Horse covered in hard bumps - eosinophilic granuloma? Warbles?

[Chimera09]

I’m new here - I read the forums frequently and have found a wealth of information here that has helped me with my riding and horse care in general. But this is my first time posting, because I haven’t been able to find an answer to my question and I’m hoping you guys will be able to shed some light on the subject.

Backstory - I’m riding a AQHA gelding about 8 years old. This horse came to our barn this summer - he had many hard bumps all over his body (in clusters on his legs, on his back, belly, chest - pretty much everywhere), and we were told by previous owners that he was allergic to bug bites and that’s why he had the bumps. We gave him a fly sheet, but we didn’t see any change in the bumps during the summer - some may have gotten harder or a bit larger, but I can’t be certain he didn’t get new bumps. They didn’t seem to bother him, and the hair grew normally over the bumps, so we left them alone for the time being, waiting to see if the bumps resolved on their own once the bugs were gone for the year. Fast forward to now - bumps are still there. A visit with the vet didn’t give us much info - suggestions included rubbing icthamol (sp) over the bumps, injecting them with depo, or doing a biopsy. We decided to try the least invasive option first, but I don’t see any change in the bumps after a week of using the icthamol. Also, the bumps are so widespread across his body that it’s difficult to keep track, so I’ve been focusing my efforts on a few prominent bumps.

Today after my ride when I was grooming him I noticed one of the bumps had opened. A few people at the barn looked with me and one suggested they may be warbles. But would warbles still be in his skin if the bumps have been there since at least august? And I don’t know how long he had the bumps before he arrived. Eosinophilic granuloma was also another guess. But I’m hoping someone here may have some insight in case they’ve seen anything like this before. When the vet comes I want to make sure I ask the right questions, so the more information I have the better. Thank you in advance for any advice you can offer.

This is when I first saw the opened bump. A friend said it looked like it could be warbles - but wouldn’t it have emerged after being there since at least August?

This isn’t after someone poked at it a few minutes (he didn’t seem to mind) and I’d put a bit of icthamol on the opening.

Please let me know if the images aren’t working. Thanks!

[Simkie]

Yick.

A needle biopsy is so minority invasive, I would definitely start there.

When you do find out the cause, come back and tell us! Looks interesting

[Chimera09]

Do you mean they would just use a needle to take a small sample of the bump? The vet insinuated that the biopsy was invasive, and that he’d need to be sedated - I think she wanted to cut out a whole bump. I’ll clarify and ask about needle biopsy at her next visit. Also someone mentioned that if it is sarcoids, doing a biopsy could “anger” the area and cause the cancer to spread. Also, I should mention - they appear to be subcutaneous. If you grab at one of the bumps you can feel the whole thing in his skin. Not sure if this is good or bad, though!

[Wayside]

If they’re warbles, the larvae should grow for two months or so after nearing the skin, then open a breating hole and emerge in ~30 days after the breathing hole opens, if I recall correctly.

And there’s a small chance of anaphylactic shock if a grub is crushed to death or otherwise killed while it’s still in place, so I wouldn’t be squishing it too vigorously or poking it with a needle myself if it was me.

The vet should be able to extract them carefully if you’re unwilling to wait.

[yourcolorfuladdictio]

I’d definitely biopsy, you can’t treat something if you don’t know what it is. It’s just like someone having a mole removed, a little punch/cut and then less than 10 stitches.

[Simkie]

[QUOTE=Chimera09;8942762]
Do you mean they would just use a needle to take a small sample of the bump? [/QUOTE]

Yup. Fine needle aspirate

[merrygoround]

IME warbles if left alone vanish on their own, sometimes after months. Those under a saddle area can be problematic necessitating a thick felted saddle pad with hole cut at the appropriate spots. Crushed, they can take a long time to heal.

[Chimera09]

[QUOTE=merrygoround;8943661]
IME warbles if left alone vanish on their own, sometimes after months. Those under a saddle area can be problematic necessitating a thick felted saddle pad with hole cut at the appropriate spots. Crushed, they can take a long time to heal.[/QUOTE]

Two of the largest bumps are definitely in a saddle pad area - I’m pretty sure that’s why this big one opened up. He isn’t clipped yet, and he was hot and sweaty and I was cleaning him up when the top of the bump rubbed off. So I’m pretty sure it was heat/moisture/pressure/friction that caused it to open (I use a thick sheepskin half pad with rolled edges on top of a clean saddle pad, but apparently it’s still irritating him). I’m hesitant to clip him before I know what’s wrong because I don’t want to irritate the bumps or cause infection. I’ll ask my trainer tomorrow if he should be ridden until we figure this out - I don’t want to hurt him or exacerbate the situation. He’s one of those special snowflakes, there’s always SOMETHING not quite right. He’s already had too much time off due to an illness in late summer/early fall - he’s just getting back into regular work. And he’s green. Oh boy. :no:

[Chimera09]

So quick update - he was a rockstar during our hack today, and part of me wonders if it’s because I used an extra gel pad on top of his usual saddle pad and half pad. Maybe the bumps under the saddle have been more sensitive than we thought. But he was feeling great today and we took some more time to examine the bumps all over his body just to see if the icthamol was drawing anything out or if anything had changed. Nothing. I’m beginning to highly doubt its warbles. I’m betting on eosinophilic granulomas from bug bites. Vet comes tomorrow and I’m going to ask about fine needle aspirate and see what she thinks. I’ll let you guys know how it goes. Thanks for the suggestions and help.

[MissAriel]

Thanks for the update. I’m curious to hear the vet’s update.

[Manahmanah]

Mine got the same thing you describe one summer when the horse flies were extremely horrid. Large, hard bumps. Sometimes one would erupt and spit out some goo. They didn’t seem to bother him at all but the ones under the saddle pad would bleed

Waited over the winter for them to clear up, vet prescribed some steroid sprays and other stuff that didn’t work. Got them biopsied in the spring, turned out to be collagen granulomas. They did have to sedate and also blocked with a local on the ones they harvested from.

Strangest thing is… about 2 months after they did the biopsies, they all started slowly erupting and all cleared up shortly after. For a timeframe… I remember it was at least 8 months fromy onset to resolution… only because I had them looked at the first time during fall shots, twice more during the winter and did the biopsy shortly after spring shots.