huge round sore on cat

Question
My boyfriend's cat has a huge round open sore on her side--i just saw it last night--he says its been there for over a month (OMG!!) and bleeding everywhere (she's an outdoor cat, a bit on the wild side) I caught her last night and bandaged it up as best i could but...its perfectly round--about two inches in diameter and just looks awful.  I looked in the previously asked questions and saw the ringworm pics but...it doesn't look anything like that...this is a raw and open --i'd appreicate any help or advice mahalo

Answer
Hi Amy.  My goodness!  Unfortunately, there are a lot of possibilities, ranging from cancer to a parasitic infection, and the kitty really needs to see a vet.  The lymph and blood in cancerous tumors can ulcerate through the skin.  Abscesses will, too.  This time of year, we see an increase of parasitic infestations such as Myiasis (maggots) and Bot fly larvae in cats.  Both can leave infected wounds once they leave their host.  Some cats develop large lesions on their skin called eosinophilic granulomas or plaques, and these are caused by their own immune systems (though these don't typically bleed much).  There is also the possibility that she was attacked by something, and the wound is too large to have healed on its own.  And many more possibilities still.  I hope it's something that the vet can fix up and have her feeling better in no time!

Jessica