Self inflicted injury

Question
my male mouse used to live with another male until the other became dominant and bullied my mouse. we separated them and kept their cages side by side, and now my mouse has started to bite his own tail repeatedly. what should i do? and should i take him to the vet?

Answer
Hi Donna,

Are you positive it's him biting his own tail?  When two fighting males are in cages side by side the can and will chew on each others tails through the bars.  If their tails can reach - this is what I would think was happening.  Try separating the cages by at least a foot; you will see both of them calm down (being close to another male can be very intimidating and cause them to be under constant stress - which could even cause the self-destruction if it WAS him doing it to his own tail) and that tail shouldn't have any more problems.  Check if you can to see when he nibbles on it if he's really doing the damage or is just cleaning it and removing dying tissue.

A professional vet is an excellent idea any time a mouse is hurt or sick, especially since tail injuries can be a serious way to get an infection.  The vet will likely prescribe you a good antibiotic, depending on the extent of the damage, and show you how to keep the tail clean and disinfected.  Provided there is no nasty infection, and as long as he is removed from his arch nemesis, it should heal up just fine.

Best of luck, and I hope his tail feels better!
-Tam