Just discovered the Pet bit on Mumsnet! We got a guinea pig in November, we live in France and were told that you have to give a liquid vitamin C supplement in their drinking water every day. I get the impression that he doesn't like the water with the drops in plus it makes the water bottle go a bit manky (film develops on the inside, even when changing the water daily), so I stopped giving it. In all the English books and UK websites I've looked at, I've never seen this recommendation...I'd appreciate any experienced GP owners' thoughts! Thanks!