Hi, I'm Ginny and I have 6 cats inside and two strays that are outside.

My two 8 year old female kitties have a clot of fur ball like on their backs.  They don't like us to touch them.  We are trying olive oil on them and waiting to see if that works.  They are both very large breed cats.

Looks a bit like a mat - hair that has tangled to the point where it can pull on the skin. They are best cut as they can actually cause bleeding. Is there a way you can do that? Maybe you vet can suggest a groomer (or do it).

The olive oil may help - the cats may lick the mat. But it will probably not get rid of it.

I might also double check to make sure it is all hair and not something under their skin.