Merle, Merle Everywhere!

The Double Merle white (DM) is a long misunderstood dog.

This animal may ONLY be produced by breeding two Merle dogs together, be they sable merle, blue merle, or any combination of the two. The presence of a merle ancestor in the pedigree DOES NOT mean that it's descendant "carries" the merle gene. The merle gene, when "carried" is almost always displayed (except in the case of the Cryptic Merle.)

The breeding of merles to each other is highly guarded against as resulting puppies may be blind, deaf, both, or have various other health defects because of the doubling of the merle gene. Only when you are a VERY knowledgeable and responsible breeder (and sometimes, not even then) should you even attempt this type of breeding. The results can be heartbreaking and you, as a breeder, pet owner, and your sheltie's best friend, must be able to handle the consequences of such a breeding.

In many cases, the breeder will not be able to tell which, if any, of the puppies are either blind, deaf, neither or both, until both eyes and ears open. Sometimes, even then, it may be extremely difficult to tell whether a pup is deaf or blind until they are taken away from their littermates, as they tend to do as the rest of the litter does.

This can be a huge heartbreak for the breeder as, if any of these problems plague the puppies, the breeder must then decide what actions to take in either finding these pups homes or having them put to sleep. (Note: The latter option is often the more humane of the two as these affected puppies have been known to be born also without eyes.)