Popular Sires - Dog World Poll results (Sept. 2013)

Post date: Oct 07, 2013 6:7:11 PM

In a recent Dog World on-line poll (6/9/13) nearly 80% of respondents said they thought the number of litters sired by any one stud dog should be limited, depending on the numerical strength of the breed. Of course, the two follow-on questions from this are:

• • What should the limit be?

  • What is the numeric strength of the breed?

The answer to the first question will always be up for debate and it may be difficult to reach a consensus within a breed. However, for owners of stud dogs it's now easy to find out what will be the impact on the breed's genetic diversity of allowing your dog to be used. The KC's Mate Select allows you to predict the Coefficient of Inbreeding of puppies from a proposed mating. If the predicted Coefficient of Inbreeding is lower than the current Breed Average COI, the mating will contribute to reducing the breed's average, which is a good thing to aim for. If the result is higher than the Breed Average COI, it will increase the breed average and make it more difficult to retain genetic diversity in the breed. Mate Select also tells us what the current Breed Average COI values are, so it's easy to compare a proposed mating with the breed average.

The second question isn't so easy to answer as the KC has not yet published the Effective Population Size data for each variety of Dachshund. The Health Sub-committee has been given access to the analyses carried out so far, which show EPS for the standard varieties in the range 30-45 and 65-75 for the Miniatures. Effective population size is the number of individuals in a population who contribute offspring to the next generation. Generally, the more inbred a population is, the lower its EPS will be as there are fewer unique individuals contributing to the next generation. These results are pretty much in line with data from other breeds that have been published previously, where small numbers of registrations typically have low EPS values. Generally, geneticists like to see an effective population size greater than 100, and judge those at less than 50 to be at risk of the effects of rapidly declining genetic diversity.

On this evidence, it would seem the people who voted in the Dog World poll have got it right and have recognised the potential risks to a breed where a few stud dogs are bred from frequently.

There are articles on the Genetics and Diversity page of the Breed Council's Health website about the so-called "Popular Sire Syndrome" and there is plenty of evidence to make it clear that high-levels of inbreeding and reductions in genetic diversity are a risky path for any pedigree breed.