sores on cat

Question
QUESTION: I have an old black and white boy kitty who has been getting deep(no drainage to speak of) crater-type sores that appear randomly on his body and heal up within two weeks or so. He usually only has one at a time and there is no hair-loss associated with the sore. This started a few months ago with one or two, took a break for a month and we thought it was gone and now he has had two more. He is not overly bothered by them and doesn't lick them much. What could this be?

ANSWER: There are many reasons for this type of skin lesion and the best way to know what this is would be to have your vet do a skin biopsy when there is an active lesion to be sure.  Some foreign bodies can do that as well as some of the deep skin fungi.

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QUESTION: I had an appt so took him to the vet prior to receiving your answer. The vet took no biopsy and told me he was getting in fights, gave me an oral antibiotic to give him and some granualar? topical gel-type stuff. She said she didnt know of any infections that would cause a complete opening of the skin down to the muscle layer like the lesions do.  She is a general vet not a skin expert and there is no way this comes from getting in fights, which he doesn't do anyway. This starts like a round boil and then opens up to the muscle.  My question now is what do you mean by foreign bodies? Parasites or ? Being that my vet knows of nothing that would cause this, does that mean when I tell them I want a biopsy for fungi or foreign bodies are they gonna be able to do that you think? The more specific I can be with them the larger the chance they can track this down for the least amount of money. He is such a smart wonderful cat. He's the best cat I ever had and I have had a quite a few. I wish my funds were limitless for this but they aren't. Thanks for helping, Dr Gotthelf.

Answer
Does this cat root with its nose...putting the nose under things and pushing up? Anything can be a foreign body including an in grown hair.  Things like plant material, thorns, anything sharp can be the culprit.  There are special stains that the pathologists use to determine if there are fungi or bacteria present.