Aster, my youngest guinea pig, started breathing weirdly a few days ago. His breathing isn't popping when he takes in a breath but his whole stomach is kind of convulsing every time he breathes. He's still eating (veggies, pellets, and hay) and drinking water. He's also still pooping but his poops are oldly skinny and small. He used to be my most active guinea and now he just lays in the sun all day. I noticed yesterday that he tried to avoid at all cost getting on his hind legs to eat the pellets (which tells me that his stomach must hurt because he doesn't want to stretch it out). Mika, another one of my guineas, had similiar symptoms around that same age and I took him to a vet. The vet said Mika was perfectly healthy and only to worry if he stops eating. That's the only reason I haven't taken Aster yet. He's still eating so it must just be a cold or something. My question is does anyone know what is wrong with him? Is it his lungs or stomach? Also are there any natural remedies to help him?