As a rule, reptiles and amphibians are remarkably free from disease. However, newly acquired specimen should, whatever their source. be isolated for a period of at least 2 weeks (preferably more). During this period, rigid precautions must be taken to avoid any risk of cross-infection since the newcomer may be suffering from an infectious disease. If any disease is suspected, veterinary advice should be sought as soon as possible.
Do-It-Yourself Treatment Is Discouraged
Only the most common and easily dealt-with problems are described, with emphasis on prevention and recognition rather than cure. Similarly, prophilactic treatment (preventive medication) is not recommended, except where this can be carried out easily and without risk of any side effects. Examples are the use of vitamin and mineral supplements on food, in drinking water or directly into the mouth, and the administering of worming substance, for instance piperazine citrate, for those species, such as tortoises, which are often found to be infested with roundworms (nematodes).
Western Pond Turtle (Clemmys marmorata
Photo credit: James Bettaso, U.S. Fish & Wildlife Service
The control of an outbreak of infectious disease may be difficult. However, certain elementary measures can be taken:
Isolate infected animals immediately, but resist the temptation to start shuffling other animals around in order to remove the most valuable from the vicinity. This may only help to spread the infection.
Never transfer water bowls, furniture, uneaten food from one contaminated cage to another.
Service the infected cage last - feeding, watering and clening should be carried out after all other jobs in the animal room are done.
Wash your hands and use a disinfectant "dip" for all tools and equipment after cleaning every cage in the room. Formalin, 70% alcohol or domestic bleach are satisfactory disinfectants for this purpose. Remember to rinse the equipment in clean water after using.
Disinfect every cage every time it is cleaned out. For reptiles, a solution of 3-5% sodium hypochlorite, or a quarternary ammonium compound, for example Cetrimide (diluted as indicated), or, in emergencies, a strong solution of ordinary washing soda (sodium carbonate), may be used. Phenols, and Coal-tar derivatives ) e.g. "Dettol" and "pine" disinfectants), are toxic to reptiles and should not be used. Amphibians are particularly vulnerable to toxic chemicals, although a weak solution of bleach (1-3%) will not be harmful, provided the vivaria are thoroughly rinsed afterwards.
Remove soiled bedding and dead animals from the room immediately by placing them straight into a polythene bag which can be tied at the top and disposed of. Do not leave such materials lying around in a refuse bin in the animal room.
A large number of viruses have been described in many different reptiles. Viruses that have been shown to be important pathogens in reptiles include ranaviruses and herpesviruses in chelonians, and paramyxoviruses in snakes. The viruses that have been most commonly detected in reptiles include herpesviruses, especially in chelonians, adenoviruses, especially in lizards and snakes, reoviruses, especially in lizards and snakes, paramyxoviruses, especially in snakes, picornaviruses in tortoises, and iridoviruses, with ranaviruses detected predominantly in chelonians and invertebrate iridoviruses detected in lizards.
Poxviruses have been repeatedly detected in crocodilians with skin lesions around the world. A poxvirus infection in a tegu lizard was associated with brown papules on various parts of the body. Ranaviruses have been increasingly shown to be important pathogens of turtles and tortoises in which viral infection has been associated with lethargy, anorexia, nasal discharge, conjunctivitis, severe subcutaneous cervical edema, ulcerative stomatitis, and “red-neck disease”. In the gecko, infection was associated with granulomatous lesions in the tail and liver. Ranavirus may be transmitted from amphibians to reptiles. Viral erythrocytic infections associated with irido-like viruses have been described in fish and amphibians as well as lizards, snakes, and turtles. In snakes, herpesviruses have been detected in venom glands of various species, in some cases associated with decreased venom production and liver cancer. In water turtles, herpesviruses cause lethargy, loss of appetitie, and tissue swelling as well as Gray patch disease in green sea turtles. Sea turtles are affected by Lung, eye, and trachea disease. Clinical signs associated with infection are gasping, harsh respiratory sounds, buoyancy abnormalities, inability to dive properly, and the presence of caseated material on the eyes, around the glottis and within the trachea. Some of the infected turtles die after several weeks. In sea turtles, fibropapillomatosis has been associated with herpesviruses infection.
