When Do Snake Shed Their Skins?
The most familiar example of moulting in reptiles is when snakes shed their skins, when they outgrow them. This happens continually, because snakes keep growing throughout their lives, although more slowly as they get older. The skins are discarded at regular intervals of one to three months, according to the variety of snake.
During this process, which is known a sloughing, the old skin is turned back on itself, beginning at the lips and gradually revealing the new skin underneath. When sloughing has ended, the old skin will have been turned completely inside out and left in one piece.
This is usually achieved by the snake rubbing its head against a hard object, such as a rock (or between two rocks) or piece of wood, causing the already stretched skin to split. At this point, the snake continues to rub its skin on objects, causing the end nearest the head to peel back on itself, until the snake is able to crawl out of its skin, effectively turning the moulted skin inside-out.
This is similar to how one might remove a sock from one’s foot by grabbing the open end and pulling it over itself. The snake’s skin is often left in one piece after the moulting process, including the discarded brille (ocular scale), so that the moult is vital for maintaining the animal’s quality of vision. The skins of lizards, in contrast, generally fall off in pieces.
In general, snakes will slough at least once a month. The frequency of shedding depends on many factors: species, age, nutritional and reproductive status, the presence of skin parasites or bacteria, and ambient enclosure temperature and humidity. Generally speaking, younger snakes will shed more frequently than adults and shedding often precedes mating and giving birth. The most common causes of improper or incomplete shedding are related to husbandry and nutrition.
Why are some sheds incomplete?
There are many reasons for the shedding process to be incomplete or improper, referred to as dysecdysis, the most common related to poor husbandry or nutrition. Dysecdysis is a symptom of another problem and not a primary problem in itself. A good rule of thumb is to have your pet snake checked by an experienced reptile veterinarian if you observe an incomplete shed.
This will rule out medically treatable causes such as mites or bacterial infections of the skin. Other causes of dysecdysis include: trauma, dermatitis, malnutrition, and over-handling. Your veterinarian can guide you in appropriate treatments once the underlying cause has been determined.