gippsland water dragon

Question
Hi i bought a gippsland water dragon in Melbourne and noticed that the end of his tail is black and it has a little knob in it, almost as a nipped injury, the end seems to grow longer as he is still a baby( about 12cm in length) his tails tip almost looks like he got frost bite? will it affects his whole tail?

Answer
This is a mysterious ailment that has been termed 'tail rot' by some folks.  It will require treatment--you should have a veterinarian amputate the tail above the black part, making sure that he gets into healthy tissue, and then use antibiotics.  Tail rot can indeed continue to spread upward along the tail, though it doesn't always do so.  It's a good idea to treat this early, as it can cause substantial tail loss if it expands.

The cause is unknown, but theories include an injury to the tail tip, and improper humidity or excessive dryness or wetness.  Some even blame poor air circulation.  The blackened part of the tail is necrotic (dead).