lump on tail

[Ruth Edwards]

Blossom has a lump on the top of his tail about the size of a small marble. He's always climbing, jumping, falling and seems like his normal self, possibly a bit less hyperactive than usual though it's hard to tell.
I can't photograph it as it doesn't really show through his long fur. I'm trying to avoid a visit to the vet as I have no money at the moment so I wondered if any of you have seen something like it before.
Cotton had something similar which resolved itself but his tail was always a bit wonky afterwards. I wondered if his climbing and falling activities damaged the tail if he fell on it.

[souffle]

Tail breaks are quite common due to falls however they don't usually present as a lump as such. The usually show as a slightly swollen tail and after healed you can feel a crooked bit it you feel the tail. Can you try and get a pic but if it looks like a tumour or something then he does really need seen