Veterinarians must not only be familiar with common reptile species and their management but also be able to extract clinically relevant husbandry information from the owner in a timely manner. The use of a history form can greatly facilitate this process and ensure that nothing is overlooked.
Species of Reptiles
Different species from different locations must not be mixed. Ideally, only a single species should be kept in any enclosure, and care must be exercised to avoid competition for resources such as food, basking areas, and retreats. In general, the solitary reptile pet is often the healthiest. Most nonbreeding pet snakes and aquatic turtles are best maintained as single pets, because trauma while feeding is common in groups. Some lizards, notably the chameleons (Chamaeleo spp), are so territorial that captive pets must be isolated for long-term survival.
Enclosure for Reptiles
The size of a reptile enclosure is important, and although many breeders and retailers may be able to intensively manage stock, pet owners should be advised on minimum enclosure sizes (see the table Recommended Minimum Space Requirements for Reptiles), the importance of providing the largest enclosure possible, and correct cage furniture.
The type of enclosure (arboreal, terrestrial, subterranean, or aquatic) should be appropriate for the species (see the table Important Husbandry Requirements for Selected Reptiles). In certain areas, the climate may permit keeping reptiles in outdoor enclosures, which is highly desirable, although theft, escape, predators, and wildlife carrying disease should be considered. Just 1–2 hours per week of unfiltered natural sunlight can have dramatic, positive effects on reptiles' health, so owners should be encouraged to provide natural sunlight whenever conditions permit. Depending on geographical location, large tropical tortoises and crocodilians kept outside will require some form of heated house during colder periods.
Glass aquaria are commonly used; however, the greater visualization perceived as an advantage to the owner may be stressful to the reptile. Glass is also a poor insulator, and greater heat loss may lead to dramatic temperature fluctuations. Even if the entire top of the enclosure is covered by mesh, ventilation may be severely hampered. Wood, plastic, and fiberglass enclosures are more versatile and preferable but can be expensive. Typically, substantial investment is required for an appropriate enclosure, which must be considered as part of the overall pet budget.
Several different types of substrate may be used in reptile enclosures. Newspaper, artificial turf, and organic particulates (eg, bark chips, recycled paper-pressed pellets) are suitable materials to line cages and vivaria, but they must be completely replaced regularly as they become soiled with feces and discarded food. Soil, sand, and natural leaf litter can also be used; however, oven baking is recommended to sterilize these materials before use. Gravel and pebbles are not recommended for terrestrial species, because they are difficult to clean and often ingested, leading to potential GI tract obstruction.
Other essential items include a water bowl (large enough for the reptile to bathe in) and various retreats (eg, cardboard boxes, cork bark, shredded paper). Clean, secure branches are required for arboreal species. Soap and water are generally all that is required to clean cages, but bleach can be used as long as rinsing is thorough. Some cleansers (eg, phenolic disinfectants) are toxic and should be avoided.
Recommended Minimum Space Requirements for Reptiles
Reptile Group | Minimum Space Requirement |
|---|---|
Tortoises and terrapins | 0.2 m2/0.1 m carapace length |
Purely aquatic chelonians | 0.25 m3/0.1 m carapace length |
Terrestrial lizards | 0.2 m2/0.1 m total length |
Arboreal lizards | 0.4 m3/0.1 m total length |
Boas and pythons | 0.6 m2/meter of snake |
Kingsnakes and rat snakes | 0.6 m2/meter of snake |
Whipsnakes and racers | 1.0 m2/meter of snake |
Arboreal snakes | 0.2 m3/meter of snake |
Important Husbandry Requirements for Selected Reptiles
Species | Habitat/Vivarium Type | POTZ, °C (°F)a | Humidity, % | Lightingb | Hibernation | Dietc |
|---|---|---|---|---|---|---|
Corn/rat snake | Terrestrial, scrubland | 25–30 (77–86) | 30–70d | NS | Yes | C |
Boa constrictor | Terrestrial, rainforest (semi-arboreal/aquatic) | 28–31 (82–88) | 70–95 | NS | No | C |
Ball python | Terrestrial, scrubland | 25–30 (77–86) | 50–80 | NS | No | C |
