Do Tortoises Carry Salmonella and Other Infectious Diseases?

No matter what kinds of pets you care for, hygiene is an important consideration. After all, animals can carry germs that may sicken people.  

This includes not only doing basic things like washing your hands after interacting with your pets, but it also means employing basic good-hygiene practices, such as keeping pets and their belongings away from (human) food-preparation areas.  

However, these types of practices are particularly important for turtle and tortoise keepers, as chelonians can carry a variety of infectious pathogens. And this includes a few that can lead to very serious illness in humans. 

I’ll explain everything you need to know about the germs your tortoise may carry and how to protect yourself from them below. 

What Is Salmonella?  

Salmonella is a genus of bacteria that is represented by two species and more than 2,500 documented serotypes (strains). Salmonella is quite common, and it is found throughout the environment. Soil and water are two common places the bacteria can be found, but it also inhabits the gastrointestinal tract of many animals. 

Some Salmonella are more-or-less harmless, but other strains can cause an illness known as salmonellosis. 

This typically manifests as mild to moderate gastrointestinal distress and causes symptoms including nausea, vomiting, and diarrhea. Other strains can cause very serious, systemic illness, which can even prove fatal in some cases. 

Nevertheless, all strains should be treated with caution and avoided to the extent possible. 

Salmonella is typically spread via the fecal-oral route, meaning that humans or animals who contract it typically do so by consuming food or water that has been contaminated with feces or the intestinal contents of an infected animal or person. Because birds – especially chickens – are often infected with Salmonella, undercooked chicken is one of the primary sources of human infections. 

Do Tortoises Carry Salmonella?

Yes, some tortoises carry Salmonella bacteria. 

Salmonella doesn’t always cause tortoises to display symptoms, and many will continue to look and behave normally, even if they’re infected with the bacteria. However, some tortoises – particularly vulnerable individuals, such as those who are already battling stress or other illnesses – may begin displaying signs of illness.

There are tests your veterinarian can carry out to determine whether your tortoise is infected with Salmonella, but they’re not always accurate. Some tortoises may be infected yet test negative for the bacteria. 

How Do Tortoises Contract Salmonella?

It isn’t entirely clear how tortoises contract Salmonella. In fact, the source of these infections likely differs from one animal to the next. However, a few of the most likely sources of infection include:

• A tortoise may crawl through infected feces or contaminated soil and inadvertently ingest the bacteria. 
• Some tortoises eat feces, which would lead to direct transmission. 
• A tortoise may drink water that’s been fouled with Salmonella-infected feces.  
• A tortoise may consume plants or fruit that’s been contaminated with Salmonella. 
• Some researchers believe that Salmonella may be transmitted from a tortoise’s mother during the egg-laying process. 

What Are the Symptoms of Salmonella in Tortoises?

As mentioned, Salmonella often fails to cause symptoms or illness in tortoises – many seem to harbor the bacteria without issue. However, in some cases, the bacteria can cause sickness in tortoises.

When that happens, a tortoise may exhibit one or more of the following symptoms:

• Lethargy: Tortoises who’re suffering from Salmonella infections may spend long periods of time in their hiding spaces or show a reluctance to move around very much. 
• Inappetence: When tortoises become ill with Salmonella, they may have a poor appetite. Some may continue to consume their favorite food items, but others will completely refuse food. 
• Diarrhea: Likely the most common symptom of Salmonella infection in symptomatic individuals, unhealthy looking poop, especially diarrhea may be the first sign that something is wrong. 
• Basking for prolonged periods of time: Tortoises who bask for longer times than usual may be trying to create a “behavioral fever,” which may help them to fight off illness. 
• Vomiting: Though not a very common symptom of Salmonella infection, some sick tortoises may vomit – especially those who’re suffering from serious infections. 

These symptoms certainly aren’t exclusive to Salmonella infections in tortoises; a variety of illnesses may cause these types of signs. But regardless of the reason your tortoise is displaying these types of symptoms, you’ll want to visit your vet promptly and get your pet the treatment he deserves. 

