How to prevent the vast majority of diseases in reptiles?
Few vertebrates are as intricately related to their natural environment as reptiles. Their physiological features, particularly those of being poikilotherm (their body temperature varies) and ectotherm (their body temperature varies according to the environmental temperature) make them vulnerable to the fluctuations of their surroundings. Each species evolves within a specific ecological niche in which there are ideal temperature and humidity gradients, sources of heat, water, light, shade, and food. The challenge in keeping and breeding reptiles in captivity, called herpetoculture, lies in the precise biological needs of each species. Furthermore, the biological needs of an individual may vary according to stage of growth, reproduction or time of year. It is precisely because of the failure to maintain optimal husbandry conditions for each reptile species that some illnesses have developed over the years in captive animals that are not found in their wild counterparts. By committing to providing the ideal environmental parameters for a captive reptile, it is possible to prevent the development of many such illnesses.
The following guidelines should be taken into consideration for the well-being of all captive reptiles. The specific parameters for a particular species can be discussed within the framework of a veterinary consultation.
- Provide a terrarium that is size-appropriate. Too little or too much space can induce chronic stress that can have grave long-term consequences.
- The 'preferred optimal temperature range' (POTR) is a key notion for the health of a reptile. It is crucial to provide a temperature gradient with a hot spot and cold spot, which are monitored with a digital thermometer. The accuracy of a thermometer can be verified by placing it in a room of known temperature. Ideally, heat sources should be arranged to create a horizontal as well as a vertical gradient. The POTR is specific to each species.
- Several products exist to provide supplemental heat. Heating lamps are ideal. The heat emitted by a heating lamp can be controlled by the selection of the power of the bulb (watts) or by varying the distance between the lamp and the terrarium. Infrared and ceramic lamps provide heat without light and so can be used to provide supplemental heat at night.
- Heating rocks or pads are not recommended because the heat they provide is less well controlled than in heating lamps, and can cause thermal burns. Moreover, when using a ground heat source, it is difficult to create the vertical gradient (heat from above, cooler below) generally recommended for reptiles. Heating pads may be necessary though to provide a high ambient temperature for some species that require it.
- Quality of light is an important factor for the maintenance of a healthy metabolism. Different lamps provide different wavelengths of light (infrared, visible, UVA, UVB) and should be chosen based on the specific needs of the species. Full spectrum light bulbs need to be replaced every 6 months to ensure that they continue to provide UV wavelengths (which are not visible to the human eye). They should be placed no higher than 24 inches from the ground and should not be obstructed by glass or plastic.
- A day/night cycle can be controlled by using a timer and should be adjusted according to the specific needs of the species.
- Provide hides in different temperature zones. A hide can be constructed of plastic, ceramic, wood, resin, or well-anchored stones. A wooden hide can be soaked in water to offer a humid area. For arboreal species, natural or artificial foliage can provide a place to hide in different temperature zones. Hides provide shelter for shy animals but are also sources of environmental enrichment for more adventurous individuals. A paper-based non-dusty substrate can be provided for species that enjoy burrowing.
- The water needs of reptiles vary greatly. From fully aquatic species to desert species, it is important to provide a clean, easily accessible source of water for drinking or bathing. Water temperature needs to be controlled for aquatic and semi-aquatic species. For terrestrial reptiles, water sources and humidity need to be adapted to the environmental requirements and the behaviours of the animal. Many captive reptiles suffer from chronic dehydration, even among desert species. It is why we recommend bathing your terrestrial reptile once a week in warm water (95-103˚F), under supervision.
- Remove stool, urine, and uneaten food as well as soiled substrate every day. Clean the entire terrarium once a week. Appropriate substrate choices are paper-based litter for burrowing animals, reptile carpets or towels for non-burrowing species.
- Monitoring a reptile's weight once a month and even creating a weight chart can help detect illness (a weight loss of 10% or more is suggestive of a problem). Healthy reptiles grow throughout their life although the growth rate slows once they reach reproductive age.
An annual exam is recommended for all animals. During the consultation, the growth and health status of the animal is evaluated, as well as the husbandry parameters.
Édouard Maccolini, DVM, IPSAV (Zoological Medicine)