Urine Issues: Red Urine and Sludge
Rabbits urine varies in color from clear to yellow to brown to bright red. This is usually not a cause for alarm UNLESS there are additional signs such as sitting & straining to urinate, loss of appetite or a temperature. When you see red urine, don’t panic, just keep your eyes open for other signs that might indicate a problem. The red color will usually be gone in a day or two, but can last for a much longer time. If you’re in doubt, your vet can test to see whether or not there is blood in the urine.
Here's a great video on what to watch for in your bunny's pee and poo, including color, sludge, normal poop...get ready to be the hero of your next dinner party!