In this conversational video, Dr. Conor Brady and two other speakers explore why dogs are attracted to horse feces. They discuss the hypothesis that dogs seek post‑biotics and other metabolites produced by the horse’s hindgut microbiome, which may be altered by the horse’s diet and deworming status. The participants compare different anthelmintics—ivermectin, Panacur, Strongid—and how these drugs, many of which have antibiotic properties, could change the fecal biome and make the poo more or less appealing to dogs. They note the difficulty of determining whether a dog’s interest is due to recent worming or other factors without long‑term observation. Finally, they give practical advice: herbivore feces (horse, rabbit, sheep) are generally safe and even beneficial for dogs, whereas coprophagy of other dogs’ or cats’ feces should be discouraged due to parasite risk and hygiene concerns.
Chapters
Horse poo. Why do dogs love it so much? How damaging can it be to a dog if a horse has just been wormed?
Have a bit in that. I had a horsey person who told me her dogs only eat the poo of the horses she doesn't worm. So she said that they could smell it. And because it alters the biome of the poo, I'd imagine it's probably— we're not quite sure why they're eating that poo. So hindgut fermenters will have a different poo profile than your other regular kind of 4 good dudes. And so is it that they're after the byproducts of the gut flora in that enormous colon and stuff? Is it higher in vitamin D?
Hold on.
Yeah, no.
So yeah, I think like maybe somebody else said that the postbiotics, postbiotics, I think are a valid thing that dogs will seek out.
Yeah.
So not eating all the vitamins, vitamin Bs, etc. that are part of those postbiotics. I can totally understand why dogs would be attracted to some of that in various forms. It's interesting, isn't it? There's some wormers that definitively we know is antibiotics and will change the biome as well. And I'm guessing to some degree all wormers will do that, but I think some will be detected more than others. And it'll be interesting in some of the avermectins, so ivermectin and things like that. Would they be detected in the same way as some of the Panacur and Strongid Ps and those sort of things?
So that's interesting.
I think it's just on a practical note though, if unless you own the horse or you know the person who is and you know when they are worming, it would be very difficult to tell whether your dog is going off the poo because of whatever the horse had eaten that the day before or whatever. Or whether it is because of the worming, I think you'd have to do, you know, do observe the horses and the dogs and what have you over an extended period. Generally speaking though, I think horse poo, rabbit poo, sheep poo, and all of those kind of things are absolutely great, and I do encourage them. But eating dog poo, cat poo, that's to be avoided if at all possible. It probably won't kill them. It might set them up for getting parasites and what have you. But yeah, it's just not very pleasant if they come and lick your face.
