I'm asking on behalf of a friend and dont have more details than this-- her gelding has been irritable recently. She's had two incidents of finding invertebrates up in there--a month or so ago a big tick bit him and a couple days ago she dug a dead horsefly out of his sheath. He is a gray and has had melanomas in/on or around his penis and sheath that her vet has been aware of, with advice to monitor for the time being.
After the horsefly incident he kept spotting blood. She took him to her vet and they found several large melanomas "in back of his penis, one with a necrotic center". She has indicated to me that this is "not good at all".
So, does anyone have experience dealing with this issue, know about treatments, prognosis and so on. She's vowing to both keep him comfortable and fight this. They are going to try cimetidine. I'm wondering if there are any palliative measures available, topical or otherwise. He's normally just the best mannered guy but she knew something was up when he started kicking under saddle at belly flies that werent there...
She has had to put down two beloved horses in the five years that I have known her. She will bankrupt herself to give her animals good care. This gelding is a real sweetie and her best friend in the world.