Reptile-Related Diseases and Health Issues

Reptiles may carry bacteria (such as Salmonella) that can pose a health risk to people. Young children, elderly persons or immunocompromised individuals are particularly at risk.


Abscesses are pus-filled sores that occur in reptiles and can be a serious condition. They can be the result of bite wounds, environmental conditions, poor nutrition or illness.


Infection with parasites is common in reptiles and amphibians. Stressful life and concentration of animals in a small living space suppress the immune response and increase opportunities for bacteria, yeasts and funguses to develop, multiply and cause diseases. These can also be spread to other reptiles and humans, who can become ill from contact with them.

Fungus infections of the skin and gastrointestinal tract are common in reptiles. They can lead to septicemia and death. Affected reptiles may show listlessness, refuse food, have slow-healing internal sores and have a tan or yellow appearance to their skin and intestines. Fungal septicemia causes granulomas at the time of necropsy (an examination after a reptile’s death) in varying locations depending on species, such as the lungs, cloaca, or visceral organs.

To diagnose a fungus or parasite disease, your provider will do a fecal exam and take three or more samples of stool over the course of several days to send to a laboratory. Your provider will look for antibodies and antigens that indicate the presence of specific infections. Other diagnostic exams include a blood smear and an x-ray, magnetic resonance imaging (MRI) or computed tomography (CT) scan.

Bacterial Infections

Millions of households keep reptiles (such as turtles, lizards and snakes) or amphibians (like frogs and salamanders). These cold-blooded pets often carry germs that can make people sick, especially young children and elderly persons with weak immune systems. These germs, known as zoonotic infections, are caused by bacteria such as Salmonella.

Focal infections may develop due to traumatic injuries or bite wounds and are commonly seen in both captive and wild reptiles. These infections are characterized by subcutaneous abscesses that appear as nodules or swellings. Bacteria such as Peptostreptococcus, Aeromonas, Serratia, Escherichia coli and various anaerobic organisms are frequently isolated from these lesions.

Mouth rot is a bacterial infection that affects the tissue lining of the mouth and leads to ulceration, bleeding and septicemia. The bacteria responsible vary depending on species, but include Aeromonas, Pseudomonas and Salmonella. Infections resulting from improper diet or poor environmental conditions are also common. Symptoms of this disease include a loss of appetite, weight loss, difficulty eating, bloody or mucus-containing diarrhea and death.

Metabolic bone disease is a condition that can be fatal for some reptiles, particularly snakes and lizards. This disease is characterized by a lack of proper diet, temperature and humidity levels in their habitats, which prevent the reptiles from synthesizing and using calcium. In advanced cases of this disease, bone fractures are noted, especially in the long bones of legs and the skeleton of the jaw (fibrous osteodystrophy). The bacteria responsible for this illness are a group of non-tuberculous mycobacteria that form granulomas at different body sites depending on species.

Infections of the Cloaca

Infections of the cloaca are common in reptiles. They may be caused by bite wounds, other injuries, or poor environmental conditions. They are characterized by bacterial infection and inflammation with swellings that look like abscesses. The most frequent bacteria are Cellulomonas flavigena, Enterococcus faecalis, coagulase-negative Staphylococcus, and Escherichia coli. These bacteria represent the natural microflora of turtles’ cloacas.

Gout is seen in all orders of reptiles and consists of two forms, visceral (affecting the organs) and articular gout. It is characterized by high levels of uric acid in the blood. It can be due to a diet that is too protein-rich, or it can result from dehydration, kidney disease, or other causes. It causes the joints to swell and become painful, and it may cause death of the reptile.

A bacterium called Salmonella is commonly isolated from cloacae and oral fluids of reptiles. It may cause human illness, especially in children, the elderly, and persons with lowered immunity because of illness, pregnancy, chemotherapy, liver disease or other factors.

Skin maggots are common in tortoises and terrapins, and in some other species of reptiles. They are caused by a bot fly, which creates a wound in the skin and deposits its eggs there. The eggs hatch into larvae, which live in cyst-like structures under the skin until they mature and can be removed by your veterinarian.

Skin Infections

Reptiles are susceptible to a wide variety of skin infections. These are most often caused by opportunistic commensals infecting weakened hosts. It is important to determine the causative organism and to correct predisposing conditions, such as nutrition, environment, and disease state. Antibiotic treatment is ineffective unless environmental and husbandry factors are also corrected.

The fungus Candida can cause severe and fatal fungal infections in reptiles. These infections are characterized by granulomas, varying in location depending on species. Chelonians frequently have pulmonary involvement, while snakes and lizards may have skin or mouth lesions. These granulomas appear coarse, and the affected reptiles are debilitated due to a loss of red blood cells.

Focal infections, usually resulting from bite wounds or other injuries and made more likely by poor environmental conditions, are commonly seen in all orders of reptiles. These are often accompanied by abscesses, which appear as nodules or swellings under the skin. These are often filled with multiple bacteria, including anaerobic organisms such as Peptostreptococcus and the aerobic bacteria Aeromonas and Pseudomonas.

Infections affecting the respiratory tract are common in reptiles and can be caused by parasites of the respiratory system or the body, unfavorable environmental temperatures, poor ventilation, crowded housing, concurrent disease, malnutrition, and vitamin A deficiency. Respiratory infections are accompanied by open-mouth breathing, nasal or glottal discharge, labored breathing, and sometimes septicemia (widespread infection in the bloodstream). Nebulization therapy with antibiotics diluted in saline and acetylcysteine can be effective.