Sounds strange, but it could actually be urine... rabbits urinate in a veritable rainbow of colors, including blood red.
In fact, just the other day, we went out to take care of the bunnies, and noticed that a massacre had occurred outside the rabbitry. Then we discovered it was on the inside of the plastic, not the outside, as it appeared. It turned out that our buck, thankfully not known for spraying, had decided to do so overnight -- in blood red, across the plastic covering the front of the rabbitry some 4 or 5 feet away from him. :roll: <br /><br /> __________ Thu Feb 06, 2014 1:33 pm __________ <br /><br /> Rabbits usually pee in colors ranging from beige to yellow to brown, but orange and red are rather common. Less common is green and purple. I think I've seen one mention of each. I haven't heard of blue urine from a rabbit, but at this point, it would not surprise me.