My son is looking up pictures of furry pornography (yiff)... I just want some opinions, please?

My son is 15 going on 16 next year... (it still scares me how fast the boy is growing). I was deleting the browsing history and cookies earlier today and came across a term I wasn't familiar with, so I clicked on it. It was Lucario of something--honestly thought it was a disease at first. I'm sure it was my son, because I don't think any of his friends look up things on the internet at 3:00 AM on the weekends. Anyway.. The images I've found of this anthropomorphic pornography is a tad disturbing to me. I'm not sure of what he would be attracted to in animals. I know he's probably attracted to them because there are a lot of them in the history. From multiple different times, even a month ago. Does this lead to zoophilia? I want to hear from both sides, also. I am aware that there are people called 'furries' out there, I'd like to hear from them about how this community and these pictures effect one's life. I don't mind hearing from other people as well, but I want multiple perspectives to judge from. I'm not punishing him, I haven't even talked to him about it yet. I don't know if I should, but I just personally want to know how this is going to effect him. I'm just curious, maybe a little worried. Thanks for the help.