So irresponsible and ignorant . I don't understand why he would have a pet when he dosent even care for it in the first place. I felt bad for the cat. I don't have any knowledge about cats but I think it's best bring it to the vet . Besides the cat have an infected claw so imagine how dangerous it would be if let's say the cat accidentally scratch someone or anything the person might be affected too .. I hope that your boyfriend's roommate will take it seriously and start to take responsibility over it .

If there's a pet service (police-ish), tell him you're going to report him for animal abuse. And if nothing happens, report him. The cat is miserable, poor thing. Not only has it been restricted from what it knows (outdoors) but it's also sick.
The spraying can be dealt with. But it's obvious the cat is unhappy to me. But yeah, I would probably report him for animal abuse and if the pet is not taking from him, try contacting shelters to see if they can take him and perhaps also take care of the vet bills (despite it not being your cat). If all else goes wrong, I would probably take the cat to the vet and get it euthanized (unless that goes against law, don't become a criminal). I don't think living with your boyfriend's roommate is an ideal life at all, it sounds like pure neglect. All animals deserve another chance, but this guy most certainly does not.

first of all if he used to be outdoor keep him outdoor, getting him neutered (u said spayed u just called him a she omg) will not stop him from spraying. you can buy medicine for the animal, if I would see the wound I could best tell you what to do, but ultimately he needs a vet if he has an infection so it can get an antibiotic shot, and the best thing for everyone involved is to put the damn thing back outside where he's made his living like if a cat is raised outside taking him away from that beyond the age where he begins spraying will lower his lifespan

Have u tried to clean the scar with sone medicine?? Since we lived in different country. I dont think we have the same medicine brand. So, just try to google.
But u need to look ask the pharmacy what kind of medicines good for pet also. I used to give. Y pet a medicine called betadine when my cat fight with others and his feet was hurt that made it bigger. We gave him tht medicine but not too often. Bcs cats normally have sth in his drool (or whatever it is in English) when he their own scar to make it better.