My boy came into the barn from an auction, and had obviously not been cared for properly for some time prior to his arrival at the auction. Feet hadn't been trimmed recently, needed dental work, etc. Not emaciated, but not at his proper weight either.
He also had chronically loose stools. Anywhere from grassy little soft plops to cow-pat consistency. I bought him about 8 months into this, and he'd been fed up to a more proper weight, had all his dental, farrier, etc. He was in pretty good shape except for this loose manure. Tail spent a lot of time being naaasty as a result, and all his farts were unappealingly wet. But he wasn't having trouble maintaining weight, skin and coat were fine, etc., he passed the vet check with a body condition score of 6, and neither I nor the seller remembered to mention the manure issue to the vet at the time. Horse is 17, previously a high-end competitor, so it could have been any number of things.
We didn't worry too much about it. Over the winter, I put him on a senior horse supplement, primarily for his joints, but it also had plenty of nutrients and probiotics, and it didn't affect his manure. I later added an omega-3 supplement because he doesn't get much pasture grass (he has 8 flakes plus a fairly small quantity of low-carb grain pellets to carry the supplements in per day). That also had a bunch of probiotics, and while his coat is nice and shiny, the manure didn't change.
At this point, it was Spring Shot Time, so I asked the vet about the manure, and he suggested a month of Probios. No apparent change, so when the vet was back out for Round Two of the Spring Shots, I got him to acupuncture the horse. He also suggested a five-day treatment of that antibiotic they give for giardia - in people, it's Flagyl. Metronizadole, or something like that.
Well, the loose manure cleared up RIGHT away, and he started making proper pellet-y horse apples, little dry ones, and - jeez - GAINING WEIGHT, and no more juicy farts. That is, until the five-day course of antibiotics was up, and the rest of of is kind of creeping back. His manure isn't so much dry horse apples, but wet, not cow-flops again, but not like it was. And even though his tail is still clean, he's got a wet mark like before on his bohunkus, and when he cut one in the crossties this morning, it wasn't squirty but had a juicy sound to it.
Vet was closed today, of course, so I couldn't ring them up (it's obviously not an *emergency*). I'll call tomorrow, but in the meantime, I'm wondering if anyone has treated for giardia before and had the symptoms creep back, I'm thinking maybe the course of antibiotics might not have been long enough. Either that, or we need another round of acupuncture, but I'm going to go with the antibiotics as the most likely cause of the problem clearing up (mostly).
Is there a test that can be done for this? I don't want to give him more antibiotics unless it's pretty sure that this is just a bacterial thing...but given how quickly he started to put on weight once the loose stools stopped, I don't want to leave him in that state if there's something I can do about it.