As coat color/patterns go, “seal” seems to be a mystery. It makes some black dogs appear brown, and some dogs look liver colored (until closer examination reveals a black line down the back, and on the dog’s legs and tail). Seal appears only in a handful of breeds, and to our knowledge, little genetic research has been conducted into it. Consequently, our knowledge of how it’s caused or which locus is responsible for it is less than what is known about other patterns and colors. Genetics is a “walk in tall weeds” for us, but we can share that current theories include suspicions that seal is either an allele on the A locus, an allele on the K locus (recessive to K, potentially something like a faulty K allele that works in a similar way to brindle), or a modifier on an unknown locus that causes the A locus to partly show through on Kk dogs. Got that?
What does seal look like? In black and white Boston Terriers, the black appears black until bright sunlight hits the coat, and then it has a reddish cast to it making it look almost brown. That said (and as far as we know), a black seal dog will always have a black nose, regardless of how brownish its coat appears.
Seal is an accepted color in the American Staffordshire Terrier and the American Hairless Terrier, but not in Bulldogs (we found one site that “specializes” in “rare” colors in the breed, including “lilac seal” that’s not an accepted color in any Bulldog standard we found). Both Alaskan Malamutes and Boston Terriers accept seal and white, and add “seal brindle and white” to the list of Boston Terrier colors.
We would be beholding to readers if they would share with us pictures of their “seal” dogs in the comments section below (not on Facebook where it’ll eventually get lost in time).
We end with useless trivia (our favorite kind): Seal brown is one of the official colors of Lehigh University, Brown University, the Cleveland Browns football team, and the engineering honor society, Tau Beta Pi.
Image: We found this fine illustration on a Russian website that even Google Translate didn’t translate. We’d very much like to give credit, or seek credit, to the artist. Anyone?