Allergies
 

I believe my cat has allergies, due to the excessive washing she does to her hind legs. She also seems to scratch a lot for a cat without flees.

How can one try and figure out what the cause is?

A single flea can cause a reaction - and fleas don't often stay on an animal very long - so don't rule out an allergic reaction to fleas! If you look real carefully, can you find tiny black specks anywhere on her skin or in her fur? That would be a sign of fleas - if she's an inside cat, they're pretty easy to control.

If you see any redness or scaliness (anything that looks like the skin might be irritated) on her, it could be any number of things that would need to be determined by a vet.

You might want to check this site:
[url]http://www.vetinfo4cats.com/catskin.html[/url]