White colored chests on puppies- why ? - Page 3

The migration of melanocytes is also another factor. In fetal development melanocytes, pigmented cells, move from several sites on the top of the head and along the spine to the rest of the body. They migrate from the dorsal line down to the rest of the body. Most of this is complete in utero, but sometimes finalized post-whelp; part of the reason puppies can get their colors as they age, and lose the white tips. I believe the S allele can have some effect on where migration stops, and I have heard uterine temperature can as well, though I can't say for certain on that last one.

My girl definitely has it:

No Fero in my bloodlines, all my pups had white spot, they all were dark saddled back or bi-color have traced most of them and the spot disappeared with adult shedding . Cant help with why, but 33 pups later it has never failed , so dont judge a dog by a white spot but by its blood line, even a dark dog may bleed the white to nothing you would notice.

          Where is Mudwick....????

Behaviourist Eberhard Trumler explained white spots: His research on dogs and Dingo's showed that all domesticated dogs have an altruistic gene for white colour. This means, in pure breed dogs not normally exhibiting white, this gene always lies dormant but can become recessive (and visible) on occasion.
This is a little reminder that our dogs stem from wolves at the beginning of their ancestorial line. As you see in some puppies, the visible white marks from a resessive gene "disappear" in the adult dog, as the dominant genes for colour in these dogs grow more hair in the desired colour of the particular breed (e.g.tan). The few hairs of white are mixed into the other colour (like tan) and hardly or not visible anymore.