I think my cat may have got bit by a Brown Recluse Spider

Question

Right leg bite mark  

Again   I am very worried about my 7 month old cat ninja . We had let him outside to play he is a inside/outside cat. My mother in law had said that he had got in a cat fight with a neighborhood cat. So we blow it off he back leg was seeming like it was hurting him we gave him some cat pain meds and he was fine . Until the other night my husband went to get home and when he put him down he had blood on him. I check him over and couldn't find another so I was like ok maybe it wasn't ninja (my cat). But tonight when I got off work I was looking at him and he didn't seems the same he was being lazy and he hasn't are anything but still drinks water. But he has a like a bit mark on his right leg and I'm very worried about it I have read website after website and they all say it may be a spider bite. Can you please help me I have pictures of it

Thank you

Answer
This is more likely to be a cat fight abscess than a spider bite.  When cats fight, the sharp nails penetrate the skin and seed it with bacteria.  After several days, pus and blood come in to kill the bacteria and the pressure causes the skin to open releasing bloody pus.  That also causes pain and fever.