catahoulas with a lot of white

Merle is a dominant gene. It does not exist where it isn't present. Having said that, there is a color factor known as "clear red" where the merle is masked but not visible. Those dogs will also have red noses . . I think they lack the ability to produce black . . sort of one step back from an albino wherein they produce pigment, just not black (maybe where the Foundation BMC guys got the idea for their so-called red albinos?). I acquired a leopard cow dog a year or so back and got mildly curious about this stuff. If you have any questions or can't find the answer on anything to do with merle, brindle, albinism or other color and inheritance factors in dogs . . . I suggest you google or contact Dr Sheila Schmutz. She is a PhD at the University of Saskatchewan in Canada and considered among the world's foremost experts on canine coat color genetics. Nice lady and you can find her contact info on her website.

Some of the yellow dogs of Bob Owens and Skoalbandett will occasionally throw red nosed pups. I've never been interested enough to try and prove it out . . but I believe those to be carriers of a recessive "clear red" factor tracing back to the Lewis Woodruff/Coffield Ranch leopard dogs in their ancestry.