Many vet drugs, and even human drugs, are only "officially" approved for one species (i.e. humans or dogs.) But lots of vets and MDs use them "off label" based on experience. For example, one of my vets used a human drug, Mobic, on cats (adjusting the dose of course) because it was one of the few low toxicity anti-inflammatories.

The best bet is ask questions and watch for any adverse reactions.