Hives and edema in the legs..update: leukoclastic vasculitis

[meaty_ogre]

My horse presented with hives over a week ago. His turnout buddy also had them, so we are guessing something in his/their pasture. They are the only 2 on the farm who had hives. The other horse’s hives resolved with azium powder, but my horse’s hives have persisted and worsened despite two Dex injections, azium powder and 2 antihistamines (hydroxyzine and zyrtec). In addition to the hives, he developed edema in his legs above the knees and hocks. He has been very stiff and reluctant to move with the heat and swelling in the legs. He is at the vet hospital now.

My searches turned up similar symptoms after hoary alyssum ingestion, but we haven’t found any in the hay or pasture. We are in the Delmarva area. Has anyone else encountered similar symptoms? Any other ideas? There have been no dietary, bedding or other changes like shampoo, flysprays, etc. He was body clipped shortly before the onset of the hives.

Update: Skin biopsy came back - leukoclastic vasculitis.

[walkinthewalk]

Ant hills. Any chance they both got too close to a big fat ant hill?

Two years ago, I am pretty sure one of my horses rolled on one, over his neck area. That was one ugly, itchy, painful, skin peeling mess. I doctored him twice a day cleaning the area with Vetericyn, then putting Dermalog cream on the sores.

Keep a close eye on your horse that he doesn’t develop cellulitis, since he is having such a horrible reaction and not healing as fast as he should. Any open scratches or sores could make him a candidate:(

[meaty_ogre]

We didn’t find one in the pasture, but that was a thought. He’s at the vet hospital to try to get a handle on the hives and to monitor for founder, cellulitis, and any other possible complications.

[allisontatman]

Bumping this back up as this a dear friends horse and we are wracking our brains trying to figure this out. Maybe thinking hives and swelling legs might not be related? They presented over a week apart (hives first). Horse got hock injections 2 days before leg edema, but swelling is mostly in front legs and vet hospital does not think joint infection as hocks aren’t swollen. What else could cause a systemic reaction? Horse has no fever and vets are grasping at straws at our regions top vet hospital. Any ideas, no matter how off the wall, please share.

[JJARAB]

just a shot in the dark, but… photosensitivity, maybe? some of the symptoms sound similar to my gelding’s when he developed this last year, but it was in high summer when all the lovely toxic weeds were out. He had had his legs close clipped for show and has 4 whites. It presented in the front legs, scary edema with weeping/oozing and sloughing tissue. He got scrubbed, shaved and debrided, then washed every 48 with clorhexadine, also got two HEFTY doses of Excede and daily application of Panalog ointment. After that, he also wore fly boots daily until late fall when all the plants had died.

[flyracing]

His CBC/chem panel and PCV/TP is normal?

Is there petechiae on the gums?

Does the edema improve with walking? Is it pitting? Oozing?

[Ambitious_Kate]

And no spider bites, I don’t know where you live, but any other crawlies bits? NO midges?

[meaty_ogre]

Only blood work outside normal parameters was fibrinogen (700 I think) and SAA around 6000.

No fever, no apparent bite/sting mark, of course those aren’t always apparent. No fever. No respiratory symptoms. No diarrhea or other digestive upset.

Pasture management guy looked at pasture and didn’t find anything glaring. No change in hay, feed our bedding. Horse was dewormed with quest plus. I have owned this horse just under a year, and never used that on him before. No ulcers in mouth or anything like that. He also had hock injections (depo medrol only, no ha), a shot or two of acetyl d glucosamine, and was tranquilized for xrays for a farrier consult. Hives were present, but minimal at farrier visit. We were thinking mild allergic reaction at that point. I’m trying to list everything whether it seems significant or not.

In addition to the Dex shots and azium, he has been on prednisolone and minocycline. No change. Hives still present and edema in knees and forearms unchanged despite icing, hand walking and topical surpass. Has had 2 chlorhexadine baths.

[PushersBlue]

How long on the prednisolone?

I ask because my old gelding before he passed was on steroids to control airway bleeding/inflammation for an extended time. Eventually, he started to develop every skin issue under the sun including sudden cellulitis in all four, raging scratches, bleeding swollen coronet bands, and whole body hives that all shed off thankfully not taking his skin while his pasture mates were all just fine.

I’d wonder if the horse has an immune issue going on. Steroids affect that. Just a thought.

[meaty_ogre]

Just an update…
Skin biopsy came back. It was definitely not an allergic reaction. It turned out to be something called leukoclastic vasculitis. I had to google it after talking to the vet, and what I found mostly referred to the pastern version. We still don’t know what triggered it, but he is thankfully responding to treatment and looking more back to normal. Unfortunately it can recur.

[Zu_Zu]

Sending Jingles & AO for your gelding ~

Sending Jingles & AO for your gelding ~

((hugs)) laced with extra strength and patience for you ~