hi, new here, just looking for some advice. i have a 2 year old rescued guinea pig named oswald, and he has been concerning me for he past hour or so. he's never had any health issues or concerns prior. when he's eating his hay, not when eating pepper or anything else, he makes a sort of low pitched rattling sound. he did it once relatively loudly, and then the next few times he ate he made it quietly, or hardly at all. it isn't consistent. it isn't hoarse or weak at all, it's just very low. he's been laying a lot, but i can't really tell if it's anything more than usual. the sound has really made me frantic, he's my baby and i'm very alert with him. he's been eating and drinking and he has a vet appointment scheduled for tomorrow. he looks fine, but i'm so concerned i can't really tell what's serious and what isn't. anybody have any similar experiences?