Cancer and Grays

[guest@endurance.net]

K S SWIGART   katswig@earthlink.net

I vaguely recall having read in Horse Care magazine (so, yes, it was a
long time ago, since the magazine has been out of print for almost a
decade) that the same thing that causes a horse to turn gray (i.e. have no
melanin in the hair shaft, which is why the hair is white) is what causes
the melanomas.

That there is some alteration in the skin that changes the shape of the
hair follicle (or something like that) that makes it so that the melanin
gets trapped in the black skin rather than moving down the hair shaft and
giving the hair itself color.

It is not a matter of: "most gray horses inherited their gray gene from
the same source (although they probably did) and they inherited the
melanoma gene as well from the same source;" but rather, "the condition
that causes them to get melanomas is the same as the condition that causes
them to turn gray."

It has to do with how melanin is distributed in the skin (and coat)
causing both conditions.

However, just like in humans, not all melanomas are malignant (cancerous)
melanomas.  But it is my understanding that if the melanomas grow
internally, they can cause problems even if they are not malignant.

kat
Orange County, Calif.

p.s. I do not know if this is true, but it made some sense to me when I
read the article. And I do not remember how it is that these conclusions
were discovered.