Sorry to hear about your friend's horse. No, my mare was a liver chestnut, but in her old age she sort of grayed out into a fleabitten gray. Genetically she was chestnut with red parents. She got tumors all over her neck and withers as well as up the backs of her legs. I do not remember what specific diagnosis that it was, I always get the terminology mixed up. However she had had several tumors removed over the years until they spread too far and covered areas too large to operate on. She deteriorated so quickly that I felt it was cruel to keep her alive. I donated her remains to a university for the animal science students, as the vet that worked closely with us taught at a university. They said upon examination she was full of tumors internally that had metastasized all over and spread to several vital organs. They were not raised or callus tumors like sarcoids, they kept appearing like ringworm, flat raw flaky patches. Several specialists examined skin scrapings and blood tests and found several mutations on several different occasions concurrent with findings in skin cancer. She did have sensitive skin and was prone to sun burn, it seemed like her muzzle and ears were always burned. I kept her inside most of time after the lesions started appearing. I know that lots of professionals say that the sun has nothing to do with cancer in horses. I can't help but think that it may play a role in some animals. If the Sun's rays radiate and do damage to the DNA of the skin while it is trying to repair itself, and causes mutations over time, it makes sense to me that a creature that spends so much time in the Sun would have some effect. My vet has always told me to sunscreen my horses as a precaution, it may sound silly to people, but at the very least it is keeping their coats from sun burning. It gives me a little peace of mind anyway. Thanks for the info though.
