> Slightly different:
>
> Would you criticise the offspring of a dog blind from PRA (when it was not possible to know the parents were carriers) possessing outstanding characteristics being used to preserve it's positive traits by being mated to a clear partner once a DNA test becomes available, and thereby being able to breed the 'unaffected' and healthy carrier offspring to clear partners to obtain some clear offspring to continue with and be clear of the mutation?
No, I wouldn't, because it WASN'T possible to know the dog would go blind. But to deliberately breed KNOWING you will/may produce a dog blind and deaf from birth
and then using it at stud churns my stomach.
I have bred small animals - cavies (guinea pigs) and hamsters both have a Roan gene which behaves very similarly to Merle, in that breeding two Roans together (in either species) can and will produce micropthalmic or anopthalmic whites - animals born smaller and weaker, pure white, and with either completely missing or abnormally tiny eyes.
I've always had a gripe that some pet stores (and one major well-known chain in the case of hamsters) often have animals with this gene on sale - leaving wide open the possibility that a novice will buy two and breed them together or, as is
very common in these mass-bred factory farmed small animals, accidental pregnancies that occur may produce such offspring.
I am very very pleased our KC refuses to register merle-to-merle breedings and has refused to accept Merle as a 'new' colour in some breeds.
However that just leaves the BYBs and PFs to do as they wish, as they certainly will :( It certainly hasn't stopped the BYBs who are selling Merle Staffordshire Bull Terriers!

Dog rescues often get merle-to-merle bred litters of BCs and working sheepdogs - one would hope accidental, but who can say for sure?