In short, accidental matings unbeknown to the owner can and do take place. This means that it is possible for a litter to be sired by a dog other than the one intended by the breeder. This unwitnessed mating might be one that is most undesirable for the health outcomes for the puppies. A female may also be mated by multiple sires and successfully deliver puppies sired from such a multiple mating. DNA profiling of each puppy for parentage is the only certain method to ensure (where as mentioned below, DNA tests are available) that there are no unexpected health issues.
Desirable and Undesirable Matings?
To maintain genetic diversity it is important, especially in a breed with a relatively small gene pool, not to discard carriers of recessive diseases from the breeding pool. A desirable mating is one where the health outcomes for puppies are positive. A carrier can be mated to a normal or even an affected safely, without the offspring having the potential to be afflicted for the disease. However, mating a carrier to a carrier, carrier to affected or affected to affected does have the potential to produce the disease in the puppies and these breeding combinations should be avoided and are therefore undesirable. In the case of recessive disease both parents must carry the disease for it to be produced in the puppies. One can imagine the outcome if that accidental or non witnessed mating was between two carriers. Without DNA profiling each puppy no one would be any the wiser, until that is, a puppy unexpectedly produced the symptoms. Tambuzi provides puppy buyers with proof of parentage - this ensures some certainty and confidence to puppy buyers that (where there are DNA tests available) there will be no unexpected health issues.