My cat is an Abyssinian Tabby mix. She's 5 years old going to be 6 on August 12. The question I have is about her skin & coat. Every time I rub her back or scratch between her shoulder blades (her favorite place to be scratched) she starts growling & chewing at her front legs because it itches. I pulled some of the loose hair off of her butt & looked at it. It was dry. It is usually like silk. It was filled with dandruff & FLEA DIRT. :? I know that she doesn't have fleas because she doesn't leave the house let alone my room. She wears a flea collar all year round. I change it out for a new one at the beginning of every month & About three timnes a year we put front line on all of our dogs & cats & our ferret. Why does she have flea dirt? I keep checking her for fleas & I'm not seeing any. Why? HELP!!!