hi about 6 months ago my beardie broke the end of his tail and was only barly hanging on ... worried i rang the vet cause its nearly 350miles from where i live i rang first .. the reptile vet told me he was fine it will fall off in time it happens alot ... and he was right it did and it dont seem to bother him at all it completely covered up and looked fine but now my concern is that from the bottom of his tail moving up it is a darker colour and im not sure what it could be i have rang the vet and he isint in today .. can anyone give me any info till then???

Sounds like tail rot, it usually occurs after trauma, starts at the end of the tail and moves up just like you described. Definitely get him looked at by a vet.