The Scoop on Turtles and Salmonella- Can Turtles Make You Sick?

Turtles are commonly perceived as disease carrying animals, having many nasty germs that they can spread to humans. The bacteria you have most likely been warned about in relation to turtles is Salmonella. This is the same group of bacteria that can be found in raw chicken and eggs. It can cause severe flu-like symptoms that may require hospital treatment.

So what’s the deal, can you catch Salmonella from a turtle? Well it depends if the turtle in question is a captive turtle, or a wild turtle. A turtle you encounter in the wild in Canada will likely not give you Salmonella, but your neighbor’s pet turtle Timmy could, although washing your hands after holding Timmy greatly reduces this risk.

Studies assessing rates of wild turtles in North America with Salmonella found very low infection rates of less than 5% (Brenner et al. 2002, Richards et al. 2005, Saelinger et al. 2006). In contrast, studies that have investigated prevalence of Salmonella in pet turtles in North America and Europe have found infection rates to vary from as low as 5% to as high as 80% (Cain et al. 2009, Heynol et al. 2015). That sounds concerning - up to 80% of pet turtles testing positive for Salmonella?!

It is important to keep in mind that proper precautions can prevent a pet turtle from spreading harmful bacteria to humans that handle them. Washing your hands after touching a captive turtle, or anything that has come in contact with its enclosure will keep you safe while interacting with our turtley cool pals. Regular cleaning of pet reptile enclosures is also important for preventing Salmonella bacteria from building up in the small volume of water in a turtle’s aquarium. For a more detailed list of best practices for staying healthy while handling and caring for captive turtles see https://www.cdc.gov/healthypets/publications/healthy-around-reptiles-and-amphibians.html

Turtles with Salmonella living in their intestines rarely show symptoms, and sometimes when tested for the bacteria, infected turtles will not test positive because they can release the bacteria at such low rates (Saelinger 2006). There is evidence that suggests turtles release more Salmonella in their feces when they are stressed (DuPonte et al. 1978, Mitchell 2005), and some researchers speculate that the distress turtles feel while in captivity causes them to release more Salmonella. This combined with the relatively small volumes of water in their enclosures explains why captive turtles exhibit higher rates of Salmonella (Richards et al. 2004). In the wild, it is also likely that turtles that are infected with Salmonella release such small amounts into their environment, that when they are swabbed for Salmonella it isn’t detected (Saelinger et al. 2006).

Negligible amounts of Salmonella in wild turtles is good news for all Turtle Guardians, and other conscientious citizens that stop to help turtles across the road during their active season (May - October). It means that if we help turtles across roads, or transport injured ones to turtle care facilities, we have a very small chance of getting sick from this. However, wild turtles may carry other diseases that don’t affect humans but that can make other turtles sick. And in any and all cases, it is still recommended that you wash your hands after handling a wild turtle- in fact this is recommended after handling any wild animal!!

Written by Meredith Karcz, Conservation Technician

References

Brenner, D., Lewbart, G., Stebbins, M. and Herman, D.W., 2002. Health survey of wild and captive bog turtles (Clemmys muhlenbergii) in North Carolina and Virginia. Journal of Zoo and Wildlife Medicine, 33(4), pp.311-316.
Cain, C.R., Tyre, D. and Ferraro, D., 2009. Incidence of Salmonella on reptiles in the pet trade. RURALS: Review of Undergraduate Research in Agricultural and Life Sciences, 4(1), p.1.
DuPonte, M.W., Nakamura, R.M. and Chang, E.M., 1978. Activation of latent Salmonella and Arizona organisms by dehydration of red-eared turtles, Pseudemys scripta-elegans. American journal of veterinary research, 39(3), pp.529-530.
Heynol, V., Heckers, K.O., Behncke, H., Heusinger, A. and Marschang, R.E., 2015. Detection of bacteria in oral swabs from healthy common musk turtles (Sternotherus odoratus) and West African mud turtles (Pelusios castaneus). Journal of Herpetological Medicine and Surgery, 25(1-2), pp.33-39.
Mitchell, M.A., Bauer, R., Nehlig, R. and Holley-Blackbum, M.C., 2005. Evaluating the Efficacy of Baquacil® Against Salmonella sp. in the Aquatic Habitat of the Red-Eared Slider, Trachemys scripta elegans. Journal of Herpetological Medicine and Surgery, 15(2), pp.9-14.
Richards, J.M., Brown, J.D., Kelly, T.R., Fountain, A.L. and Sleeman, J.M., 2004. Absence of detectable Salmonella cloacal shedding in free-living reptiles on admission to the wildlife center of Virginia. Journal of Zoo and Wildlife Medicine, 35(4), pp.562-563.
Saelinger, C.A., Lewbart, G.A., Christian, L.S. and Lemons, C.L., 2006. Prevalence of Salmonella spp in cloacal, fecal, and gastrointestinal mucosal samples from wild North American turtles. Journal of the American Veterinary Medical Association, 229(2), pp.266-268.