March 7, 2002
 
 

MEMORANDUM

TO

Dutch Breeders Co-operation NVFR
 
 

FROM:

Dr George A. Padgett

Professor Emeritus

Department of Pathology

College of Veterinary Medicine

Michigan State University

East Lansing, MI 48864
 
 

SUBJECT: Comments on the Dutch Kennel Club Proposed Breeding Rules
 
 

This memo is in response to a request by the Dutch Breeders Co-operation NVFR that I respond to proposed changes in Dutch Kennel Club Rules, I am particularly disappointed in the proposed limitation on the number of matings that a male in a breed can produce based on the number of dogs in that breed. This also applies to the limitation on females even though it is not as restrictive.

The first thing we clearly need to understand is that dogs are purpose-bred animals. That purpose may vary depending on the breed and people involved with the dogs. The purpose may be conformation show dogs, hunters, herding dogs, tracking dogs, agility dogs, or just pets. For the most part if a dog does not fulfill its purpose (i.c. the goal of the owner/breeder), it is generally regarded as less than desirable and tends to be discriminated against. People that own and breed dogs are always searching for the animals that produce the desirable offspring (i.e., the winners) in whatever area they are interested in. When breeders find dogs (particularly males) that produce the offspring they desire, they breed them often. Such animals are often called matadors because they produce more than their 'fair share' of puppies. They are the best animals in the breed because they produce what we want.

In order for a genetic disease or defect to be maintained in a breed, the gene or genes involved in the production of these traits must be distributed in the breeding population of dogs in that breed. So the genes(s) are present in the best dogs both male and female in the breed. They are also present in equal numbers in the non-breeding population, but we never find that out about them because these animals do not get bred.

I have included in this memo a table which was constructed from surveys conducted by each of the national breed clubs for the nine breeds listed. The table includes the number of diseases reported in the breed, the frequency of the diseases reported and an estimate of the average number of defective genes which each dog in the breed has whether or not that dog is considered to be breeding stock.
 
 
 

Since matadors are well known dogs when they produce a defect, it hits the gossip mill and it is soon known throughout the breed that he produced a problem. He, like all other dogs, carries defective genes, but on the average, he will have no more defects than any other dog in the breed. So I would ask the question why is he being discriminated against. Is it better to know what defects a dog produces so you can properly breed your female? If you know what defects a dog carries for and you know what your female carries for, you can prevent disease. If you hide the genes that a dog carries by limiting the matings, then you will never be in a position to properly breed your female. We need to know what a dog produces, and we need open registries so a breeder has that information available to them.

So if the Dutch Kennel Club limits the number of matings which a dog can have, will that prevent the spread of defective genes? The answer is a clearcut NO. Every male spreads defective genes, but it is only with the matadors that we have a chance to learn what they are. Once we know what the matador carries, we can use him properly and prevent disease.

If the Dutch Kennel Club limits the number of matings which a dog can have, will it prevent the spread of the genes from that dog? The answer again is a clear cut NO.

Why won't it prevent the spread of his defective genes? I do not believe that Dutch breeders are stupid. So if they like the offspring of a matador and if those offspring are winning in whatever category the breeders are interested in, they will try to continue to produce winning dogs. Therefore, unless the breeder is very stupid indeed, they will pick offspring of the matador for breeding stock and that matador's sons will become the next set of prized dogs.

What is the genetic makeup of the offspring? On the average, they will have one-half the defects carried by the sire and one-half the defects carried by the dam, and we will have no information about what traits are being transmitted. So if a couple or so of the matador's sons are used, most, if not all, of the defective genes carried by the matador will still be spread in the general population of the breed, but we will not know for sure which ones. All we will do if we limit the number of matings a male can produce is hide the information we need to correctly breed our dogs and we will not prevent the spread of defective genes.

The last point about matadors that is important to understand is that since we

Know what diseases they produce every mating that they make is a test mating. This is true of every mating which is made by any dog, but for the most part we do not know what defective genes they carry. With matadors since they are bred across a breed we can identify the genes they carry and we know what diseases they are test mating for. So if a matador is carrying eight defective genes as an example, then every bitch he is bred to is test mated for eight separate diseases at the same time. In a breed like the Labrador that average perhaps seven puppies per litter every bitch that is bred to the matador and does not produce any of the defects he is known to carry is test mated free of those genes to 86.6%. If the bitch produces one defect, she is test mated free of the other seven at the same level.

Matadors help us to determine where genes are, but we have to have the sense to correctly use the data.

I would make a suggestion to the Dutch Kennel Club. You do not have sufficient information about genetic disease in your dogs. You do not know the number of diseases a breed has. You do not know the frequency of these diseases in any of your breeds and you do not know how many defective genes the average dog in a breed carries.

I believe this information is required so you can understand the disease situation in your dogs. Once you have that information, you will be able to tackle the problems in an orderly and reasonable manner.
.