Same Standard, Same Litter, Different Coats

Rough Collies and Smooth Collies have identical standards with the exception of the coat, but interestingly, both varieties can be born in the same litter. As we’re about to wade into the tall grass again, this can only mean one thing: We’re about to talk about the “G” word (genetics), so we’re counting on genetic wonks to help us out if we get in over our heads.

In Collies, the smooth coat is the dominant gene. For a dog to be Smooth, it has to carry the dominant smooth gene.

If a Collie is a rough, however,  it doesn’t carry the gene for the smooth coat; Since there’s no such thing as a recessive smooth gene, the only way for to get a Smooth Collie from a Rough Collie is to breed it to a Smooth, and that’s how Rough and Smooth Collie puppies can be born in the same litter.

Roughs cannot produce a Smooth, but the Smooths can produce Roughs since Rough is carried as a recessive gene.

Image: “Collie Floral On Green” by Flo Karp is available for purchase as a print and home decor here 

4 thoughts on “Same Standard, Same Litter, Different Coats”

  1. I do too. Am trying to understand how this can happen. Both parents are rough. Mother collie; father Australian Shepherd.

    How can this happen?

    • could be a false smooth. there are actually several different types of longhair genes, and aussies in particular can be longhair but look relatively smooth. look for any feathering (long wispy looking hairs on the legs, butt, tail, around the ears or cheeks). if your dog has any feathering at all, it’s longhair by genetics. there are also cases where genetics are “incomplete” such as with white patterns.

      genetically any dog who is SS for white, should be solid colored. However there are plenty of cases in rough collies where they are genetically SS solid colored, but have physical white patterns like an irish white (sisi). genetics can be tricky and don’t always play by the rules lol

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