Well in biology we learned that cancer can be genetic, and my friend has skin cancer as well as most of her family, so I don't know..

I never said that. Are you referring to my posts?
Sorry, but I was...You said that a responsible breed will kill a pup that doesn't match up to the standard...

Sorry about the homozygous merle confusion, it seems I'm not sure now if my breeder breeds merleXmerle as I read her article wrong.
Here is her article if you'd like a good read http://www.bconnex.net/~langevin/Color/color.html
By the way, I was talking about catahoula leopard dogs. Here is her article about deafness: http://www.bconnex.net/~langevin/Deafness/deafness.html
I see that for her upcoming litters she is only breeding one merle each time, so I'm not sure. I'll ask her.

It's interesting stuff.