My 10 year old grey mare has a few melanomas under her tail. She had one tiny one for the longest time but now has several. They’re all small (largest is smaller than a dime). I’ve been looking into the vaccine, Oncept. It seems to be quite effective in horses but using it in horses is considered “extra-label use”. It’s quite pricy too ($3000 for initial treatment and then another $500-1000 every year). Does anyone have any experience with it or have other suggestions? Also, any experience with insurance covering the cost? Thanks so much!
That vaccine is most effective in horses like your mare.
The sooner is started, the better it works.
It should stop it from growing and maybe even reduce them in size.
No side effects up to now.
That is according to our vets.
OP - There was a long thread where someone reported their experience with Oncept. Initially started in 2014 but with some more recent follow up.
https://www.chronofhorse.com/forum/f…post-173/page7
I can almost guarantee that insurance will not cover given the off label use. And if you get any help on a first treatment, they will likely be excluded going forward -
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Oncept is not FDA approved for treating melanoma in horses, and for this reason you are unlikely to see this treatment covered by insurance. It’s probably best you call your insurance policy claim office to ask what their position is on covering Oncept as you consider your options. If your horse isn’t currently insured, any new insurance would carry a lifetime exclusion for melanomas. If you try to get insurance without disclosing the melanoma history, your vet is certain to clue in the insurance company if you file a claim, and it would be denied due to the pre-existing, nondisclosed condition.
Yeah, I’d not at all expect insurance to cover oncept. At the very least, being grey is a pre-existing condition and grey horses are more likely to get melanoma than not.
I treated my now ten year old mare with oncept last summer, and we’re now due for the first “every six months” injection (it’s been delayed due to covid.) Her melanomas got slightly smaller through the loading series, stayed that way for a few months, and are now growing again.
I’ll continue, because what else do you do? But I worry very much about whatever internal tumors we cannot see and the cost/effort/consequences of debulking the tumors we can see…because even with oncept, we’re probably to the point where debulking is the smart thing to do, and that’s pretty disheartening.
Here’s a better link to my now 6+ year old thread about my horse and Oncept.
https://www.chronofhorse.com/forum/f…pdate-post-173
After all this time and expense, I have to say that I am still glad I embarked on this journey. He is retired now and we’ve seen some changes for the worse in his eye and he had surgery last year for tumors on his penis. However, he is definitely pasture sound and rules the roost. No way of knowing, but I’m sure that without Oncept he would have been a goner long ago.
He had insurance once upon a time, but when his ocular melanoma first appeared, that was the end of that. They excluded it and since melanoma could be part of many other issues, I was sure that they would deny just about everything he might have.
Early is better, don’t expect miracles, but it does very much help in many of the horses OSU has treated with it.
Good luck!
ETA: If you look at the thread above, you will find a link to an article that describes all of the possible melanoma treatments. You have to pay for it, but it is well worth the cost. I will say that many of the other suggestions I have seen over the years (turmeric, various and sundry supplements) have no scientific proof of efficacy. Cimetidine, also frequently suggested, had one trial with 3 horses and very weak positive results. IMHO, don’t waste your money on the stuff with no evidence. At least Oncept has a documented track record and was doing well enough that it is currently in trials to make it onlabel for horses… If you can’t afford it now, save your money and start it when you can.
