VetGen - The leader in veterinary genetic disease research and genetic disease detection services for purebred animals

Breeding Strategies

VetGen's DNA test findings can be extremely valuable when developing and implementing your breeding plans.

Interpreting Your DNA Test Results for Autosomal Recessive Diseases

There are three possible test results: Clear, Carrier, and Affected. Below is a description of what each result means to you as a breeder.


This finding indicates that the gene is not present in your dog. Therefore, when used for breeding, a Clear dog will not pass on the disease gene.


This finding indicates that one copy of the disease gene is present in your dog, but that it will not exhibit disease symptoms. Carriers will not have medical problems as a result. Dogs with Carrier status can be enjoyed without the fear of developing medical problems but will pass on the disease gene 50% of the time.


This finding indicates that two copies of the disease gene are present in the dog. Unfortunately, the dog will be medically affected by the disease. Appropriate treatment should be pursued by consulting a veterinarian.

Affected (In the case of vWD Type l**)

This finding indicates that two copies of the disease gene are present in the dog. These dogs always have a potential to bleed given the right circumstance and will always pass on the disease gene (mutation) to their progeny. Please see the following page, for more detailed information. Also, inform your veterinarian and consult with him/her regarding this test result.

** In the case of Type l vWD - All puppies will be genetically Affected (see "Notes" below).

Helpful Canine Breeding Chart

The chart provided below outlines the implications of various breeding pair combinations. Remember, it is always best to breed "Clear to Clear". If followed by all breeders, these strategies will ensure a significant reduction in the frequency of the targeted disease gene in future generations of dogs. However, to maintain a large enough pool of good breeding stock, it may be necessary for some breeders to breed "Clear" to "Carriers" (see below).

Clear Male Carrier Male Affected Male
Clear Female 100% Clear 50/50 Carrier/Clear 100% Carrier
Carrier Female 50/50 Carrier/Clear 25/50/25 Clr./Carr./Affctd. 50/50 Carrier/Affected
Affected Female 100% Carrier 50/50 Carrier/Affected 100% Affected

Ideal Breeding Pair - Puppies will not have the disease gene (neither as Carrier nor as Affected).

Breeding Is Safe - No Affected puppies will be produced. However, some or all puppies will be Carriers.Accordingly, it is recommended that Carrier dogs which are desirable for breeding be bred with Clear dogs in the future, which will produce 50% carrier and 50% clear animals, to further reduce the disease gene frequency. These offspring should be tested by VetGen's test for this defective gene, and if possible, only the clear animals in this generation should be used.

High Risk Breeding - Some puppies are likely to be Carriers and some puppies are likely to be Affected. Even though it is possible that there will be some clear puppies when breeding "Carrier to Carrier", in general, neither this type of breeding pair nor "Carrier to Affected" are recommended for breeding.

Breeding Not Recommended - All puppies will be genetically and medically affected.


  1. The breeds who have vWD Type 1 and where a DNA test is currently available are:
    Bernese Mountain Dog, Coton de Tulear, Doberman Pincher, Drentsche Patrijschond, German Pinscher, Kerry Blue Terrier, Manchester Terrier, Papillon, Pembroke Welsh Corgi, Poodle and Stabyhoun.
  2. The breeds who have vWD Type ll and where a DNA test is currently available are:
    Chinese Crested, Collie, Deutsch Drahthaar, German Longhaired Pointe, German Shorthaired Pointer, German Wirehaired Pointer, Pointer
  3. The breeds who have vWD Type lll and where a DNA test is currently available are:
    Scottish Terrier, Shetland Sheepdog, and Kooikerhondje.
Canine: vWD Patents
US Patent No. 6,040,143 and 6,074,832
Licensed Exclusively by The Board of Regents of the University of Michigan (Ann Arbor, MI) System to VetGen LLC