Dilute colour Dachshunds (Blue and Isabella) - know the health risks

Background:

In the last year there has been a significant increase in the number of dilute coloured dogs being sold in the UK. The majority are being bred by French Bulldog and English Bulldog extreme-colour breeders, many using dogs imported from the U.S.A. or Eastern Europe, presumably as the market for both has passed the peak and they see an opportunity to make significant money from 'rare' or 'coloured' dachshunds. The blue colour is a dilute of the black and tan; Isabella (also known as lilac in other breeds) is the dilute of the chocolate colour. The gene that causes the dilute colours can also cause an issue in some dogs called colour dilution alopecia (CDA), where the hair shaft is thin and weak, meaning it can drop out of the follicle and cause baldness. Because the coat is thinner than normal, the skin can also be more susceptible to infection and sunburn, which in turn may cause cancer. The breeders are applying similar techniques to those used to promote the Bulldogs. Both pups and studs are being advertised regularly via Pets4Homes and other sites, on Facebook (though the majority of Dachshund-specific groups in the UK have banned any promotion of dilutes), as well as on Instagram. The adverts often refer to isabellas as 'lilacs', or as being DNA tested as carrying blue or lilac, or tricolour (i.e. similar language to bulldog ads) and suggest that dogs are of exceptionally high quality (with nothing to back that statement up). Those that are KC registered are frequently advertised without referencing 'Colour Not Recognised' status, at a high price (anything from £2000 - £8000!).

The breeders frequently refute that there is actually any such condition as Colour Dilution Alopecia, claiming it is an outdated and discredited notion, and that dogs of standard colours are equally affected by alopecia. They argue that without recent research to demonstrate the link between dilution and alopecia, there is no reason to stop breeding dilutes, and argue that as the KC permits registration, then that is evidence that there isn't an issue! Kennel Club current position: In June 2017, the Kennel Club issued a press release confirming concern about fashionable and 'rare' colours, and made it a condition that breeders must now manually enter the colour of the puppy if the CNR option was selected. The aim is to improve the quality of data on CNR registration across all breeds, and they state that they will work with Breed Clubs to increase knowledge in the area 'once registrations have been collected for a number of months'. The release states that "special focus will be paid to four breeds that are known to have seen surges in unrecognised colours - Labradors, Pugs, French Bulldogs and Bulldogs" (is it a coincidence that it was around the same time that Frenchie breeders started moving into Dachshunds?). Full KC statement here Veterinary Research on CDA: There are a number of papers on CDA in general and a few on Dachshunds in particular, but the majority date back 10 years or more. However, the majority of articles online about CDA reference Dachshunds in the top 10 breeds most at risk (with very few referencing bulldogs). This might be behind the colour breeders' argument that it is an outdated concept. However, Professor Tosso Leeb of the Institute of Genetics in Switzerland is currently undertaking research into CDA in various breeds, with the intention of identifying genetic risk factors.

Helen Geeson, resident geneticist and colour expert on the Dachshund Breed Council's Health and Welfare sub-committee explains: "The hypothesis is that the gene occurs in more than one version and some breeds have the problem gene whereas others do not. If this hypothesis is correct (and the research is incredibly slow and not progressing rapidly), what we do know for certain is that Dachshunds do have the version that causes CDA. At the moment, there is no DNA test for CDA (there is a DNA test for the dilution gene but it cannot differentiate between the version that causes CDA and the version that doesn't). Therefore, at the moment there is no 100% safe way to breed dilute colour Dachshunds and the people who are breeding them who say they don't have CDA in their lines cannot possibly know that for certain, as they haven't been breeding Dachshunds long enough to prove it. They are relying on mainly American breeders and some in Eastern Europe, and I am not convinced I would be trusting them all". "Despite trying to educate some of these dilute breeders, they do not want to work with the Dachshund Breed Council and try to make out that it is the DBC who have the issue and do not understand the science. I guess when you want to sell puppies for a high price you need to try to convince buyers that you know more than the authorities in the breed!"

CDA Facebook Survey In Spring 2018, Gill Key, one of the Pet Advisers sitting on the DBC's Health and Welfare sub-committee, ran a simple 10-question SurveyMonkey survey on various Facebook Groups asking dilute dog owners about CDA in their dogs. 53% of respondents were from USA, reflecting the higher number of dilute dogs bred there. 36% of respondents were from the UK, the rest being from Canada, Australia and South Africa. In total, 43% of dogs were reported as showing CDA.

However, given the small number of dilute dogs currently in the UK, it is somewhat surprising how many respondents were from the UK and on further analysis, it is interesting to note that overall, 66% of respondents had either bred from their dog already or may breed from their dog. In the UK, this is even higher: 74% have either bred or may bred from their dogs and, of these, there was only one report of CDA. This, combined with the fact that many of the reports of breeding dogs without CDA were consecutive in the survey suggests that there may have been a deliberate effort to skew the results. If all dogs that have been bred from or may be bred from are excluded, 83% respondents recorded CDA in their dogs (52% if dogs that might be bred from are included). Clearly this might be biased the other way. In summary, though the survey was limited in numbers and flawed due to the potential skew by breeders with a vested interest, there appears to be a significant number of dilute dogs affected by CDA.