 |
| Author | Post |
|---|
Aaron
DWNA Member
|
Posted: Thu Feb 12th, 2009 03:56 pm |
|
This was an e-mail sent to me today by John Jeanneney. He is a European wirehaired dachshund breeder and a board member of United Blood Trackers. Many of the genetic issues discussed in the below article apply directly to our Wachtelhunds.
I know many good people are interested in becoming Wachtelhund Breeders. If you are such a person, please take the time to read this article. Good breeding involves more than breeding a good dog.
Aaron
By John and Jolanta Jeanneney
1584 Helderberg Trail, Berne, NY 12023
518-872-1779, john @born-to-track.com
Beating the Gene Pool Blues
The explosion of interest in tracking dogs has brought to light a number of imported breeds never heard of by most hunting dog folks. The European wirehaired dachshunds,
quite unlike the lower, heavier American dachshunds, are one of these breeds. Another is the Bavarian Mountain Bloodhound. In the case of both of these breeds, all the dogs working in North America today number only few hundred. These dogs are either imports themselves or they are descendants of the small gene pool of imports.
There are risks involved when breeders keep on producing dogs, all from the same limited ancestry, over a number of generations. Determining these risks can get pretty complicated, but basically the risks fall into two broad categories. (1) Undesirable, even lethal, genetically based traits start building up when the bad recessive genes come together more and more frequently; (2) Inbreeding decline sets in: dogs begin to lack the stamina, size and reproductive capacity of their ancestors.
We’ll go into more detail on all this in a few paragraphs, but first let’s consider why it’s not possible to start out with good genetic stuff and then through careful selection maintain this treasure generation after generation. The model of putting gold bars in a safe deposit box for the benefit of your grandchildren just doesn’t apply here.
Here is a concrete example to illustrate the point, but I’m sure that most tree dog breeders know of similar cases. I’ve chosen a “safe” beagle example that’s unlikely to outrage anyone living today.
Sixty years ago Willet Randall’s Patch Beagles were highly regarded as tough, smart hounds that could drive a snowshoe hare from dawn far into the night. Willet lived way back in the Adirondack Mountains of New York State. Through his advertisements and his articles in Hounds and Hunting, he made it clear that he prided himself in keeping the Patch strain pure.
Patch Hounds pleased their buyers for many years. Then something happened; Willet never said just what it was, but he began out-crossing.
Years ago I had an opportunity to spend a weekend with one of Willet’s disciples who had legally taken over the Patch hounds and the Patch name as the great old codger’s life ended when he was in his 90s. On Saturday evening Ron got out the old Patch pedigrees of Willet’s later years. There was no Patch strain left except for the name! Almost every litter was an outcross, and he had reached out to use many of the popular studs of the time. I knew that the appearance of the Patch beagles was much the same, mostly white with lemon markings, but there was no concentration of the old Patch breeding left. The gold bars in Willet’s safe deposit box had turned to grey dust. Why? We will never know the details.
Willet Randall is a good example of an intelligent breeder who developed a superior strain of hounds through close line breeding and inbreeding. For quite a while it worked very well for him, but there was a limit. Very few breeders can keep things going for more than three of four dog generations, then things fall apart, and the successful breeding action moves somewhere else.
The case of imported strains or breeds of tracking dogs is a little different, but the possibilities of getting into inbreeding trouble are similar.
First there is the problem of undesirable recessives mentioned earlier. All breeds have them; these can be such things as over-bite or under-bite, undescended testicles, and a genetic form of blindness, Progressive Retinal Atrophy (PRA). Congenital heart problems and a genetic tendency to certain types of cancer at a young age are big problems too. Unstable temperaments are still another. According to experts on canine genetics each individual dog within a breed carries four or five genes for potentially fatal diseases or defects. Usually they will not affect the dog carrying them because a single gene will be insufficient to cause the problem. But when relatives are bred together, the odds that two defective genes, one from the sire and one from the dam, will be brought together increases and the frequency of the disease rises.
In a healthy breed population the occurrence of these genetic traits is low. In that same population there will be many more apparently healthy dogs that carry the recessive gene but do not have the actual defect caused by two copies of the recessive gene. But if there is a lot of inbreeding, it becomes much more likely that the “bad” genes will come together and produce defective puppies.
With small populations of imported dogs there will be genetic problems if new imports, from unrelated bloodlines, are not brought in periodically. The potential risk is there with European hunting dachshunds, with the Bavarians also mentioned, with certain versatile Continental pointing breeds, Jagdterriers and Wachtelhunds. Preventative measures must be taken by bringing new imports.
Unfortunately, the breed is not going to be healthy just because new “blood” gets imported. In spite of new imports, the gene pool may stay very small or get smaller if only a very limited number of dogs are actually used for breeding. This is especially true in case of stud dogs, which can have a much bigger impact on the breed than brood bitches. One brood bitch can have 4-5 litters in her lifetime so the number of puppies she produces is not substantial. On the other hand, there are no biological limits on how many litters a stud dog can sire in his lifetime. In some cases when a stud dog is used for breeding a great deal, he can wreak havoc on the genetic health of the breed. Remember that every dog carries unwanted recessives. Overuse of the popular sire can not only saturate the breed with a defective recessive gene, but it will also prevent other males from contributing to genetic diversity. This is not a good thing as in the future it will be very hard to breed away from a fault carried by a particular stud dog.
