Hi, I'm new and this is my first post and unfortunately I need some advice.

We have two female moggies (siblings). One is a typical bossy lump, and the other bless her was the runt of the litter. They are nearly 4 now and up till recently we have never had any problems.

One of them is now biting and chewing her tail till it bleeds near the base. It happened a few months ago, and I thought it possibly FAD, so we changed to frontline and took a trip to the vets. The vet cleared her bum glands and suggested this more likely the cause of the biting.

Things seemed fairly clear, until this morning when she turned up covered in blood. On a closer look, she has made a real mess of her tail around the same place again. It was a shock to see her come back like that. She also appears to be sitting uncomfortably and even prefering to drop to her side rather than sit straight down.

It looks like another trip to the vet for her, but I was just wondering if anyone could offer any general advice. We were wondering about altering her diet, but they already eat dried food so would have hoped they're getting plenty of fibre..

Any advice greatly appreciated.