How It Works
Lizards that can drop their tail have "fracture planes" spaced regularly down the length of the tail. These are either between vertebrae or in the middle of each vertebra, depending on the species, and it is at these points where the break can occur. Skin, muscles, blood supply, nerves, and bone separate when the tail is dropped. After it falls to the ground, the tail starts to wiggle and move on the ground, hopefully giving the lizard a chance to escape while the predator is focused on the moving tail.
What Effects It Has
Tail loss, though natural, does cause some issues for the lizard. First, it will generally affect the lizard's sense of balance, and it may have trouble climbing or walking regularly until it adjusts to the lack of a tail. For a lizard that stores fat in its tail, it also results in the loss of critical fat deposits. Juvenile lizards stop growing while the tail is healing and regenerating, and, in adults, the reproductive processes stop. Healing and regenerating the tail also takes a significant amount of energy, or protein, so lizards that have dropped their tail are at a greater threat for nutritional deficiencies. Finally, losing their tail makes a lizard more susceptible to predators, as it no longer has anything to drop if it is caught to give itself time to escape.
What You Should Do
If your lizard drops its tail, there are a number of things that you should do to ensure it recovers as quickly as possible without any complications.
When it happens,
To promote quick healing and regrowth,
If the tail break is incomplete, or if the break was very close to the body, schedule a veterinary appointment as soon as possible. Incomplete tail breaks may require stitches or amputation by your veterinarian, and a break that is close to the body may bleed profusely, requiring stitches to close the wound. A tail that has to be amputated by a veterinarian can still grow back.
What Happens After
As the break heals, you should expect to see the exposed muscle bundles fold over the bone that is showing. The end will dry out, forming a cap over the stump, and then skin will start to grow over that. There will be some swelling initially, but if there is any swelling at the break site that has not gone down within one week, schedule a veterinary appointment.
How You Can Prevent It
Since a lizard can drop its tail even if the tail hasn't been touched, it's important that you take care not to startle your lizard or make it feel threatened. Take time when you first get your lizard to learn how to interact with it and handle it correctly. Never hold your lizard by his tail, and never try to catch him by it. Once your lizard is comfortable with you holding it, you can stroke it down the length of its back and tail to get it used to being touched like that.
Tail loss is natural and very common, and with the proper care, your lizard will quickly recover.