Leopard gecko | Terrestrial, arid scrub | 25–30 (77–86) | 20–30d | NS | No | I, c |
Green iguana | Arboreal, rainforest | 29–33 (84–91) | 60–85 | BS | No | H |
Bearded dragon | Terrestrial, desert | 25–32 (77–90) | 20–30d | BS | No | I, c, h |
Water dragon | Arboreal, rainforest | 24–30 (75–86) | 80–90 | BS | No | I, c, h |
Savannah monitor | Terrestrial, arid scrub | 25–32 (77–90) | 20–40d | BS | No | C, i |
Greek tortoise | Terrestrial, temperate to subtropical | 20–28 (68–82) | 30–50 | BS | Yes | H, c |
Box tortoise | Terrestrial, temperate to subtropical | 22–28 (72–82) | 50–80 | BS | Yes | H, I, c |
Leopard tortoise | Terrestrial, tropical | 25–30 (77–86) | 30–50 | BS | No | H, c |
Red-footed tortoise | Terrestrial, tropical | 25–30 (77–86) | 50–90 | BS | No | H, c |
Red-eared slider | Temperate to subtropical, gravel bottom or bare, water depth 30 cm (12 inches) minimum, land area ⅓ of tank | 22–27 (72–81) | Aquatic | BS | Possible | H, I, c |
Abbreviations: BS, broad-spectrum lighting; NS, no special lighting requirements; POTZ, preferred optimal temperature zone. | ||||||
a Temperature requirements shown are air temperature gradients. In general, basking temperatures should be 5°C warmer, whereas at night these temperatures should fall by 5°C. | ||||||
b BS, broad-spectrum lighting (UVB 290–300 nm) essential; NS, no special lighting requirements, although broad-spectrum lighting is still recommended because it is likely to have health benefits. | ||||||
c I or i = insectivorous, H or h = herbivorous, C or c = carnivorous; uppercase indicates major food preference; lowercase, minor food preference. | ||||||
d Humidity requirements are substantially greater during ecdysis. | ||||||
Heating for Reptiles
A variety of heat sources can be used in reptile enclosures, including incandescent bulbs, infrared ceramic bulbs, heating pads or mats, warming cables, tubular heaters, radiators, convector heaters, and natural sunlight radiation.
Heaters of an appropriate size should be thermostat controlled, screened from the animals, and positioned toward one end of the enclosure to provide a thermal gradient. “Hot rocks” frequently result in burns in larger animals and should be avoided. Light bulbs cannot be used to provide nocturnal heat, but some mercury-halide bulbs can provide both heat and broad-spectrum lighting.
Environmental Lighting for Reptiles
All reptiles, including nocturnal (active at night) and crepuscular (active at twilight) species, benefit from broad-spectrum lighting (see central bearded dragon image). However, UVB light (290–300 nm) is especially important for most diurnal lizards and chelonians for vitamin D3 synthesis and calcium regulation. The best source of lighting is unfiltered sunlight. However, many artificial fluorescent strip lights, compact fluorescents, mercury halide bulbs, and LEDs are available. The quality and intensity of these artificial lights should always be considered second-best to sunlight; however, they can be instrumental in preventing disease.
Courtesy of Dr. Stephen Divers.
Almost every light marketed for reptiles has the term “broad," "full," or "natural” on its packaging, creating confusion for veterinarians and pet owners alike. Appropriate lights must be labeled as providing UVB or, better still, be examined and tested using a spectrometer. Even suitable fluorescent lights must be placed relatively close to the reptile (< 30 cm [12 inches]), and replaced every 9–12 months. Mercury bulbs can provide greater penetration, up to 1 m or more, and can be replaced every 12 months. Most transparent plastic and glass barriers filter out UVB wavelengths. A photoperiod of 12 hours/day is suitable for general maintenance.
Humidity for Reptiles
Humidity that is too high or too low can create serious problems. The importance of humidity for reptiles has historically been underappreciated. Higher humidity levels have always been regarded as essential for many tropical species (eg, chameleons); however, high humidity microclimates are also often critical for many arid species (eg, tortoises, leopard geckos) to decrease shell pyramiding and dysecdysis.
Humidity is seldom directly controlled, although the advent of dedicated humidifiers and sprinkler systems makes this practical. Decreasing ventilation to maintain temperature and humidity is ill advised and frequently causes skin and respiratory disease. The addition of nontoxic plants to help maintain humidity can be effective for the smallest species; however, larger animals will frequently damage plants.
