I have a roughly 3 year old guinea pig (adopted) that has been getting a wet bottom. It has been going on for about 3 weeks now and he is acting completely normal; eating, drinking, playing and annoying his brother but he is almost constantly soaking himself. His stool is not runny and healthy pellet shapes and I can’t find a spot in the cage that is wet that he could be laying in. I gave him a few baths now and the next day he is covered again. It looks like it may be urine but doesn’t smell strong of it. The other piggie has not been getting wet. Again behavior is completely normal and appetite is as strong as ever. They have a never ending supply of Timothy hay, Oxbow pellets and get fresh veggies daily and fruits every other. This is something new for him and he is healthy otherwise.