My baby is about 7 years old. For the last 3 days his tail has been limp. I checked for soreness in the actual tail, but it only seems to be painful when I lift it. He also doesn't seem to be sore in the rump or hip area. He is having regular, normal BMs although today he started really howling in pain when he goes. Several years back he got something called "Cold Water Tail" and his tail went limp. This is something different, though, as it has lasted longer and the earlier problem didnt make him cry when he pooped. I have been giving him baby asiprin, but it doesn't seem to help. Any ideas on what might be wrong?