Melanoma - Oncept - January 2022 - Update post 185

So I got the pathology report today for the extra tests on the lump from his gaskin. The lump was a mast cell tumor, which the lit says is rare in horses. So of course we have it! My horse, the walking dermatology textbook! Excision is the cure, which is done now of course, and the margins were clear. So, only task now it to just keep an eye on his body for new growths.

He returned to his job of ruling the yearlings on Monday and seems to be just fine.

It certainly has been an experience with him! :eek::eek::yes:


Wow! It must at least feel good to know what the lump is and know that it is taken care of.

Thank you for sharing your journey’s ups, downs and insights. :yes:

Oh my gosh what a rollercoaster ride. Interesting how the Mast cell tumour is not targeted by the Oncept, only very specific to melanoma. It is like a science experiment alright !

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It was off to OSU this morning for Mr Ay-rab’s semi-annual Oncept injection. I was very happy with the results - no new mast cell tumors, old melanomas stable to pretty stable, no re-growth of melanomas on his penis. Perhaps the only area of concern is his eye as it seems to look different both to me and to Dr Burns, but not radically so. I think another trip to his ophthalmologist is in his future, but probably not until early spring unless something really goes haywire. I am not a fan of driving in the snow with a horse trailer.

He got his exam, injection, treats, hopped back on the trailer, and ruined a perfectly good grooming job when he got home by rolling on both sides in the muddiest part of the field. Life is good!


Hello. I have a 16 yr old grey Arab with a few melanomas in his sheath. I am serious about the oncept vaccine but have had trouble locating a vet that can do it. I have been quoted several thousand dollars for the injections, plus a office visit. Of course I am willing to do this but also would like to save some money if I can. does anyone have any suggestions? I am in Norco and my main vet cannot get the vaccine as he is not a oncologist nor a internist. Please help. Thanks, Robin


You know, around here (Ohio), Merial is letting regular horse vets without any special credentials buy and administer Oncept. All they have to do is buy the intradermal injector. This is a change from their earlier policies which did require a diplomate in oncology or internal medicine. It is nutty to me that they have apparently different policies in different parts of the country? I think I would have your vet run this up the chain of command (so to speak) at Merial and see if he/she can get a read that is more consistent with other parts of the country. Second choice is to try a vet school and see if they can help.

Good luck and let us know how it goes.

Hi. thank you! I did try Western University out here and left them a message. I hope they get back to me soon. If I was NOT in California things would be so much easier for sure.Or, the UK where they do it all the time.

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Be persistent. Not everyone knows about Oncept, and even if they do know about it, aren’t too motivated to start using it unless a client insists. Good luck!

It was time for Mr. Ay-rab’s 6 month Oncept injection - quite a different trip in the COVID-19 era! You pull in, call a phone number, the tech and intern come out and get the horse. Wait a few minutes, and the tech and intern bring back a horse with a new injection. No gaggle of vet students to take a look at Mr. A’s eye, no gossip with vet. I really miss that!

The good news is - he’s doing fine. No big changes. No adverse reaction to the injection. Took him home and we’re both happy!

Stay safe everyone!

Back to OSU today for Mr Ay-rab’s 6 month Oncept injection and mini Christmas party in the parking lot, since we can’t go in the building. Happy to report that he is doing fine. His fans at OSU miss him. Everything stable and small!

Hard to believe that in January it will be 7 years since his first injection!

Hope everyone has a happy holiday season and a safe and covid-free new year!!!

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Mr Ay-rab returned to OSU for his 6 month Oncept injection, first of the post-COVID (we hope) era. Everything went well as usual - we were in and out quickly. At least I got to go in the building with him and visit with his fans.

I would say overall that he is doing well. I do think the growth in his eye has gotten a bit bigger and he has one melanoma under his tail that is now a tiny bit bigger. However, the lumps on his jugular groove have been gone for some time. For a 15 year old, he is sound and in good condition. My trainer brought him out of retirement to pony a young 'un earlier this year - she (the young horse) tried to lay down the first time they ponied her and he just looked at her like she was crazy.

