I got my first guinea pig today and I’m quite obsessed! The girl I got him from had clean water and stuff in his cage, but he is rather skinny and I can feel most of his joints/bones. I have only had him a few hours, but he is very active and eats/drinks well. My question is how can I fatten him up healthily, and could it be because she just wasn’t feeding him a proper diet? I only seen dry pellets there by his cage so I’m guessing that’s what he got daily.