Owning Box Turtles

By Laurie Hess, DVM; Rick Axelson, DVM

General information

Several species of turtles are available for purchase as pets. By far the most common species of pet turtle is the popular box turtle. If you own another species of turtle, most of this information will apply, but you should check with your veterinarian about any specific requirements for your specific pet turtle.

Box turtles can make great pets if cared for properly. Before bringing any pet – reptile or other - home, be sure to do research to learn about its requirements, so that you can properly care for it.

Most box turtles do not get very large (unlike tortoises). The average adult size of a box turtle is roughly 5-7 inches (13-18 cm) in diameter, with females being slightly smaller than males. If well fed and cared for properly, this adult size is reached by 4-6 years of age. As hibernation slows down growth and metabolism, pet turtles that are not allowed to hibernate grow at a faster rate. Sexual maturity is reached in about the fifth year of life. With proper diet and housing, captive box turtles usually live up to 20 years of age, but some have been reported to live 30-40 years.

Is infection with Salmonella bacteria a concern with box turtles?

Turtles are commonly incriminated as a cause of Salmonella bacterial infection in children. Salmonellosis is a zoonotic disease, meaning it can be transmitted from animals to humans. Infected animals and people carry the bacteria in their gastrointestinal tracts and shed the bacteria in their feces, serving as a source of infection to others. In susceptible people and animals, salmonellosis can cause severe gastrointestinal disease, with symptoms such as nausea, vomiting, diarrhea, abdominal pain, cramping, fever, or septicemia (blood infection). Young children, the elderly, and the immunocompromised are most at risk for developing severe disease. Although turtles are certainly not the only reptiles that can carry Salmonella, most turtles carry the infection asymptomatically, in that they do not show signs of illness.

"Salmonellosis is a zoonotic disease, meaning it can be transmitted from animals to humans."

During the mid-1970s, some young children contracted Salmonella from their pet turtles. Many of these children did not exercise proper hygiene (such as washing their hands after handling the turtles and even placing the turtles in their mouths). Legislation was then passed in the United States making it illegal to sell turtles with a shell length smaller than 4 inches (10 cm) to try to prevent children from putting small turtles into their mouths. Before purchasing a turtle, check the laws in your municipality regarding legal ownership of pet turtles.

Prevention, through proper hygiene, is the best way to prevent salmonellosis. Properly clean and disinfect the turtle’s tank every time it is soiled. Clean up all feces right away. Have a dedicated area for cleaning reptiles’ items, separate from the area humans’ items are cleaned. Most importantly, wash your hands thoroughly with disinfectant soap every time after handling, feeding your turtle, or cleaning its cage items to help minimize risks of contracting salmonellosis. Since most turtles that carry Salmonella are not ill, they usually require no treatment.


How do turtles differ anatomically from other pets?

The most obvious difference between turtles and other animals is that turtles have protective shells that replace many of the bones, such as the ribs, that other animals have. The top, or dorsal shell is called the carapace, and the bottom, or ventral shell is called the plastron. The shell is covered with bony plates called scutes. The scutes are usually shed in large patches, unlike the scales in snakes, which usually are shed in the snake’s skin all in one piece. The numbers of scutes, or the "rings" on the scutes, have nothing to do with the turtle's age.

"The most obvious difference between turtles and other animals is that turtles have protective shells that replace many of the bones (such as the ribs) that other animals have."

Turtles have strong leg and neck muscles that enable them to retract their limbs and head into their shells when they are disturbed or stressed. This retraction process is one of the signs of a healthy turtle that you should observe if you are considering purchasing or adopting one. In addition, turtles lack teeth but have a strong beak that they use in biting.

Unlike mammals, turtles have no diaphragm muscle separating their chest and abdominal cavities; they draw air into and out of their lungs, or breathe, by movements of membranes enclosing their internal organs and by movements of their legs and head. Also, unlike mammals (including cats, dogs, and people) that have a four-chambered heart, turtles have a three-chambered heart.

Another difference between mammals and turtles is that turtles have a renal portal blood system, meaning they have a special set of blood vessels that takes blood from the hind limbs and filters it through the kidneys before returning the blood back into the general circulation. This means that toxins from the rear limbs (as could occur from bacteria in wounds on the legs), as well as drugs injected into the rear legs, would be filtered out by the kidneys and would not enter the general circulation. This is significant when antibiotics or other injections are administered to turtles. Injections should be given only in the front legs and not the back legs, or they may be removed from the bloodstream by this renal portal circulation before reaching key organs in the body.

Unlike mammals that excrete urea (liquid urine) as the main waste byproduct of protein metabolism, box turtles and many other reptiles try to conserve water by excreting uric acid (solid urine), thereby allowing them to adapt to desert environments where water supply might be restricted. In addition, turtles, unlike some other reptiles but like mammals, have a urinary bladder.

Finally, unlike mammals, turtles have a cloaca, which is the common space inside the hind end of the turtle’s body into which the urinary, gastrointestinal, and reproductive systems all empty. Feces and urine that accumulate in the cloaca is voided externally to the outside through the vent (common opening on the underside of the tail for emptying of the digestive, urinary, and reproductive tracts).

Is there any difference in appearance between the sexes in turtles?

In general, males have a more concave plastron than females. This concavity allows for easier mounting of the male on the female for mating. Males are also slightly larger than females. Having a male and female next to each other makes the comparison easier. Males also usually have longer and thicker tails, which once again facilitates easier maneuvering during mating. Also, the distance between the vent and the back edge of the shell is greater in males. Finally, males have red irises, while females have yellow-brown irises.

How do I select a box turtle?

Most owners buy turtles from local pet stores or breeders. Young, captive-raised animals make the best pets, as they tend to be healthier and bond more readily with their owners. Older, imported animals may harbor internal parasites and often suffer from the stress of captivity.

Start out right with a healthy pet. Avoid purchasing or adopting box turtles that have sunken or closed eyes, have any type of discharge coming from the nostrils or eyes, or appear inactive or lethargic. Eyes that are sunken into the head or swollen shut often indicate dehydration, emaciation, starvation, and/or vitamin A deficiency. A healthy turtle is usually active and alert, feels "heavy," and retracts its head and limbs into its shell when handled. Make sure the shell is smooth and is not cracked, pitted, missing scutes or has any obvious signs of infection (such as shell discoloration or moldy growth). The shell should be hard; a soft shell is a sign of disease. The vent should be clean and free of accumulated stool. If you can gently open the mouth (difficult or impossible to do in most turtles), there should be a small amount of clear saliva present, and the lining of the mouth should be pink. Mucus that is stringy, bloody, or "cottage cheese"-like may be a sign of a mouth infection, as is redness or pinpoint hemorrhages on the mucous membranes lining the inside of the mouth. Finally, when purchasing a turtle, always inquire about the guarantee in case the turtle ends up being unhealthy.


My turtle looks healthy. Why does he need to see the veterinarian?

Within 48 hours of your purchase or adoption of a new turtle, your new pet should be examined by a veterinarian familiar with reptiles. The veterinarian should perform a thorough physical examination, including measuring the animal's weight, and should examine the animal for signs of dehydration or malnutrition. A fecal test should be run to check for gastrointestinal parasites. Some veterinarians routinely deworm all new pet turtles for parasites. Your veterinarian also should examine the turtle’s mouth for signs of infectious stomatitis (mouth infection, or “mouth rot”) and feel its abdomen (for organ swelling or abnormal masses) by palpating just in front of the turtle’s hind legs, beneath its shell. Your veterinarian may recommend blood tests, cultures, or radiographs (X-rays) to check for other diseases. Typically, no vaccines are required for turtles.

"Within 48 hours of your purchase or adoption of a new turtle, your new pet should be examined by a veterinarian familiar with reptiles."

Like all pets, turtles should be examined at least annually and should have their feces tested for parasites at every examination. In captivity, turtles’ toenails may need to be clipped periodically; your veterinarian can do this for you or show you how to during one of your routine visits.

Remember, thoroughly wash your hands after feeding, cleaning, or handling turtles to minimize risk of contracting a Salmonella infection.

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