Adenoviruses have been detected in wild Boa constrictors from Costa Rica and in wild-caught rattlesnakes and bearded dragons from the USA. A range of symptoms have been described in reptiles with AdV infection. The most common clinical sign in squamates is loss of appetite, which can also be associated with lethargy and wasting. Central nervous symptoms including head tilt and circling, as well as stomatitis and dermatitis. The intestine is also frequently affected.
Parvoviruses cause gastrointestinal disease in snakes and lizards. Infection with retroviruses cause is characterized by regurgitation followed by anorexia, and neurological symptoms including incoordination, disorientation, head tremors, lethargy and death. Pythons primarily show signs of CNS disease, while boas may show signs of CNS disease and/or regurgitation.2
The great majority of diseases affecting captive reptiles and amphibians are caused by incorrect husbandry. Temperature, humidity and spatial requirements must be met within certain limits or the animal(s) will become sick and eventually die. Animals suffering from poor management may show loss of appetite and subsequent emaciation, lethargy, poor color, dull skin, sunken eyes, surface wounds and sores, and in some cases extreme nervousness. With these, the cure consists of adjusting conditions until a more favorable environment is created.
The next most common problem is that of incorrect or inadequate nutrition. This is more likely to affect some species than others, especially where dietary requirements are unusual or poorly known. Assuming that ample food is available, nutritional disease consists primarily of vitamin and mineral deficiencies, the most important of which are the following.
Calcium : Phosphorus Imbalance
Calcium : Phosphorus Imbalance is most common in turtles and lizards. Thi smay be recognized by soft shells (in turtles) or bones, and resulting deformities. It is caused by offering food which is low in usable calcium (mainly meat, plant material and mealworms), and can be avoided by using a better diet, e.g. whole animals in place of meat, crickets in place of mealworms, etc, and by adding calcium to the food in the form of a mineral and vitamin supplement, ground cuttlefish shell, or as a chemical such as calcium lactate. In each case, the food is lightly dusted immediately before being offered.
Avitaminosis A is marked by swollen eyelids and loss of appetite (mainly in turtles). it is avoided by regularly placing a drop or two of cod-liver oil on a favored food items and by including liver, green vegetables and fish for diet. Badly affected animals may require injections of vitamin A by a veterinarian.
Avitaminisis B may take several forms, depending on which of the B-complex substances is lacking. Vitamin B1 (thiamine) deficiency affects the nervous system in snakes which are fed exclusively on fish giving rise to convulsions and, eventually, death. The culprit is an enzyme in the fish which digests the thiamine, thus depriving the snake of it. If the dead fish is warmed up for about 5 minutes, immediately before eating, the enzyme is destroyed and the problem eliminated. Vitamin B2 (riboflavin) deficiency causes paralysis of the hind leges in certain lizards (particularly iguanas, agamids and similar families). It can be best avoided by the use of a multi-vitamin supplement.
Lizards Deprived of Sunlight Develop Health Problems
Ultraviolet-A (UV-A) and ultraviolet-B (UV-B) types of light are amply
provided by natural, unfiltered sunlight. When reptiles, which synthesize
vitamin D3 in their skin, are denied access to UV-B, the synthesis of this important vitamin stops. The production of D3 is of paramount
importance, for in reptiles D3 is a calcium metabolizer. Lack of D3
results in an inability to metabolize calcium, even when ample calcium is
present in the diet. The end result of this is the onset of metabolic bone
disease. Thus, captive heliothermic (sun-basking) lizards need both exposure to
UV-A and UV-B light, as well as dietary D3 supplementation.
- Anoles, Basilisks, and Water Dragons. Richard D. Bartlett, Patricia P. Bartlett
- Viruses Infecting Reptiles. Rachel E. Marschang