If you've followed for a little while, you know that Tristan has struggled on and off with hives over the last few years. I'm pretty convinced that it has to do with his Cushings diagnosis - his immune system just can't cope as well as it used to.
This year's bout held off for a long time, since we were proactive - he's been wearing fly gear and getting a low dose of OTC cetirizine all summer - but when they hit, they came with a vengeance.
First appearance was, of course, about a week before I left for the honeymoon.
These blew up in less than two hours: he was totally fine when the barn manager left after grain, and covered all over when I got there to ride at 7pm.
We started with IM benedryl, a dose that the vet had left with us after last fall's shenanigans with his tail tumor (because one of the possible side effects of the chemo beads was anaphylactic shock or a lesser but still serious sudden allergic reaction, isn't Tristan FUN?). (For those playing along at home, this was per the vet's instructions while on the phone with her and after having sent her the above pictures.)
That helped, but they were back the next day. So I spent a few days giving him a bath every night with long rinses of cold water and a sensitive skin shampoo. In the meantime, no more grass for him; he was sent to a dry lot with tossed hay.
(We also did some work trying to isolate other factors, but nothing had changed for him, and he wasn't getting anything that was not shared with other horses, from hay to grain to water to shavings and so on and so forth. Our best guess was that something was blooming or going to seed in the pasture - which even then are of course mowed down regularly - and that was setting him off.)
Yeah, he LOVED that.
That helped but it did not actually solve anything. Next up: the vet. I couldn't be there when she was, so after some phone calls and emails back and forth, during which I was able to dig back into my obsessive notes and document for her the dates and duration of Tristan's bouts of hives for the past three years, we went forward with a course of treatment.
First: since he is Cushings but not insulin-resistant, and because his Cushings is under control and responsive to pergolide, he was a candidate for dex. So he got a shot of dex at the vet visit and then 5 more days of decreasing dosage, which made a big difference.
Second: he had been getting 20mg cetirizine 1xdaily as a preventative. He was now to go up to 200mg 2xdaily as a treatment.
Except by the time the cetirizine order was called in to Wedgewood I was in Europe so the vet dropped off a supply from her own stores and that took a little longer, so in the meantime the hives came back. Which meant that he didn't get ridden at all while I was away - so basically he did not get ridden through all of August. I didn't want to irritate the hives, or rev up his metabolism in a way that would make them worse in case this was an allergic reaction that went deeper.
Once he got the higher dose of cetirizine on board, the hives receded and - knock wood - it's been almost 4 weeks and they have not returned.
In the meantime, the Wedgewood order came in and we are leaving the danger season, so I have a fresh bucket of cetirizine ($$$, sigh) in the fridge to keep good until next June, when he will start on it and stay on it through the summer and we will hopefully not monkey around with this bullshit again.
I swear, I keep telling people that he used to be an easy keeper and they don't believe me.