Oncept Melanoma Vaccine - for grey horses with melanoma

My grey mare, 12 yrs old, has recently developed a tumour in her parotid gland (situated just below her ear). It is aggressive. In order to halt this or hopefully regress this I have decided to proceed with the Oncept vaccine on vets advice. I was wondering what is the experience from those that have used ? as I understand it has been on the market for a few years now. Does anyone have feedback who has used and what are the long term effects ?

Also interested to hear from anyone that has had a horse with this type of tumour.

Check out the related posts on this thread https://www.chronofhorse.com/forum/forum/discussion-forums/horse-care/261149-melanoma-oncept-october-2017-post-137

The discussion above is me writing about my horse. To answer your question, he has been on Oncept for 4+ years now with no ill effects at all. The link above covers just about everything. Miracle drug, at least for my horse.


Thanks Madison and Oldernewbie for the link. Oldernewbie have you found during the 4 + years tumours have continued to shrink ? completely disappear ? have any new ones appeared ? just trying to work out the prognosis of my much loved horse.

Every horse reacts differently. For my horse, some of the melanomas completely disappeared and some shrank significantly. As far as I can tell, he has nothing new. Other people have not reported much reduction in size but the melanomas have quit growing. In some cases the injections have had no effect. Unfortunately there’s no way to predict what will happen until you go through the injection series.

If your vet wants to talk to my vet at Ohio State University, she is Dr. Teresa Burns. Great vet and person and has administered Oncept now to a number of horses. Not as many as Dr Philips, but still quite a few.

Good luck and keep us posted!


Is the cost coming down at all yet?

Came here to ask the same question! :yes:

I have no idea about the cost. I get the impression that vet schools charge less but that is based on gut feel not data. Call around, that’s my advice!

Yes it is fairly costly and also ongoing. I am in New Zealand so my vet has to import the vaccine. 4 injection comes to $3000. My mare has her 1st injection next week as soon as this vaccine arrives here :slight_smile: I am going to measure the tumour with calipers a few days prior so hopefully keep a good track of its size. I will keep updating here.


I’ve read a number of research papers, unfortunately the information is not free either :frowning: there has been some really good success with Oncept in the studies. The percentage was 75% of horses showing halting of tumour growth or regression. 75% is nearly 80% and that is nearly 8 in 10 horses! so it sounds promising.


Please keep us posted on your progress. I hope the Oncept works for your beloved horse!

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Very interested to hear how your mare responds, keeps up updated! Good luck to her, I hope this is successful!

Waiting for the vaccine to arrive this week ! for those interested in a case study: Holly is a purebred connemara mare, 12 years. She is young and super healthy and we have got the parotid tumor relatively early. So will be interested to see how Oncept works for her. Will keep you posted !


Vet booked with first vaccine today.

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I am sure your vet has read about the proper way to administer Oncept but just in case…

  1. Make sure they shave to the skin at the administration site. My boy gets his on the neck, Phillips found that the pectorals worked best - either way - no hair!
  2. This medication is administered with an intradermal injector. No needles - it’s like a nail gun that blows the medication through the skin. The injector must be held in place for 10 seconds after they set off the injector.
  3. The injector makes a loud noise when it goes off. My horse is an old pro at it now, but be prepared the first time for a big startle. We positioned him parallel to the stall wall with his head in the corner so he couldn’t jump forward, especially important since they have to hold the injector in place after it goes off.
  4. Since my boy is a shameless food-a-holic, a big serving of sweet feed or treats after the first injection was all the bribing he needed to stand like a statue from then on. Have treats in your pocket!

Since we usually draw a crowd at OSU for each injection, I make a point to talk to the students before the injection to make sure they are planning to do it correctly. I am not a fan of seeing my very costly vaccine go on the floor because someone thought they could make it up as they went along! So far, a good experience for all of us.

All the best and let us know how it goes. Fingers and hooves crossed!


Thanks for all the info! We sedated Holly just in case and it was injected into her pec muscle. The vet said it needs to be firmly up against the skin so makes sense with the shaving. Oh eek will mention for next one to hold in place for 10 seconds and i’ll shave the hair! Just read your message! so hoping is will work for us! It’s so expensive so want to do everything possible to ensure the best outcome.


Wow, how interesting!!

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Sounds more like Star Trek then a nail gun.


Yes it’s an intratransdermal injector that propels active through skin with air force. No needle. I’ve never seen this type of technology before! That’s technology for you :slight_smile: