Zoonotic Diseases of Reptiles and Amphibians

Laurie Anne Walden, DVM

Photo by Vitya Lapatey

Reptiles and amphibians can carry germs that infect humans and other animals. Zoonotic diseases are diseases that spread from animals to humans. Most of the zoonotic diseases of reptiles and amphibians are caused by bacteria.
 
Reptiles and amphibians that carry harmful bacteria often have no symptoms and seem completely normal. If you have a reptile or amphibian pet, assume that it is harboring bacteria and use safe handling practices to keep everyone healthy.
 
Stress, poor nutrition, and an unclean environment increase the chance of a bacterial infection in a reptile or amphibian. Learn all you can about your pet’s husbandry and be sure you’re providing everything it needs: the right food, temperature, humidity, water quality, type and timing of lights, sanitation, and opportunities to engage in normal activities for its species (like climbing, burrowing, or hiding).
 
Salmonella
Salmonella infection is the most common disease that reptiles and amphibians spread to humans. People most often contract salmonellosis from contaminated food but can also be infected through the many animal species that carry Salmonella. With reptiles and amphibians, sources of infection are the animal itself, the animal’s food (including frozen or live rodents), water, habitat (terrarium or tank), and items inside the habitat.
 
Any reptile or amphibian can carry Salmonella. Outbreaks in humans in the last decade have been linked to turtles, bearded dragons, and crested geckos. The risk is especially high with very small turtles, which is why it’s illegal in the United States to sell turtles with shells less than 4 inches long.
 
Humans are infected by getting the bacteria in their mouths, so good hygiene—such as washing hands and keeping habitats clean—helps prevent infection. Symptoms of infection in people include diarrhea, vomiting, cramps, and fever. The risk of severe illness is highest for young children, elderly people, and people with impaired immune systems.
 
Animals that carry Salmonella are often not sick, so they have no symptoms. Reptiles and amphibians that are sick with salmonellosis might have decreased appetite, decreased energy, and diarrhea.
 
Mycobacterium
Mycobacterium bacteria are transmitted through contact with an infected animal or contaminated water. In people, infection causes skin sores and can spread throughout the body, especially in those with weakened immune systems. Reptiles and amphibians carrying Mycobacterium can have no symptoms at all or symptoms related to whichever part of the body the bacteria have infected: skin, lungs, joints, etc.
 
Aeromonas
Aeromonas bacteria live in water and spread through skin wounds or ingestion of contaminated water or other material. Fish, amphibians, and reptiles in aquatic environments can be infected. Symptoms of infection in people include wound infections, vomiting, and diarrhea. As with other types of infection, people with lowered immunity have the highest risk of severe disease. Infected animals can develop discolored limbs, bleeding disorders, and blood infections.
 
Other Bacteria and Parasites
Like all animals, reptiles and amphibians harbor a huge variety of bacteria, some of which could potentially infect humans. Reptiles and amphibians can also be infected with parasites like Giardia and Cryptosporidium that might pose a risk to people.
 
Safe Handling Practices

• Wash your hands after handling reptiles, amphibians, their food, their water, and items in their habitat.
• Don’t kiss your turtle. Or your snake or lizard or frog.
• Don’t bring reptiles, amphibians, or anything from their habitat into areas where human food is prepared.
• Don’t prepare food for your reptile or amphibian in the same place you prepare human food.
• Clean tanks, water bowls, habitat furnishings, and anything else associated with your pet outdoors if possible. If you clean these items indoors, do it somewhere other than the kitchen and disinfect the area afterward.
• Disinfect habitats, water bowls, and so forth with products that are safe for your pet’s species.
• The CDC recommends that children younger than 5 years, elderly people, and people with weakened immune systems not handle reptiles, amphibians, or items from their habitat. If your child has touched a reptile or amphibian, help them wash their hands afterward with soap and water.
• When you’re choosing your pet reptile or amphibian, buy one from a reputable breeder, pet store, or rescue group. Don’t catch a wild animal and keep it as a pet. Don’t buy a small turtle with a shell less than 4 inches long. Consider choosing a different type of pet if someone in your household is at higher risk of serious illness from zoonotic disease (young child, elderly person, or person with impaired immunity).

 
For More Information
See the Reptiles and Amphibians section of the CDC website: https://www.cdc.gov/healthypets/pets/reptiles.html
 
Photo by Vitya Lapatey on Unsplash

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