need help with a sore on my cat's side

Hi guys. I have a cat that has a sore on her right side about the size of a nickel. It started as a dry hard spot that is now oozing and looks like there is a hole kind of. She is an inside cat only and she isn't acting like it bothers her At all. Any ideas as to what it could be?

@alliecat31

It looks like a bite wound or possibly an abcess that has burst. It reminds me of possibly a cuterebra worm, but you said she is inside only. Can you look inside the hole and see if you see anything in there like a worm or anything sticking out abnormally? You'll need to see a Vet to have it cleaned and also treated. You'll probably need antibiotics for her as well.