Quarantine and Recordkeeping for Reptiles
Although the incubation period of many reptile disorders is unknown, quarantine periods of 3–6 months for new reptiles are recommended. Owners should also be encouraged to keep detailed records of any changes in husbandry or nutrition, breeding activity, in-contact animals, disease outbreaks, health issues, recent additions, and previous problems and treatments. See Divers and Stahl's Mader's Reptile and Amphibian Medicine and Surgery (2019) for a more detailed discussion on common diseases affecting specific species.
Nutrition for Reptiles
Species identification is essential to critically appraise captive diets (see the tables Composition of Animal Foods That May Be Offered to Reptiles and Composition of Plant Foods That May Be Offered to Reptiles). Recommended diets for reptiles vary not only by species, but also by age, activity level, and environmental conditions.
A more detailed description of nutrition can be found in Divers and Stahl's Mader's Reptile and Amphibian Medicine and Surgery (2019).
Composition of Animal Foods That May Be Offered to Reptiles
Food Item | Dry Matter, % | Protein, % | Fat, % | Energy, Kcal/g | Calcium, % | Phosphorus, % | Ca:P Ratio |
|---|---|---|---|---|---|---|---|
Mealworms (Tenebrio) | 42.2 | 52.8 | 35 | 6.53 | 0.06 | 0.53 | 0.11 |
Superworms (Zophoba) | 40.6 | 17.4 | 17.9 | — | 0.01 | 0.02 | 0.43 |
Locusts | 31.2 | 61.7 | 19.4 | — | 0.1 | 0.75 | 0.13 |
Crickets | 38.2 | 55.3 | 30.2 | — | 0.23 | 0.74 | 0.31 |
Earthworms | 22 | 49.9 | 5.8 | — | 0.59 | 0.85 | 0.69 |
Waxworms | 38.3 | 15.5 | 22.2 | — | 0.03 | 0.22 | 0.13 |
Chicken muscle | 25.6 | 20.5 | 4.3 | 1.21 | 0.01 | 0.2 | 0.05 |
Egg, whole | 25.2 | 12.3 | 10.9 | 1.47 | 0.05 | 0.22 | 0.02 |
Mice, 1–2 d old | — | — | — | — | 1.6 | 1.8 | 0.88 |
Mice, adult | — | 19.86 | 8.81 | 2.07 | 0.84 | 0.61 | 1.37 |
Abbreviations: —, not applicable. | |||||||
Composition of Plant Foods That May Be Offered to Reptiles
Food Item | Dry Matter, % | Protein, % | Fat, % | Energy, Kcal/g | Calcium, % | Phosphorus, % | Ca:P Ratio |
|---|---|---|---|---|---|---|---|
Alfalfa | — | 15.5 | 37.1 | 3.94 | 1.29 | 0.21 | 6.14 |
Applea | — | 0.2 | 0.6 | 0.57 | 0 | 0 | 0.57 |
Bananaa | 29.3 | 1.1 | 0.3 | 0.79 | 0 | 0.02 | 0.25 |
Black currants | — | — | — | — | 0.06 | 0.04 | 1.4 |
Blackberry | — | — | — | — | 0.06 | 0.02 | 2.62 |
Broccoli | — | 3.6 | 0.3 | — | 0.1 | 0.06 | 1.49 |
Cabbage | — | 1.3 | 0.2 | — | 0.04 | 0.03 | 1.22 |
Carrots | 10.1 | 0.7 | — | 0.23 | 0.04 | 0.02 | 2.29 |
Clover hay | — | 11 | 1.9 | — | 1 | 0.2 | 5.0 |
Collard | — | — | — | — | 0.2 | 0.07 | 2.76 |
Cranberries | — | — | — | — | 0.01 | 0.01 | 1.36 |
Damsons | — | — | — | — | 0.02 | 0.01 | 1.5 |
Dandelions | — | — | — | — | 0.18 | 0.07 | 2.4 |
Endive | — | 1.7 | 0.1 | — | 0.08 | 0.03 | 2.67 |
Fennel | — | 2.8 | 0.4 | — | 0.1 | 0.05 | 1.96 |
Fig | — | — | — | — | 0.28 | 0.09 | 3.04 |
Grass (lawn) | 33 | 2.4 | 1.2 | 1.58 | 0.1 | 0.09 | 1.1 |
Iceberg lettuce | — | 1.2 | 2.5 | 0.14 | 0.03 | 0.02 | 1.34 |
Kale | — | — | — | — | 0.17 | 0.06 | 2.9 |
Lemon | — | — | — | — | 0.11 | 0.01 | 9.17 |
Lettucea | 4.1 | 1 | 0.4 | 0.12 | 0.02 | 0.02 | 0.85 |
Mustard cress | — | — | — | — | 0.06 | 0.06 | 1 |
Orange | 13.9 | 0.8 | — | 0.35 | 0.04 | 0.02 | 1.71 |
Parsley | — | — | — | — | 0.2 | 0.13 | 1.53 |
Radish | — | — | — | — | 0.04 | 0.02 | 1.63 |
Raspberry | — | — | — | — | 0.04 | 0.02 | 1.41 |
