First off I do have to say my guinea pig is quite old, she's around 7 years old. For the past little while she's become very skinny and lethargic but she's still very ravenous when food or treats are coming..the only problem is, she doesn't chew properly, not the way she used to atleast or like her cage mate, she takes a small bite, nibbles on it a bit and actually spits it out but goes crazy when the actual food is in my hand but wont take a bite! She doesn't eat her pellets very much but what I've been doing is making the pellets into a mush and she goes crazy for that and manages to swallow that. Cucumbers are her favourite and she takes a small bite and simply lets it fall out and goes back for more just to repeat the process. I've never seen a guinea pig do this before, I'm not entirely sure whats wrong...could it be a blockage? a hair ball? I've never seen a guinea so skinny.