There are caveats. In order to be considered ethical - same preclinical work must be done, same proving of safety for first in-human use. When in-human phI reached - same informed consent practices and safety monitoring must be used. The international trial standards include everything we're used to here. The companies that have not used them and try to get there product thru fda or ema are sent back to drawing board - so pharma has learned not to try for shortcuts. Pharm has in past been caught rushing agents into human trial without adequate preclinical safety proof - that's why strict standards exist - to protect the poor in countries where they have no voice and could be subject to such abuses. and to protect those that live in wealthier nations from inadequately tested agents.
So - if company follows same safety criteria that they would here - they're fine to use that work for US approval. It often takes longer to fulfill recruitment in other countries though. Initially looks cheaper but extended time to fill cohorts often ends up costing companies more. Less organized and often smaller research hospital networks mean less effective recruiting and follow-up.
Your dog antibiotics were the same as the ones in my cabinet ordered by gp.