Just recently I noticed that we've had a flourishing of horsetail behind our house.
A couple weeks before I thought we had hardly any, and now we seem to have a crop! We let our goats out of their pen daily to browse, and I have been pretty successful in keeping them away from the back, but they do sometimes get back there, and I've seen them munch on the horsetail. Also, we keep our little Nigerian doeling in our fenced area of the backyard, and I've noticed a few sprouts of horsetail weaseling it's way into there. 
Now, I know that horsetail contains thiaminase, which can cause thiamin deficiency. I'm worried about my goats becoming deficient and possibly dying. I've seen what this deficiency can do to a goat(he didn't eat horsetail, he just had a deficiency), and I would hate to see it again
. I've read some differing opinions concerning the toxicity of horsetail. Some sites say it rarely poisons ruminants, while others say that it poisons all livestock. None of my goats have shown any signs of poisoning or lethargy, but I don't want to take chances.
Has anyone had any personal experience with this?(hint, hint, Goathiker
) Is there anything I can do to eradicate the horsetail? Short of yanking each of them out by the roots of course. Maybe mowing over what I can...and making sure the goats don't eat bunches of it. Or is the only thing I can do is watch the goats and have a vet's number handy? I'll see if I can get some B1 in case of anything, I think I would need to get the injectable from a vet since I can't find any online. Would capsules of human B1 work?
Now, I know that horsetail contains thiaminase, which can cause thiamin deficiency. I'm worried about my goats becoming deficient and possibly dying. I've seen what this deficiency can do to a goat(he didn't eat horsetail, he just had a deficiency), and I would hate to see it again
Has anyone had any personal experience with this?(hint, hint, Goathiker