These days, everyone hates Testing on Animals for consmetics. The vast majority thinks animal testing of medicines for use on humans is OK. But what about medicines for animals? Should animals be tested on (with a minimum of suffering) so that Fluffy can get his yearly 'flu shot? But then surely a few suffering in tests is better than thousands suffering and dying?
Of course this brings up another issue. While the money is in Fluffy's healthcare, the wrong disease in working animals in the third world could be a disaster for the human populations.