Can anyone tell me if a blue merle rough collie bitch can be bred with a sable & white rough collie?

This could be read as quite a loaded question!!!!!!!!!!!!!!!!

I'll leave you to answer it Gail!! ;)

Hi Guest

Physically yes, of course they can be bred :-) but there are reasons why this may not be good practice.

The merle pattern needs dark pigment (black in RCs) in the coat to be visible and as sables don't always have enough of this, there is the possibility that pseudo merles could results from merle x sable breeding.  As sables are born dark the merle pattern should be obvious in the coat of young pups but later in adulthood when the shading often clears, sable merles could be mistaken for non merle and if these are then bred to merles, homozygous merle would occur at a 25% incidence.

Merle x merle breedings are not normal practice in most breeds because of the associated risks of eye and ear deformities in homozygous merle.

This excellent USA site on colour explains it in Shelties -
http://bowlingsite.mcf.com/Genetics/SableMerles.html

Julie