Have a great summer and stay safe and healthy!


OMG!!! Thank you so much for this thread!! It is so long, comprehensive and as such, so insightful! What a go you two have had! CONGRATULATIONS!
We have an 11 yo Mustang pony, who is obviously grey, or why would I have found this thread, she has no obvious melanomas. Has there been any evidence that this “vaccine” can be used as a “vaccine” to front-load the immune system to prevent melanoma rather than a targeted treatment?
This pony is my daughter’s life, heart and soul, so if there is ANY evidence that this would be something to pursue, I would be on board for trying it!
Thank you for being such an invaluable resource to others looking for information! :heart:
I can’t wait to follow the rest of your journey! :pray:t3::heart::horse:

We are on board with Oncept and are extrememly lucky to have both New Bolton and Veterinary Oncology right in our backyard. DD’s welsh/TB was diagnosed with a small melanoma under his tail during routine exam. By the time we discussed the options and made the appt to have it removed, two more appeared in the same area. NB was afraid there was not enough to make the vaccine, but it turns out we were able to get 16 injections from the three sites. Surgery was uneventful, quick and the cost was less than I expected ($450). Brought him home with no down time and the sites healed clean and very easy. The vaccines cost $600, which again I didn’t think was that bad. He had his first dose yesterday with the immune booster as well. He’ll get the next one in two weeks so I’ll keep you updated!

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Well, thank you! I am so glad it has been helpful to you!

I know a couple of people have talked about using Oncept preventively, but there haven’t been any studies to test whether it works that way or not. Oncept use in horses is technically an off label use of the drug. I know Oncept is currently in trials to be approved for horses; that has been underway for at least 2 years. So maybe… after all that is finished, someone will take a stab at studying whether it is useful if used before melanomas are seen.

I realize you can’t know the breeding of your Mustang, but I will tell you that for some reason gray QHs do not get melanomas as frequently as Arabs, Lippazaners, TBs, and other commonly gray horses. So maybe maybe your risk of seeing them is not so great since I imagine she got the gray from a QH along the way??? Also, since she is already 11 and has nothing visible, she may be the horse (fairly common) who, if they do get melanomas, get the slow growing and not life threatening kind, and live a long life and die of something other than melanoma, even if they have a few visible eventually.

So, no definite answers here, but hope these random comments are helpful!

Back to OSU Friday for Mr Ay-rab’s regularly scheduled Oncept injection. This trip was our 8th anniversary and the old man (16 now) is still hanging in there in good shape. His only issue is two small growths on his anus which they can remove standing. Otherwise, everything else is stable.

His attending vet commented that they have 40-50 horses on Oncept now, which is great. Mr Ay-rab is legendary in his role of Patient Number One!

Stay safe everyone!


That is fabulous news!!!

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I still think about you and your mare. Hope your heart is healing well hugs!

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Thank you. I certainly miss that mare a lot, but it is gratifying to see continued good news from you and your boy. The Oncept-dubious vets here ought to read your thread. :wink:


This is great news! My horse had his first 6 month injection yesterday. He had the one remaining melanoma, left after the loading doses,and one small additional one on his sheath. There was a tiny bump under his tail, but not even clear if that was a melanoma. It isn’t visible to the eye, but can be felt.
This is far better result than having surgery to remove a bunch and 4 months later having 6 or so.
My vet couldn’t be there, so another vet from the practice did the procedure. She is not sold on the vaccine.
Do y’all have all melanomas removed, or just let them be?

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Great news for you too!

If they see it work, I don’t understand why some vets aren’t sold on the vaccine. ??? Yes, it may only work in 50% of the cases, but that’s a huge improvement over anything else available.

My horse has not had a lot of external melanomas. Unfortunately, the external ones he did have interfered with urination, so they had to come off. The new ones on his anus are not bothering anything yet, but both vet and I feel like it’s much better to take them off before they cause any trouble. He has one under his tail that is small and probably won’t ever bother anything, but if we are going to numb him up to take the others off, might as well get rid of that one too.

Good luck and hoping for continued good news!

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