I will gladly torture some puppies if it means that no more dogs are killed after that. The end result is more important than short term “issues”.
I used to have an ethical dilemma about animal testing in medicine but then realised that the animals would have been killed anyways and would have had a shitty life before that, in farms or something. Now, at least their suffering is not in vain.
Ideally, there would be no suffering of any organism, but if push comes to shove, you have to make sacrifices.