Bizarre Hives and Antihistamines for the Horse who Presents w/ Occasional Hives?
My horse will every so often present with these bizarre hives. Sometimes they're the size of a softball and raised half an inch or so (in which case I usually only find 3-6 of these at a time) while other times he'll present with more typical hives. These reactions seem to happen at random--he's gotten them in the summer, fall, and even in the dead of winter. It seems to happen no more than a few times a year.
Today, my horse presented with two large "lumps" right where the girth would lie along his sternum. They were each about half the size of my fist and were quite hard. Then, I noticed that some of his other lymph nodes were swollen.?
One of his vets had given me some Dexamethasone to have on hand but the vet who was in today urged not to administer it without him being looked at since the swellings were so strange...Several new horses have come into the barn in the past week or so and I wanted to be sure it was nothing else...
Horse had no temp., no respiratory disturbances, etc. The vet gave him 10cc of Dexamethasone (which I already had) along with another injectable medication (that I can't remember, of course).
Vet recommended TriHist although luckily, he was out of it on the truck (and I checked CoTH and read of the side-effects before going ahead with it).
Does it seem like it'd be worthwhile to put a horse like this on an antihistamine (AniHist, HistAll)? The vet said it takes a few weeks for it to build up in their systems and that he typically doesn't keep a horse on it all the time. If I kept my horse on it, would it maybe help in preventing these skin reactions (hives)?
And, have you ever had a horse present with such bizarre hives like these before? TIA!