Tortuga Gazette 30(8): 6-7, August 1994

Salmonella Prevention for Reptile Owners

by Douglas R. Mader, Carl Palazzola, William Ridgeway, Greg Perrault, and Thomas Greek

Question:

I've heard from several pet shop owners that it is illegal for them to sell baby water turtles because the babies have been known to carry harmful bacteria. Why is this, and am I at risk if I breed my two red-eared sliders (both are healthy)? I've owned the turtles for more than four years and would like to learn more about them.

Answer:

The bacteria you are referring to are Salmonella, the bacteria that cause salmonellosis.

In 1975, the Food and Drug Administration passed a law making it illegal to sell viable turtle eggs or live turtles with a shell length of less than four inches in the United States. [Editor's note: to read this law go to 4-inch regulations.] It was believed that animals larger than four inches did not pose the same threat as the bulk sold hatchlings, and as a result were still legal for trade.

Salmonellosis is perhaps the single most infamous zoonosis (disease that can be transmitted from animals to people) associated with reptiles. Over 200 types of Salmonella have been isolated from reptiles, including aquatic turtles, land tortoises, lizards, snakes and crocodilians. All of these types of Salmonella are considered dangerous to people.

The red-eared slider was the turtle that received the majority of the negative publicity. At the time that salmonellosis was a major disease concern, the slider was the most common type of turtle kept as a pet in the United States. In the early 1970's it was estimated that about 280,000 cases of human salmonellosis were contracted from pet turtles.

Salmonellosis is best diagnosed by a veterinarian. Microbiological cultures of the animal's feces, cloaca, or blood may identify the organism.

A positive test result is diagnostic for the disease, but a negative Salmonella culture can be misleading because the organism may not always be identified, even from a known positive animal. It is wise to recheck all negative animals two or three times, with a two week waiting period between each test to be certain that Salmonella is not present. Concerned owners are encouraged to set up a screening program with their veterinarian for salmonellosis and other important reptilian diseases. Since this is such a dangerous disease, all reptile and amphibian owners should use meticulous hygiene when handling or working with their animals. I give the following guidelines to all of my clients who have questions regarding salmonellosis, and especially in those cases where salmonellosis has been diagnosed based on a bacterial culture.

Guide-lines for Salmonella Prevention for Reptile Owners

1. Never eat or put anything in your mouth when working with your animals.

2. Never clean cages in the kitchen or anywhere you prepare food for human consumption.

3. Always wash your hands with a disinfectant soap after handling your animals. Iodine-based soaps are available from any pharmacy. Trade names such as Betadyne, Wescodyne, and Prepodyne are some of the more common brands available.

4. Have your veterinarian examine sick animals, or perform necropsies (animals autopsies) on animals that die suddenly, to check for Salmonella.

5. Make it a practice to keep cages clean. Proper husbandry and hygiene are fundamental to keeping healthy animals and minimizing disease transmission. This is true for all diseases, not just salmonellosis.

6. Young children and people under medical care from their physicians (such as antibiotic therapy, immunosuppressive drugs etc,.) should not handle reptiles and amphibians without checking with their physician first.

7. If you think you have been exposed to Salmonella bacteria or if you have any questions regarding the human form of salmonellosis, you are encouraged to contact your physician immediately.

Salmonellosis is not a disease to be taken lightly. It can cause death in animals and people. Because salmonellosis is a zoonotic disease and there are really no proven treatments for it in reptiles, our hospital usually suggests euthanasia of any animals with severe disease. Although this may seem harsh, it is often a better alternative than risking exposure of other animals in the household, or worse yet, of humans who come in to contact with the Salmonella-infected pet.

The real dilemma over whether to treat an animal or not arises when a clinically healthy pet tests positive during a routine health screen. Because many reptiles can act as carriers for Salmonella, and treating these animals indiscriminately with antibiotics could result in the evolution of drug-resistant organisms I usually recommend not treating any Salmonella-positive animals unless they develop overt signs of disease. I do recommend strict adherence to quarantine procedures and isolation of the positive animal.

Many antibiotics have been tried against Salmonella. What usually happens with treatment is that the animal will temporarily stop shedding the bacteria through its feces, and will harbor the organism internally only to begin shedding it again later. Even animals that have microbiologically tested negative on three separate occasions can potentially harbor and shed Salmonella organisms under certain circumstances.

To put this problem in perspective, herpetologists and reptile owners are at a greater risk of getting salmonellosis from incorrectly cooked chicken than from handling reptiles if good hygiene is practiced. A conscious effort at maintaining sanitary animal quarters, with proper attention to personal hygiene, will minimize the risk of infection with Salmonella bacteria.

For more information on Salmonella in reptiles check our Salmonella links on the CTTC Links page.