I've said before that I think the partis are lovely dogs so I hope you all know I didn't post to bash anyone. It is true that partis with more color don't seem to have the problem with deafness; it's mainly the ones with a lot of white, especially on the head. It may not become a problem with the Biewers as they have more color but with the parti it is more random. I think there lies the real chance for problems. Who's to say how the pattern will evolve over several generations? With the (standard) Yorkie, there is no chance for deafness from this cause as it has no white so, in that sense, a risk is being added that wasn't there before. The piebald effect has been observed in many breeds and the mechanism for deafness is understood so taking what is known from other breeds will possibly help you to avoid the problems with the extreme piebald effect. It does seem like breed clubs disapprove of this type of breeding even with the knowledge of the cause and effect. Maybe because avoiding the problems is easier said than done? Whether parti breeders can avoid the extreme piebalds remains to be seen. While deafness is the most observable result, there are other negative effects (skin problems and shortened lifespans) that may affect the lives of extreme piebald pups. There is good info available so maybe you can use it to your benefit. From what I've read, those that do breed piebalds frequently have CERF and BAER testing done. These tests may be good tools to use in your breeding program. While it isn't a certainty that any of you will produce deaf puppies, it definitely is a possibility that should be cause for concern. |