Understanding breeding to prevent vWD
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).
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 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