Since moving to our new location, my horse has developed intermittent runny poop. I have tried everything and have had the vet out numerous times with not much help on that end of things. I am pretty sure it's environmental in that he did not have these problems where we lived prior to moving to this location. We have switched barns, paddocks in the various barns, tried to see if it's seasonal, put him on a regime for sand, etc.
Before taking him to state for goodness knows what tests, I would like to do a metronidazole trial. (My rationale for this is that my two dogs since moving here have periodically had to have a course of metronidazole fall and spring for the same problem) Having done some research in the area of diarrhea in horses, I found some information on dosing with metronidazole for this problem.
I am wondering a. if anyone out there has found this effective and b. what is the dosage and what is the time period for the dosage..
My horse developed intermittent diarrhea shortly after I got him. We tried all sorts of things -- cutting out all supplements, trying psyllium, probiotics, yoghurt, Restore (a prescription probiotic-type supplement), Panacur Powerpak, Succeed. Apart from the mild runs, he was absolutely fine.
I finally took him to the vet clinic and they ran a fecal which came back normal. His overall appearance was just too positive to suggest ulcers so we didn't scope him.
The vet then put him on a course of Metronidazole and that completely took care of the problem.
A short time later we had a flare-up at a show where the bedding was straw and he was eating some of it. I gave I think two doses of it (with vet approval) and it cleared up immediately.
I've since concluded that my horse is especially sensitive to feed changes -- not in terms of introducing new feed, which is always done gradually, but when we get a new batch of hay or have a different source of hay due to being at a show. I now give him Aloe Vera juice with his morning grain and this seems to keep it pretty much in check. I haven't had the need to use Metronidazole in years.
But!! Big Caveat: I am not a vet and I am not diagnosing your horse. I'm just sharing my experience.
Metronidazole is an antibiotic, but it also has some inflammatory properties on the gut - which is why it works sometimes when there is no bacterial infection. A fecal culture would be ideal first, because there may be something cooking in there that is not sensitive to metronidazole - and the culture should include a "sensitivity" which tells you exactly which antibiotic will work for the nasty organism you are trying to fight.
Your situation sounds like there may be a hypersensitivity to something in the new environment - a new hay supplier? New pasture? New feed? New supplement? If you've added anything new or different you may want to remove it and see if that helps.