I just realized that the feed that my daughter is using for her sheep contains Lasalocid, which is a coccidiostat. Her lambs have a paddock to graze and are intended to be show and breeding animals.
My ignorant first reaction to the Lasalocid is somewhat negative. First, it's highly toxic to horses, so I'm not thrilled about having it on the place, though we are already very very careful about keeping the feed separate and secured. (I know that the horse feeds are also toxic to sheep because of the copper content.) Second, I'm not a fan of medicated feeds without reason, and I'm not sure we have a reason here.
I clearly need to find The Chronicle of the Sheep BBS. Is there such a thing?
I didn't find a lot of info on this via google, to my surprise. It seems to be pretty standard.
If you are allergic to a thing, it is best not to put that thing in your mouth, particularly if the thing is cats. - Lemony Snicket
There are many different coccidiostats that can be mixed in with sheep feed besides lasalocid. I agree, it is a potential set up for disaster if someone should accidentally mix up the feeds or should a horse somehow get into the sheep feed.
Talk to the feed suppliers in your area. I'd look for a feed that has decoquinate, which is, I believe, fairly non-toxic to horses. Alternatively you can have a feed mill custom mix you some sheep feed that does not include a coccidiostat.