Individual breeders may not be aware of these potential problems. Quite often an individual breeder has a limited view of the larger picture of his breed; what is good for him, may not be good for the genetic health of the breed. A breeder may think he is producing a healthy outcross, but he may not be aware that if too many other breeders use the same stud dog the gene pool will be getting smaller and smaller. He thinks he has done his job well – he has not linebred or inbred, and the pups he has produced are very good. However, if most breeders use the same stud dog, problems will be evident in the next generation. Most individuals will be related as they will be daughters or sons of the popular sire. When these dogs are bred subsequent generations will concentrate the popular sire’s genes more and more. Defects will start becoming evident.
For this very reason some European breed and national clubs impose restrictions on how many times male dogs can be used for breeding in their lifetime. They want to prevent the narrowing of gene pools due to excessive use of a small number of sires.
Inbreeding depression, the second category of problems mentioned at the beginning of this article, is more difficult to identify, but it can be a problem in the long run. The reasons for it are not fully understood and the symptoms are not always the same. But inbreeding depression arises in everything from plant breeding to horse breeding. There has been much in the news recently about excessively fine bone in certain strains of Thoroughbreds. Nervousness and a lack of toughness and thriftiness in dogs are probably signs of inbreeding depression. Males that don’t want to breed and females that produce small litters are often a consequence of inbreeding depression as well.
Two years ago it looked as if we were headed for trouble in the European type of wirehaired dachshund used for tracking big game. Most of the dachshunds working were siblings or first cousins. Backyard breeders, attracted by the sales opportunities, were getting into the action with no idea of pedigrees, and no idea of what is needed in a good tracking dog.
I’m happy to report that in the last two years several unrelated or remotely related puppies have come into the United States. Cameron Cruse of Neosho in western Missouri and Bob Hageman in Gainsville, New York, have acquired what appear so far to be good males. Ed and Barbie Wills from New Hampshire and Andy Bensing from Pennsylvania imported two females.
I just got back home from a fast trip to Germany with two more young pups. Tom von Linteler-Forst is of Swedish and German breeding. On paper and at puppy play on deer liver drags he looks good. Joeri vom Nonnenschlag is also a calm, laid-back pup with lots of desire for nose work. We will see. We have learned the hard, expensive way that not all pups imported from Europe turn out well and are of breeding quality.
The Bavarian Bloodhound folks are very aware of the risks of inbreeding too. Ken Parker in Williamson, Georgia is the leader of the Bavarian network. He is giving good advice to a growing number of new Bavarian owners.
|
Dave P.
Administrator\Breeder
|
Posted: Thu Feb 12th, 2009 06:47 pm |
|
Aaron,
Many good points in this article. One reason why VDW andour DWNA breeding rules require pre-approvals on breeding. It gives us a chance to look for Coeffeicients of Inbreeding (COI). The BreedMate program that we have for the DWNA provides COIs. I have helped a number of DW owners select breeding partners on this basis. For instance, I will be breeding Bell vom Flint Hills (COI 0.390625%) with Quito Vom Morretal (COI 0.0488281%) again this year. Last year they produced Kelly Vom Eagle River (COI ) 0.0%. The COI goes up with the number common ansectors and or blood lines.
____________________
Dave Pepe
DWNA Chairman
http://www.wachtelhund.us
http://www.deutscherwachtelhund.org
|
Aaron
DWNA Member
|
Posted: Thu Feb 12th, 2009 07:15 pm |
|
Dave,
I know that you are on top of this. And that the time and $ you have spent on getting German imports to the US is specifically to diversify the gene pool. It is however important that those interested in breeding understand why we are vigilant and insistent of controlled breeding.
Real world examples of what can go wrong in breeding are important reference for all of us who wish to better our breed.
Certainly the breeder should be concerned about the COI % for his specific breeding. But, on a larger scale, a good breeder is thinking of not just his line. He or She should also consider the genetic diversity of the NA Wachtel gene pool and factor this in to the planed breeding. As in the example of using one stud for numerous breedings. A stud dog may be an outstanding representative, but how many litters should he father? At what point will his good genes begin to narrow the genetic diversity and cease benefiting the breed as a whole?
I am not suggesting that any member of DWNA is doing sloppy breeding. I do think however that those interested in breeding need to understand these genetic principals. And that Club Regulation be they good, are not the only factors to consider in a planed breeding.
AaronLast edited on Thu Feb 12th, 2009 07:35 pm by Aaron
|
Dave P.
Administrator\Breeder
|
Posted: Thu Feb 12th, 2009 07:33 pm |
|
| Aaron, you are correct. My comment was more for the general Wachtelhund ownership.
____________________
Dave Pepe
DWNA Chairman
http://www.wachtelhund.us
http://www.deutscherwachtelhund.org
|
Current time is 05:40 pm | |
|
|
|
|
