I have rescued two guinea pigs about a year ago. One is turning 5 and the other 6. I have noticed that even though their litter trained they still have problems with urinating on the fleece. I make sure that their litter is clean at all times and I use care fresh as their litter substance. I've even did an experiment consisting of me putting a peed pad on the ground of their cage, overnight. It seemed that they peed more on the pee pad then the litter, even when it was clean. They don't seem to have any urinary or internal problems at all either. mabye you guess can lend me some tips, I'VE BEEN ASKING ALL WEEK! 


