I've been thinking about it for a while and struggling to put it in a coherent way. There are some people in Pyrshep world who are very concerned about getting "proper" colours. Such people would comment on puppy pictures: "Oh, very cute, such a shame it's a fawn merle" or "But it's not an accepted colour", or would even say how breeding fawn to merle is irresponsible and in the extreme cases would even say that it's the destroying the breed.
Now, let me get some facts straight:
1. Fawn merle looks like this as a puppy:
and might look like this as an adult:
2. Brego and his sister looked like this, when they were puppies:
Both of them look a bit brownish (there is a hypothesis that there is some modyfying gene which causes the fawn to shine through the dominant black), so I read my fair share of comments of breeding " fawn merles and not according to the standard", but the difference with a fawn merle puppy is clearly visible.
now they look like this:
BTW, Brego was shown and judged even by the president of RACP at the club show, he never got anything less than "excellent".
3. Fawn merle happens and will happen, since fawn is recessive to black and can go through generations without expressing itself. Yes, you can get fawn merle out of blue merle x black breedings (as in case of Brego's puppies). I've seen litters with fawn merle puppies where the fawn ancestors were like three or four generations away. So it's not just the question of avoiding fawn to blue merle breedings - actually if you wanted to eliminate the risk completely, you would have to genetically test the parents and make sure that at least one of them is homozygotous for black (that is, doesn't carry fawn). Both parents need to pass the fawn gene to the puppy for it to look fawn and in order to be a fawn merle, one of those parents would also have to pass the merle gene.
4. Fawn merle used to be completely legitimate colour, accepted by the standard not so long ago.
5. Fawn merle in itself is not connected with health issues or at least no more than blue merle (for instance, if the dog has blue eyes, they might be more sensitive to sunshine).
6. The rationale for excluding fawn merles from breeding was that as you can see on the photos above, the long haired fawn merle dog as an adult looks just like a fawn dog and that in turn might mean that you might not know it's a merle dog and accidentally breed it to another merle dog, which might produce double merle puppies. Now, double merle (or a dog that is homozygotous for dominant merle gene) is indeed connected with risk of getting puppies who are deaf or have eye deformities. So breeding merle to merle dogs should be avoided (the whole matter is a bit more complicated as there seem to be more variations of the M gene that just m (non merle) or M (merle), but for the sake of clarity I won't go into this right now, especially that there is an ongoing research on this topic).
But does it mean we should eliminate fawn merles from breeding?
I don't think so.
Why? Because there is a genetic test available and you can always test the dog for merle gene in case of any doubts. You could theoretically mate a fawn merle bitch with a homozygotous black dog and get only black and blue merle puppies if you wanted to.
Moreover, the gene pool in the breed is limited as it is. Why on Earth exclude any animal just on the basis of colour? There are so many other things to be concerned about - the health tests, the structure, the character, the drive, the type...
Remember, a Pyrenean shepherd is supposed to be a working dog. I haven't heard of a dog being fawn merle and that stopping him or her from being a good shepherd, good agility dog or fabulous companion dog.
If something is destroying the breed is neglecting to do proper health tests, it's breeding same combinations over and over again, it's breeding closely related dogs together, it's limiting the already small gene pool even further, it's breeding for colour rather than health, character, type, good structure and working ability.
I'm not saying we should ignore the colour genetics compeletely, I'm saying it should be LAST on the breeder's list of priorities.
What I think should be done is that the breeders insist that the standard is changed back so it accepts fawn merles again.
Remember, they are going to be born anyway. Remember, if someone is irresponsible or ignorant, nothing will stop them from breeding merle to merle, same as nothing stops some breeders from using dogs with extreme sound sensivity, fearful, dysplastic, epileptic etc (ALL of which I consider MUCH MORE SERIOUS problems than getting colours which are not according to a current standard).
If you're interested in dog coat colour genetics, there is an excellent website on this subject.
Thanks to Virginie de Andrea, the translation of the above post into French is available HERE.
Thanks to Virginie de Andrea, the translation of the above post into French is available HERE.