If zoophilia is your sexual orientation, stopping might be extremely difficult. I used to know someone who stopped because of another very powerful reason, their religion. Eventually they came to the conclusion that their god actually wants them to be zoo. Of course, because in reality they simply could not resist and needed an excuse.
If you are just addicted to porn, stopping might be a bit more simple.
stopped what? smoking? drugs?
like pes said, porn addiction, don't ever go into anther porn site
if your truly zoo and think you can walk away from it ..... never gonna happen ...easier in this day and age to change your sex then to stop loving animals, sex is just a bonus we like when available, but you can live without it.