I hope I can explain this and others may have different opinions.
That looks to me like seborrheal type dander than can often show up after an event like Scratches — even long after.
It’s possible the current antibiotics are affecting something that has never 100% gone away or, even if it has, that area is still sensitive enough to be affected by a drug strong enough to make Harley lose his appetite.
Joker has always had extremely thick hair running down the “seam” of his hind legs. I keep it shaved during the warm months and cut back during the cold months because he will get that funny looking dander either from sweat and dirt build up or just plain sweat in the summer.
As far as the difference in the feel of the hair, I would be willing to blame that on a long-term residual effect of Scratches. Most horses probably don’t get that but Harley is his own person, so after-effects may present differently on him:)
The hair looks healthy, so doing what you’re doing should be enough, unless you see his skin start to turn raw.
Also watch him for butt, chest, or head rubbing, or depression. If depression enters, along with loss of appetite I would call the vet as that may mean Harley needs the amount of antibiotics cut back.
FWIW, depression and loss of appetite can happen with Cushings horses, when first starting them out in Prascend. You mention loss of appetite so I bring up the fact the Harley’s antibiotic is some potent stuff and may need cut back before he finishes the prescription.
When I had Joker on Methocarbomol,when he re-fractured his back last year, I had to take him off of it three days ahead of schedule. It is a powerful muscle relaxer that I had never heard of before.
Joker didn’t break out in hives but his whole body started to itch. Soon as I stopped the Methocarbomol his itching started to subside.
I am really happy to hear the metronidazole seems to be working for Harley. He will likely need a high caliber pre-probiotic after he’s done flushing his system of parasites with this drug:)
Yes, I think this is the most likely explanation. I think it was probably there before and we just didn't notice it because he gets very fuzzing legs in winter so it was mostly covered up, and since his hair is light, it blended in. It does look like some sort of dander, I've just never seen it this thick, but then again, this was the worse patch of scratches he had and we battled it for months (vet was involved, don't worry).
He's otherwise behaving normally, but Harley was always cranky in the winter. We assumed the loose stool was causing this, along with his arthritis. I wouldn't say he's depressed, but in previous winters, he has been. It's worse when the cold is bad - he'll just stand in the stall with his head down. This year, he's better, probably because our winter has been very mild so far. He plays with Rusty, chases the two other horses off the hay (even when he's not that hungry - he just wants to prove a point). DD has been riding him this week, and he's very energetic.
It is a very potent drug though, and he's already on a probiotic, but I may well add to it when we're done. Will keep an eye on things and talk to the vet if I feel like it's too much for him. But he's suffered from chronic diarrhea for the last three winters, so that could not have been good for his body either. It makes sense that we need to bring out the big guns to get rid of that mess. If we succeed, then we'll move onto bringing back his gut flora.
Thanks for all the ideas everyone!