Has anyone seen this before?

[Blue feather]

I have a gray 13 yo gray mare with a malenoma the size of a large grapefruit on the left side of her neck, near her head. Vets have told me this is common in grays. Recently I've noticed her sweating on the left side of her neck near her malenoma down the top of her shoulder and no where else on her body. Does this mean anything? I have never seen anything like it. Has anyone ever experienced this before?

[Jenny]

Hi
I have not had this exact experience. But, I had a horse who I rescued who had sweeny. So he had nerve damage along his shoulder. he would have sweat patch on his neck when the rest of him was dry and a dry patch there when the rest of him was sweating. I had the vet who is is also a chiropractor and does some eastern medicine. she would put needles in this area along the nerve and attach it to some sort of electrodes and do shock therapy on him. We brought him back from sweeny which is very rare and he was almost normal. So the point of my long winded explanation is probably your mare has nerve damage there now, where the melanoma is. Along the same nerve branch as my gelding.

[Intrinsic Worth]

Strike a Balance, the dam of Peaks and Valleys, had melanomas all around her neck area that were quite large. The farm had her on 3 cimetidine once a day. That seem to slow down the growth and make her more comfortable.
As for the sweating, I've never seen that before.

[Mood Swings]

I think jenny's explanation makes perfect sense
I had a mare with nerve damage on the side of her neck and she would always sweat in that particular area.