Merck Manual

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Selecting a Reptile


Roger J. Klingenberg


Last full review/revision Jul 2011 | Content last modified Nov 2016
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When choosing a pet reptile, it is important to have a clear understanding of both the care required for a particular species and the level of companionship you expect from a pet. Even though reptiles might seem like inactive “couch potatoes,” keeping them as pets takes just as much of a commitment as caring for other, more assertively demanding companions such as birds or dogs. However, some species of reptiles require less effort and money to feed, house, and adequately care for over their life span than others.


Average Life Span of Reptiles in Captivity

Ball python

15 to 20 years

Boa constrictor

15 to 25 years

Bearded dragon

5 to 10 years

Corn snake

10 to 15 years

Eastern box turtle

25 to 50 years

Green anole

4 to 8 years

Green iguana

5 to 15 years

King snake

10 to 15 years

Leopard gecko

20+ years

Leopard tortoise

50+ years

Old World chameleons

3 to 8 years

Proper habitat is of the highest importance. If you are buying a tiny hatchling, make sure that you have enough space in your home to accommodate the cage of the fully grown reptile. Consider the type of food the animal will eat—feeding a frozen mouse to a pet snake is not usually for the squeamish, and the crickets that the leopard gecko has not yet eaten will be noisy. In general, reptiles are not social creatures or colony animals. Many prefer to live in solitary cages. A few species, such as green iguanas, bearded dragons, box turtles, king snakes, and boa constrictors, are more open to being handled, and they might even approach their human companions. Others, such as chameleons, are more likely to be stressed when touched or picked up. Finally, unlike some other pets that live in enclosures (such as mice and hamsters), reptiles have rather long life spans. Consider the number of years that you will be willing to maintain and enlarge the reptile’s habitat (see Table: Average Life Span of Reptiles in Captivity). Never release a pet reptile into the wild, even if the species is native to your area; instead, contact the local humane society or animal control agency.

It is important to know what is normal for a reptile before visiting the pet store or breeder. Look at a variety of pictures of your chosen reptile as a juvenile so that you can select one with a healthy size and appearance for its age. Choose a pet store or breeder whose reptile enclosures are clean and large enough to keep the inhabitants healthy and comfortable (see Providing a Home for a Reptile). Captive-bred animals make the best pets. They are less likely to bite than wild-caught animals, more likely to accept the food given to them, and less likely to harbor parasites.


Healthy young snakes should have a rounded body, clear eyes, and a clean vent. Their spine should not stick out. Snakes should not wheeze or have mucus or bubbles near their nostrils. They should have no apparent skin cuts or parasite infestations. Choose a snake that flicks its tongue and is aware of and interested in its environment. When handled, the snake should seem to have strong muscles and lightly squeeze your hand or arm. Avoid nervous snakes that do not calm down after a bit of handling.

If you are a first-time snake owner, check with a reputable pet store regarding recommended species for beginners. Also, it is wise to check any local laws regarding snake ownership; for example, keeping constricting snakes such as pythons is prohibited in many areas.


Well-nourished, healthy lizards should not have projecting hip bones or visible tail bones. Their skin should not be scratched or bitten. The vent area should not be stained with urine or caked with feces. Eyes and nostrils should not be swollen, crusted, or show signs of discharge. However, it is normal for some species to have light salty deposits near their nostrils. Most species should have a pink interior mouth; yellow, white, or green spots in the mouth or on the tongue can indicate illness. Look for signs of mite infestation: tiny black, brown, reddish, or orange flecks that move on the head, neck, and belly. Even though this is fairly easy to treat, it can be a sign of unsanitary conditions. When handled, healthy lizards should seem strong. Most lizards will probably resist being caught or struggle. Tame lizards will be wide-eyed and alert when handled. Avoid lizards that are limp or unresponsive. Cool conditions can cause short-term sluggishness, but such habitats can lead to overall poor health.

If you are a first-time lizard owner, check with a reputable pet store regarding recommended species for beginners. Some lizards require more complex environments than others; also, some lizards can be handled frequently while others should be left alone for the most part.

Turtles and Tortoises

A healthy turtle or tortoise will have clear eyes and dry (not moist) skin without any wounds or evidence of parasites. The shell should not have any white or “weeping” areas or any evidence of erosion or previous damage. The animal should not wheeze or have mucus or bubbles near its nostrils. Any droppings in the enclosure should be firm and not liquid. Runny feces may be a sign of disease caused by parasites. Captive-bred turtles or tortoises often tend to be healthier than those that are caught in the wild.

All turtles and tortoises with top shells less than 4 inches long are illegal to sell as pets in the US. This law was created in 1975 in the interest of public health: the popularity of keeping baby turtles as pets had led to more than 250,000 Salmonella infections in infants and children. (The reasoning behind the size restriction is that turtles larger than 4 inches are less likely to be kept and handled by children.) Nevertheless, baby turtles are still bought and sold as pets, especially in tourist areas. However, even baby turtles that are certified as free from Salmonella are illegal to sell in the US because of the risk of later infection.

Turtles and tortoises have complex housing and environmental needs. Although some species might be adorable as hatchlings, they grow quickly and are quite messy. They do not remain small if kept in a small container. Small fishbowl-type tanks are not adequate for housing turtles of any age or size.

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