Caudal autotomy is the official medical name for what occurs when a lizard sheds or drops part of its tail. Lizards drop their tails as a defense mechanism when they feel threatened by a predator. The loss of the tail is intended to distract and confuse the predator, which in turn allows the lizard to escape the threat. Quite a few different lizard species are capable of caudal autotomy.
Shedding the Tail
Lizards only shed their tails under extreme distress. The actual tail loss occurs at the site of fracture planes, which are naturally located throughout the length of the tail. Most lizards have fracture planes either between their vertebrae or in the middle of the vertebrae. When the lizard drops its tail, the fracture plane severs the body's connection with the skin, muscle, nerves, blood supply and bone in the tail. The tail will fall off of the lizard's body and then continue to twitch and wiggle on its own for several minutes.
It is normal for the tail to bleed slightly when it detaches from the body. The sudden loss of contact between the body of the lizard and the tail means that blood will still flow slightly for a minute and you may see pink, exposed flesh and body fluids immediately after the tail has been dropped. This occurs regularly in the natural environment and your lizard should not suffer any long-term ill effects as the result of dropping his tail.
Heavy bleeding is not normal after your lizard loses his tail and it can be a sign that something is wrong with your lizard. If the tail has been pulled off by poor handling or a predator, then you may see significant bleeding because the lizard's body was not prepared to lose the tail. You may also come across a tail that did not detach correctly or only detached partially. Bleeding that consists of more than just a few drops of visible blood or slight oozing needs immediate veterinary attention. Any significant blood flow will need to be staunched as quickly as possible and treated by the veterinarian.
Your lizard will be slower and less balanced immediately after the loss of his tail and for the period of time when his tail is growing back. Keep potential predators away from your lizard while he heals. Keep his living enclosure as clean as possible with minimal dirt, trash or fecal matter present. Discuss your lizard's after care with your veterinarian to see if you need to use a disinfectant or antibacterial medicine on your lizard's tail stump until it heals over.
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