Check product literature and with Vet. As you said, do not use bovine products on equines.
For example, Ivermectrin (by variety of trade names) is generally a multipurpose de-wormer (according to what I've read on product labels); however, dosage varies significantly across species. Judging from usual higher cost of equine products, I would think that bovine products for cattle would be cheaper and safer.
As a lot of prudent advice I've heard over the years on things, "if in doubt, don't do it."
:cboy:
