Owning Box Turtles

By Gregory Rich, DVM; Laurie Hess, DVM; Rick Axelson, DVM

General Information

By far the most common species of pet turtle is the popular box turtle. There are four subspecies of the common box turtle that are available to buy at pet stores: the eastern box turtle (Terrapene carolina carolina), the three-toed box turtle (Terrapene carolina triunguis), the Gulf Coast box turtle (Terrapene carolina major), and the ornate box turtle (Terrapene ornata). The ornate box turtle is the smallest and has a shorter lifespan.

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 home, be sure to research its dietary and housing requirements. Box turtles are omnivorous, meaning they eat both plant and animal-based foods. Proper knowledge about diet, housing, and health issues before you acquire a box turtle will help prepare you and your new turtle for a long, healthy relationship.

"With proper diet and housing, captive box turtles usually live up to 20 years, but some have been reported to live 30 to 40 years."

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

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 immunocompromised humans are most at risk of developing severe and sometimes fatal disease from Salmonella bacteria.

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 where human items are cleaned. Most importantly, wash your hands thoroughly with disinfectant soap after handling your turtle, feeding your turtle, or cleaning its cage items. Since most turtles that carry Salmonella bacteria are not clinically 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 that other animals have, such as the ribs. The top, or dorsal, shell is called the carapace, and the bottom, or ventral, shell is called the plastron

Box turtles have a hinged shell that can close tightly, enclosing the head and front legs behind the front hinge. The shell is covered with bony plates called scutes. The scutes are usually shed in large patches, unlike the scales in snakes, which shed their skin all in one piece. The number of scutes, or the “rings” on the scutes, have nothing to do with the turtle’s age.

Turtles have strong leg and neck muscles that let them 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 look for when 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."

Unlike mammals, turtles have no diaphragm muscle separating their chest and abdominal cavities. They breathe (draw air into and out of their lungs) through movements of membranes enclosing their internal organs and by movements of their legs and head. Also, unlike mammals, which 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 take 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 general circulation.

This difference is significant when antibiotics or other injections are administered to turtles. Injections should be given only in the front 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 conserve water by excreting uric acid (solid urine), thereby allowing them to adapt to desert environments where water supply might be restricted. Interestingly, turtles have a urinary bladder like mammals but unlike some other reptiles.

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 are voided to the outside through the vent (an opening on the underside of the tail).

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

In general, males have a more concave plastron than females. This concavity allows the male to more easily mount the female for mating. Males are slightly larger than females and usually have longer and thicker tails, which facilitates easier maneuvering during mating. Also, the distance between the vent and the back edge of the shell is greater in males. Finally, male box turtles 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 intestinal parasites and often suffer from the stress of captivity.

"Young, captive-raised animals make the best pets, as they tend to be healthier and bond more readily with their owners."

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 not cracked, pitted, missing scutes, or shows 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. Mucoid discharge from the mouth or nasal passages 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 purchasing or acquiring a new turtle, you should have your new pet 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.

They should run a fecal test 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 X-rays (radiographs) to check for other diseases. Typically, no vaccines are required for turtles.

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 or show you how to do it, 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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