my cat is 12 years old (domestic shorthair). i don't know if i should be worried about this or not. she's been shedding a lot, like tons. but it hasn't been just this season or something it's been going on a while. she doesn't have any bald spots but she does have this dandruff type stuff on her skin. it also comes out in clumps, like i can tell if i can pull it out because it's turned a brownish color. just recently i pulled out a huge amount of hair. i mean it's really gross. is it because she's getting older or what? 
