Today I noticed my cats fur felt weird on his neck, closer inspection I have found he has a giant wound there that is recent. He will not stop scratching here, so I think the wound is from him scratching it. He's also missing a huge chunk of hair here. I took a picture and it looks pretty disturbing, not sure what it could be. I can't get him to a vet until Monday, so any suggestions are welcome. I should also mention he was in a cat fight about 2 weeks ago that was pretty bad, I took him to a vet after and they gave him antibiotics that lasted 2 weeks. Since then, he has not gone outside at all.