Please Tell Me What to Do

My boyfriend’s roommates have a dog and a cat. the dog is left in the kennel probably 22hrs of everyday. He has a rash on his butt that I think is from the kennel, he isn’t trained, in our city the law is you have to fix your animals by the time they are six months old (neither of them are fixed), the cat is trapped in their bedroom 24/7 and it reeks of cat pee. They just got their dog a shock collar to make him behave because when he is outside the kennel he is so rambunctious because he is in there all the time and not trained. They even feed him in the kennel. They only bring the cat out of the room to make it get scared by the dog cause they think it is funny. whenever the cat is downstairs they will not put her down or do anything on her own. Neither animals are spayed or neutered and they have not once taken them to get shots since they moved in with my boyfriend last march. I really don’t know what to do. It is hard to watch and I have debated calling peta, law enforcement, taking them to the humane society, etc. The problem is I would rather it be anonymous because I really don’t want to cause a rift between them because they still have eight months on the lease. Please give advice and opinions. I try to spend whatever days both of them aren’t there to take him on walks and let him run around the house and play with him but it’s so rare that it happens that it really doesn’t help. I don’t know how to fix. I have to talked to them abd begged them to take care of their animals and they truly think how they treat them is perfectly fine.

Update: Bf and I have talked to them ab every expectation for the dog and cat and told them they have until Friday to fix everything and have a new routine or we were going to call them into the authorities/take or send them to the humane society. they tried to argue but we basically said it’s non negotiable and these are the demands or they absolutely will be taken away. we also used the lease against them and also threatened to kick them off and have someone else sign on in their place if they didn’t take better care of the animals. thank you guys so much for all the help, we have written everything formally and gathered evidence and they know we are willing to email/call at any second. i will update if they don’t and we do take further action. i really doubt they will consistently fix it but bf wanted to give them one more chance.