Red currants | — | — | — | — | 0.03 | 0.03 | 1.2 |
Spinach | — | 3 | 0.3 | — | 0.09 | 0.05 | 1.69 |
Tomatoa | 6.6 | 0.9 | trace | 0.14 | 0.01 | 0.02 | 0.62 |
Turnip | — | 1.1 | 0.9 | — | 0.05 | 0.01 | 2.89 |
Watercress | — | 2.2 | 0.3 | — | 0.22 | 0.05 | 4.23 |
White grapea | 20.7 | 0.6 | trace | 0.63 | 0.01 | 0.02 | 0.86 |
Abbreviations: —, not applicable. | |||||||
a The poor Ca:P ratio of these commonly used items may make them less suitable as a staple component of a reptile diet. | |||||||
Feeding rodents to rodent-eating carnivores, such as most snakes, presents few problems as long as the snake recognizes the rodent as food. Rodents that have been frozen for prolonged periods, especially if they are obese, may contain fewer nutrients and provide excess calories. Feeding live rodents is not advised (and is illegal in many countries) because of the dangers of prey-induced trauma to lethargic reptiles and the welfare implications for the live prey (see ball python image). Rodents should be offered to reptiles either freshly killed or thawed and warmed after a short period of freezing (< 4 months).
Courtesy of Dr Jessica Comolli.
Insectivorous reptiles can be well catered for with a variety of commercially available crickets, waxworms, tebo worms, hornworms, locusts, mealworms, cockroaches, earthworms, flies or fly larvae, and aquatic invertebrates. Feeding insects a nutritionally complete diet high in calcium and dusting the insects with a high-calcium reptile supplement (eg, calcium carbonate) immediately before offering them to a reptile is required to prevent nutritional deficiencies in reptiles (see common leopard gecko and box turtle images).
Courtesy of Dr. Stephen Divers.
Courtesy of Dr. Stephen Divers.
Providing herbivorous reptiles with a varied and nutritious diet can be difficult. Foods with a high calcium:phosphorus ratio should be selected with due regard given to the species-specific requirements for vegetables and fruits. Human nutrient databases can be useful resources for finding appropriate foods for specific species . Calcium or vitamin D3 deficiency (generally due to poor-quality lighting and low-calcium diets) leads to secondary nutritional hyperparathyroidism in insectivores and herbivores (see image of African spurred tortoise) and is common in reptiles kept as pets.
Courtesy of Dr. Stephen Divers.
A variety of commercially available foods are available for reptiles in moist, canned, and dry pellet forms. These may help provide a balanced diet, but they have not been critically evaluated and are seldom accepted as the sole diet without supplementation with vegetables and fruit.
Although some reptiles will drink from a water bowl, others will only imbibe water droplets on plants and décor. Poor water quality has been implicated as a cause of stomatitis in snakes. Lack of appropriate water delivery has been implicated as a predisposing cause of renal disease in green iguanas. Chameleons drink primarily from licking water droplets off of leaves and frequently become dehydrated when they are not allowed to do so. The advent of timer-controlled sprinkler systems or simple drip systems makes regular water provision possible for many of these more fastidious drinkers.
See also Nutrition in Reptiles.
For More Information
Divers SJ, Stahl SJ. Mader's Reptile and Amphibian Medicine and Surgery. 3rd ed. Elsevier; 2019.
