Had major panic stations today. Was grooming Rudy as he'd got his back end filthy again and I found what i thought was a inch long cut and what looked like dried blood. So i phoned the emergency vets and got him over there asap. The vet checked him out and told me it wasnt a cut and its perfectly normal dip and he had another of the other side of his bits. Apparently the red was dried urine and that it can be really dark in rabbits and can be affected by what they eat. Am thinking i need to get myself a rabbit anatomy book lol. She was really nice though and didnt charge even though a standard Sunday fee is £50. Am just recovering as i got really upset thinking he had injured himself.