Cats front left leg is swollen and missing tooth?

My cat came home tonight and he was limping so i looked at his leg and it is swollen quite large and theirs two wounds on it about a inch apart that look like scratches and hes also missing 2 of his front teeth. What could have happened? He has slight pain be he was stilling using it to walk.

Sounds like a bad fight. The wounds in his legs will have been inflicted by another animal biting or scratching him when they have been wrestling, the teeth have probably been lost when he has bitten down and the other animal has wrenched free. You need to disinfect his leg wounds with hibiscrub, to get rid of germs that might cause an abscess. If the swelling doesnt go down he might already have one, if so dont squeeze it or mess with it as you dont want to burst it, this could cause blood poisoning, he needs antibiotics from a vet. Also check his neck, other limbs and round his eyes for wounds you might not have noticed. He also needs to see a vet about the missing teeth, if the roots are left in there they could also get infected which could be really serious. If he is fighting in this manner, he's probably still a full tom? If so, please consider getting him neutered, once toms start fighting like this they won't stop until you do, and it can get really serious (mine used to get abscesses about twice a month til I got him fixed I think he would have died or been permanently injured if I hadn't). If he is already neutered, it might have been another animal attack i suppose, a dog or a rat? You also need to keep him in until he has healed from these injuries, if he goes out and gets in another fight in his weakened state he will be at a disadvantage and could get hurt worse. Best wishes

He could have gotten into a fight with another cat or he could have been hit by a car. I would take him to the vet. If he's in pain you want to be able to give him something.