Friday, July 24, 2015

What are these spots on my horse's neck?

A few weeks ago, I noticed these spots on Tristan's neck. I've thought about it on and off since, and I can't figure out what they are.

Two adjacent spots on the left side of his neck - can you see them, just below the bottom end of his freezebrand, and above the wet hair? 

This one's a little harder to see, but: look at the corner formed by his wet hair, just up from the bottom of his neck. Now track up. It looks almost like a coffee ring on his neck.

On the left side of his neck, it's almost like the hair is thinner and darker simultaneously. On the right side, it's just discolored.

One theory is that they're just weird bug bites. He has always reacted excessively to bug bites, from huge seeping welts to hives.

Another theory, and I am leaning toward this one, is that these are reactions to his IM Pentosan shots. But three separate spots would mean that the oldest of them is at least 3 months old. I don't remember seeing them even two months ago, much less three. It's possible I'm just wildly unobservant about things that are not his legs, but I don't think so.

Any guesses?


  1. I looked at your first picture and thought, that's a brand on his neck not strange spots, your horse is a mustang you dingdong. And then I remembered whose blog I was reading. Sorry not much actual help

  2. A ring? And you are having a wet summer? Ringworm, which isn't really a ring but a fungus?

    Try an anti-fungal on it and see if it goes away. Tea tree oil or No Thrush dry powder (I highly recommend the No Thrush - its good for rain rot as well) would be my recommendation.

  3. Weird!! I don't know what that could be- maybe ringworm, as Karen mentioned? Pictures of the stuff look kind of similar.

  4. huh, no idea really. i've never heard of pentosan doing that but i suppose it's possible?

  5. My horse gets a lot of pentosan injections. I do one per week. His neck is a mess. Large areas of discoloration. He is a chestnut and the discoloration turns like orange. Also, he loses hair on the spot. The hair grows back seasonally, but never returns to normal. He also gets lumps at the injection site. My vet told me this is a know fact of Pentosan and caused by the preservative they use. It used to be that Pentosan needed to be refrigerated and now it doesn't with the preservative. I'm not showing, so I can live with the discoloration. I guess it's worth it because Pentosan does work on helping the horse.


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