she discussed the research evidence and genetics of CDA. While the gene variants for dilution are now known and can be identified with DNA tests, the gene (or genes) that cause CDA have not been found, to date. Joanna explained that, while dilute colour is a predisposing factor for CDA in Dachshunds, the 2 traits are not irrevocably linked. The fact that dilute colours in some other breeds do not suffer from CDA and not all blue or isabella Dachshunds do either, shows this is not a simple genetic condition. The evidence also does not support the view that other health conditions are caused by the coat colour. So, the fact that many of the dilute dogs in our 2021 survey also suffered from autoimmune conditions is more likely to be a result of close inbreeding, use of popular sires, and strong selection within a narrow population pool.

The scientific evidence on the association between colour dilution and CDA was reviewed by the veterinary and genetics specialists on the KC’s Genetics & Health Screening Dog Health Group and they recommended an educational approach rather than a ban on registration of dilute Dachshunds. This webinar was part of that educational approach. 

Recognising that where there is demand, there will be supply, Joanna stressed the dangers of breeding for “rare” colours and offered some practical advice to minimise the risks. This included carrying out all recommended health screening, breeding from dogs over the age of 2 once they were known to be unaffected by CDA, and avoiding close inbreeding and popular sires.

Discouraging “rare” colours

You may have read the recent press release on the recommendations from the NBS Colour Working Party. The Colour Watch system mentioned in their report will be one element of the KC’s approach and provides a framework for marketing and communication to puppy buyers, breeders and owners. Work is also underway as part of the KC’s strategic review to establish more effective ways within the registration system to promote well-bred puppies with breed standard colours and relevant health-tests. For several breeds, there have also been changes made to Breed Standards and to the lists of BS and NBS colours in the registration process.

How to raise awareness?

The Colour Watch system will be a key element in the KC’s approach to raising awareness of the risks of breeding for so-called rare colours and NBS colours. Several breed club communities are already producing educational materials and we have seen great examples of these at Discover Dogs and on club websites. Clearly, there is a role for breed clubs and councils, as well as the KC. 

The KC would, of course, be pleased to collaborate with breed clubs and their charities on joint campaigns that help raise awareness. One simple step would be for breed clubs to share links to this webinar and the other resources in the KC Health YouTube channel. If breed clubs are serious about protecting the health of their breed, they need to be proactive on social media. On Facebook, there are dozens of Dachshund Facebook Groups and it’s likely the same for other breeds. It is a massive task, though, and we need to address both supply and demand.

‘The greatest enemy of knowledge is not ignorance, it’s the illusion of knowledge’: Stephen Hawking 

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IPFD Dog Health Workshop on Genetic Diversity

On May 3, the International Partnership For Dogs (IPFD) hosted their second virtual workshop. Focusing on genetic diversity (primarily from a genetic tests/tools view), 60 participants – including representatives from IPFD and their partner kennel clubs, genetic test providers, breeders, and other key stakeholders – came together online to identify genetic diversity tools and resources, and to discuss priorities and actions for the benefit of all dogs. Half the attendees had been at the 2021 online workshop which discussed Genetic Test Reporting.

The distinguished panel included Prof. John Woolliams (The Roslin Institute, UK), Samantha Hauser (Embark, USA), Katy Evans (Guide Dogs, USA), Saija Tenhunen (Viking Genetics, FI), Pieter Oliehoek (Dogs Global, NL), and Sally Ricketts (University of Cambridge, UK), who shared their time and expertise with us. These speakers had provided short (YouTube) video presentations ahead of the workshop which were the pre-work for participants. These are available to IPFD website members via the Speciality Forums. The workshop was introduced by Katariina Mäki (Acting CEO, IPFD), a quantitative geneticist who previously worked at the Finnish KC.

International and collaborative genetic diversity management is important because different countries and KCs have different policies and tools available, so there is lots of learning that can be shared. Additionally, international populations of dogs/breeds could be sources of diverse genetic material and, increasingly, there are global breeding strategies being developed. 

The problem of Popular Sires

John Woolliams said that everyone talks about Coefficients of Inbreeding (COI) but KCs and breed clubs should be having conversations about what’s happening in a breed and what else can be looked at, especially rates of inbreeding. KCs should be providing simple summary statistics on genetic diversity to breed clubs. Then, of course, the clubs need to understand how to use that information. The Popular Sire effect is potentially damaging for genetic diversity so, perversely, breed clubs publishing lists of the Top 10 winning show dogs might actually be encouraging less knowledgeable breeders to use these dogs at stud and add to the problem. Another attendee commented that one of the main concerns is that the whole pedigree dog culture is traditionally focused on the single successful specimen (or kennel). How can we shift the focus to the population of the breed as a whole? The issue with Popular Sires is that breeds are sidelining other potential sires who could be contributing to the gene pool.

Most UK breeders will be familiar with the Kennel Club’s online tool for Coefficients of Inbreeding. This is based on pedigree analysis and uses all the available pedigree information behind any particular dog. Joanna Ilska, the UK KC Geneticist, said we are discussing the number of generations to use in COI calculations but will still publish full pedigree values. If KCs worked together we could fill in missing import pedigree information. The UK has seen a reduced rate of inbreeding, reported in a paper published in 2015 (Lewis et al). This is mostly due to increased imports arising from the 2012 quarantine legislation change. Joanna said that an analysis of COI after removing imported dogs from the calculations also showed a reduction in inbreeding, and this occurred after introducing the Mate Select Tool. This may suggest breeder awareness has resulted in a change of behaviour. 

What can breed clubs do?

John Woolliams said that the absolute COI value doesn’t matter and that COI will always increase in a closed gene pool (closed stud book). What matters is the rate of increase of COI. He also talked about some of the actions that breed clubs could (should?) take, for example, looking at pedigrees and average relationships (kinship) between dogs to understand how many different dogs contribute to each year’s puppies. In some countries there is a “neutering culture” where non-show puppies are sold with endorsements or contracts preventing them from being used for breeding. This too, leads to a loss of choice and genetic diversity. One of the participants commented “We, especially breeders, need to campaign that any healthy dog is a potential parent dog. By buying a purebred dog, you have become responsible for the heritage that breed constitutes.”

Jerold Bell emphasised that there are differences between pedigree COI and genomic COI. With the former, every puppy from a given mating would be calculated as having the same COI. The latter enables you to identify differences between individual puppies in a litter, because each puppy will inherit slightly different combinations of genes from their parents. Embark is one of the providers of genomic COI testing and it can sometimes be a shock for breeders to discover that their puppies’ genomic COI is significantly higher than a pedigree COI value. For example, Brenda Bonnett commented that for a sample of GSDs, genomic COI was around 40%, compared with 30% for pedigree COI. Other recent research papers have shown the same thing. Genomic testing is still relatively expensive for breeders to do, though.

Who owns the problem?

For individual breeders making decisions about their next litter, the most important generation is the potential sire and dam you have in front of you. You can’t do much about Great-great Grandparents! Calculating the COI of that potential litter when you know you’re not using the whole gene pool may be interesting but is not going to solve the problem of genetic diversity. The actual percentage of dogs bred from is small in most breeds. In Finland, they have found that only 2% of male dogs are used for breeding. Breeders should consider having more 1-time litters and avoid repeat matings. The idea of using double matings (2 stud dogs on 1 bitch) could be a way to generate a more diverse litter of puppies (who would need DNA parentage profiling).

Kennel Clubs can (and should) provide the tools and education to help manage genetic diversity within breeds, including offering the option to open stud books for appropriate cross-breeding projects. Breed clubs are best placed to look at what is happening across their breed (nationally and internationally) and should be using this information to provide advice and guidance to breeders. 

Pieter Oliehoek made a really important point early in the workshop: the focus should not be on inbreeding but on genetic diversity. Breed clubs and breeders need to understand this important difference.

Brenda Bonnett reminded the attendees that any discussions and decisions on inbreeding or genetic diversity must be considered in the overall context of dog health. Extreme phenotypes bring with them health problems. There is no point “sorting out” genetic diversity if the dogs still can’t breathe, see, move or behave normally as dogs!

Breed Health Strategies – Why? How? and What? – DKK webinar

Here are the slides from my webinar presentation for the Danish Kennel Club (December 2021).

DKK Breed Health Strategies Webinar 2021 from Dog-ED

Breed health improvement: Finding the balance

I was pleased to be invited by the Whippet Breed Council to present a webinar at the end of February as part of their current online education programme. I had to smile when it was first advertised and billed as “an evening with Ian Seath”. I couldn’t help thinking that second prize was “2 evenings with Ian Seath”. Nevertheless, over 80 people signed up to attend. The webinar was titled “Breed Health Improvement: finding the balance” and my invitation was prompted, apparently, by reading the interview Gay Robertson wrote for the Kennel Gazette.

The plan was to talk about approaches to breed health improvement and why every breed needs a health strategy. The Whippet Breed Health and Conservation Plan is still under development with the Kennel Club but there is useful data already available from previous health surveys. The challenge is knowing where it will be best for breeders to put their effort. The presentation covered areas where it might be useful to focus attention and discussed how breeders can make use of DNA tests and clinical screening programmes, as well as some of the pitfalls to be aware of. There was an opportunity for a question and answer discussion after my presentation.

Here are my slides.

An insight into brachycephalic dog health from The Kennel Club

The Kennel Club has hosted a unique webcast to discuss brachycephalic health and what can be done collaboratively to ensure a healthier future for dogs. Chaired by Kennel Club Chairman, Tony Allcock OBE, the webcast panel comprised Dr Jane Ladlow, European and Royal College Specialist in Small Animal Surgery and leading BOAS researcher; Bill Lambert, Head of Health and Welfare at the Kennel Club; and Charlotte McNamara, Health and Welfare Development Manager at the Kennel Club.

The panel discussed brachycephalic health, approaches across Europe, the need for a collaborative, evidence-based approach, including how the Respiratory Function Grading Scheme can help protect and improve the health of brachycephalic dogs now and in the future, and the importance of data collection and ongoing research into the complex Brachycephalic Obstructive Airways Syndrome (BOAS).

Further information about brachycephalic dog health, what the Kennel Club is doing and which tools and health screening is available to breeders can be found at: https://www.thekennelclub.org.uk/flatfaceddoghealth

To donate and support further research into brachycephalic dog health and BOAS, visit: https://uk.virginmoneygiving.com/charity-web/charity/displayCharityCampaignPage.action?charityCampaignUrl=BDH