There’s been a lot of discussion in the worldwide Irish Wolfhound community on the popular sire syndrome, especially related to Quincy of Kilmara, his parents and siblings.

The popular sire syndrome is usually used to describe the situation where one stud dog and his offspring has become so popular that it’s very hard or impossible to avoid him in any given pedigree or mating. Most or all dogs alive will be related to him in some way. This constitutes a genetic bottleneck, where this dog’s genes are spread throughout the whole worldwide population.

Historic popular sires

There’s been a number of popular sires in Irish Wolfhound history, where some reasonably popular dogs born in the 70s now being in most pedigrees. The most well-known example of these is Eaglescrag Lysander, born in 1975. Almost all dogs born from 1999 and onwards are related to him. The last litter born without him in the pedigree was born in Canada in 2012. Other well known and historic examples are Clonboy of Ouborough and Sanctuary Rory of Kihone who both have a very special place in our breed history as important dogs around World War II. They are both present in the pedigree of every Irish Wolfhound born in the last 50 years or so.

Eaglescrag Lysander, now present in almost every pedigree of Irish Wolfhounds alive today.
The development of Eaglescrag Lysander’s influence on the breed

How do they occur?

The popular sire syndrome occurs when there’s either very few individuals to breed from, or one dog produces excellent progeny who are then used a lot. Not all dogs who produce a lot of litters will become a popular sire and some dogs do eventually become very popular through the quality of their progeny even though they didn’t breed that much.

A good example of this is our 100+ founders, who are all present in all modern Irish Wolfhound pedigrees. It’s thus impossible to breed an Irish Wolfhound without the blood from great danes, borzois, the numerous deerhounds, the one mastiff or one tibetan dog used in resurrecting the breed more than a century ago. They’ve all gone on to become involved in every Irish Wolfhound pedigree. This has occured naturally, mainly through the breed bottlenecks around World War I.

Wolf – the tibetan dog present in every Irish Wolfhound pedigree for almost 100 years

In IWDB.ORG, there’s a special tool (Under the offspring-pane) to look at the influence every dog has had historically. These graphs really show how a popular sire syndrome evolves over time. There seems to be a point-of-no-return where a dog who passes that point eventually will become a popular sire given enough time and generations. One might argue that this really won’t be a problem unless each dog is reasonably closely related to the dog in question. With Sanctuary Rory of Kihone it took only four generations before he was present in the pedigree of more than 90% of dogs being born. Thus he had a major influence because of the short timespan used to become dominant. With Eaglescrag Lysander it took six generations to reach that point. The same goes for Quincy of Kilmara who passed 90% in 2016. Others are slower in gaining influence, like Wild Eagle Saxon-StClair, born in 1980 and now approaching 90% population coverage, nine generations later.

Influence of Sanctuary Rory of Kihone
Sanctuary Rory of Kihone very quickly got a presence in every Irish Wolfhound pedigree

Some mathematics

Some would argue that the popular sire syndrome really doesn’t matter unless the sire in question is present in all 5 or 6 generation pedigrees. The tibetan hound Wolf had his first litter in 1892, some 31 generations ago. Looking at the pure mathematics of this, these 31 generations would include some 4 billion individuals. It’s extremely unlikely that any dog born at that time who had descendants over a few generations wouldn’t be present in all pedigrees today. Even if Wolf is present 4 million times in your 31 generation pedigree, he would still only have contributed 1/10 of a percent of the gene material in your dog. His influence is thus reduced through the many generations passed and the influence of other dogs.

Does it all matter?

Is the popular sire syndrome really important? Yes, it is. As a breed we need to make sure there’s a huge variation in the dogs being used in breeding. If we all use the same sires or allow them to be overused, we will lose genetic variation, be more vulnerable to genetic diseases and generally have a less diverse breed than we do today. It’s the responsibility of every breeder to take care of our breed and make sure we don’t get stuck in genetic bottlenecks. It’s also the responsibility of every owner of males to make sure they don’t become matadors. A matador is a very popular stud dog, generally used to sire more than 5% of the population in any given region. Creating matadors will increase the likelihood of him becoming dominant in pedigrees over a short period of time. Special care should be taken when semen is exported or stud-dogs are being used abroad as these may quickly be influential around the world.

Given the new tool in iwdb, breeders may see how any dog in a trial mating has influenced the breed and take appropriate action as they see fit.

Blog post written by Per Arne Flatberg