He's always drunk at least 1/3 of his wee. Dip stix is normal rabbit wee - no glucose, alkaline, protein+++. Problem - he's recycling the calcium, gets too cloudy for my liking in hot weather. "Turbid", true "sludge" only x2. Also reluctant to drink water - We've very hard water. tried boiling it, deionized, highland spring (soft), clean catch rain, putting in fruit juice, tried bottle & bowls of various depths. He's a tiny "goatee beard" of a dewlap - gets wet in a bowl, but not in his wee! Also has small molar spurs - can just manage 3 months between dentals. Gets hypomotility easily. I've got the hang of a diet that works with loads of fiber, but stress can set off his tummy too, just the sudden rise of temp from 18C to 21C. Reason for question - if I understood why he drinks his wee, I might be able to give what he wants another way, & reduce turbidity. He needs good hydration with the gut problems, & to prevent obstruction on hard dry deformed poops. It's hot again, he breaths faster & loses water - wees less etc. (do the standard things to keep him cool has his main run out at dawn, & just before dusk), otherwise has freedom of the house. It's reducing risk factors & prevention.