Yesterday I noticed my mare had broken out in these raw looking sores along one side of her mouth. It is not blistered, weeping or oozing, just very raw.
The shiny look in the picture is because I had just applied some neosporin antibiotic ointment to it. It doesn't seem to be particularly painful for her, but it looks
very uncomfortable. In real life, it looks a lot more red and raw than it does in the picture.
There are definitely a smattering of buttercups in our pasture, though the pasture itself is in decent shape after having ~6 months resting before the horses went back out on it 3 weeks ago. I looked closely today and there do seem to be some patches of buttercup where stems have been nibbled.
Neither of my other two mares have these sores, though one is all of a sudden having runny diarrhea, which I understand can also be associated with eating buttercups. I've read that horses won't usually eat them unless they are "close to starving," which these horses certainly aren't. In addition to the decent pasture, I keep hay they like out in nets all day, so they have other options if they're actually hungry.
We also have "poison parsnip" here. This is the first year I've ever seen it in our pastures, and we used a topical weed killer on it about two weeks before the horses had access to the pasture. It also grows along the roads, and I do sometimes let my mare grab a few mouthfuls of grass while we're out riding-however, the poison parsnip is very noticeable, and I'm really paranoid about it, so I think it would be unlikely for her to accidentally eat it along the road. Also, getting into that weed tends to cause weeping, oozing sores and that's not what's happening here.
Anyone ever dealt with buttercup poisoning? Does this look similar? If so, how did you treat it? Will weedwhacking the plants down take care of the problem?