brookcove
Posted : 8/26/2008 3:39:54 PM
It's a mutation in the breeds where it's part of the standard. But in other breeds it's usually a birth defect that is caused by the fetus absorbing genetic material from an unviable "littermate." I've seen this before - a Kelpie with two noses - bizarre, and she had a couple other issues. She ended up in Utah at Best Friends because she was just so unadoptable (minor aggression, really bad SA) but it was an awful shame to put her down because she was actually overall a nice dog.
I've also seen a dog that was both liver colored and black colored at the same time. This is a genetic impossibility - but again it was because in those areas the fetus had absorbed a littermate's genetic material.
I forget what this is called. There's a technical name.