My 7 month old English bulldog seems to have a very sore bum periodically And will not let ANYONE touch his tail and bum area at any cost. I have noticed a sour odour and my other dog seems to be attracted to lick and smell it . I haven’t been able to touch him around or under his tail area since the day I brought him home. I had a local vet try to look at it but 3 clinic workers and the vet had a hard time claiming it was just a little red but didn’t see any major issues…. any adivise?