Salmonella, Turtles, and Humans: A Brief History

It’s important to understand the history of human Salmonella infections that were caused by chelonians, as it has had important ramifications for tortoise keepers. 

It started in 1965, when six children became seriously ill. 

The children were quickly diagnosed with salmonellosis, but that wasn’t particularly unusual; humans have suffered from the disease throughout recorded history. However, upon analyzing samples collected by the doctors treating the children, researchers found that — unlike most cases of salmonellosis, which were typically caused by the consumption of contaminated food — these children were infected by a type of Salmonella typically found in turtles. 

Twenty-two people were eventually found to have been infected during this initial outbreak. Most were children, but a few mothers also tested positive and displayed symptoms. 

Unfortunately, it would not be the last turtle-related Salmonella outbreak. In fact, these kinds of outbreaks became quite common over the following years as the popularity of pet turtles grew. During this time, hatchling turtles were often sold for very little money by pet stores, big box retailers, and transient vendors. 

By the early 1970s, there were an estimated 280,000 turtle-caused Salmonella infections diagnosed annually. This represented an estimated 14% of all human Salmonella cases each year. So, authorities decided that something had to be done to protect children and stop these outbreaks from occurring. 

Accordingly, in 1975, the U.S. Food and Drug Administration (FDA) enacted a regulation that banned the sale of turtles or tortoises with carapace lengths of less than 4 inches, except for bona fide scientific or educational purposes. 

The reasoning behind this regulation was that young children (who were at elevated risk of developing serious complications) were more likely to place a small turtle in their mouths. By preventing the sale of small turtles, it was hoped that children would be unable to place turtles in their mouths, thereby reducing the rate of infections. 

This law remains in effect, though it is commonly broken, and turtles and tortoises measuring less than 4 inches in length remain readily available. 

How Is Salmonella Transmitted from Tortoises to Humans?

Turtles and tortoises – even those who are asymptomatic carriers — commonly shed Salmonella bacteria in their feces. But these bacteria can end up contaminating the turtle’s body, as well as the enclosure, substrate, and any tools used in its care. 

If a human then touches any of these contaminated items with his or her hands, he or she may accidentally pass the bacteria into his or her mouth, resulting in illness.  It is also possible for household surfaces (especially countertops and sinks) to become contaminated, which could also lead to accidental ingestion. 

Who Is Most at Risk of Salmonella?

Most humans are susceptible to some strains of Salmonella, so everyone should take steps to avoid contact with the bacteria. However, people in a few key groups are at greater risk of falling seriously ill than others. These include:

• Young children: Young children are especially vulnerable to many Salmonella strains, thanks in part to their underdeveloped immune systems. In fact, children are likely the most common people to fall ill, thanks to turtle-related Salmonella infections. 
• The elderly: Older individuals are at heightened risk of contracting Salmonella and falling gravely ill. This is partially due to the fact that their immune systems do not function as well as they do for young adults and also because they often have comorbidities.
• People with compromised immune systems: The reason that many people don’t become gravely ill when infected with Salmonella is that their immune system is able to fight off the infection before it becomes serious. But people suffering from diseases or medical treatments that reduce immune function may become very ill if infected with Salmonella. 

How Can You Avoid Catching Salmonella from Your Tortoise?

While tortoises obviously can carry Salmonella, there are several things you can do to help reduce your risk of becoming sick. Some of the most important steps to follow include:

• Always wash your hands after touching your tortoise, his enclosure, or any of the items inside it. Use soap and warm water while scrubbing vigorously for at least 20 seconds, and then rinse your hands thoroughly. Standard soap will likely suffice, but some keepers prefer to use an antibacterial variety. 
• Avoid cleaning your pet’s food and water dishes in your kitchen or bathroom sink. Any time you clean your pet’s dishes, you will end up spreading small, potentially contaminated droplets around the area. So, either clean your pet’s dishes outside or in a dedicated sink, located in your garage (or a similar place). 
• Use a portable tub to soak your tortoises, rather than your sink or bathtub. Most tortoises will benefit from regular soaks, but you should avoid using your bathtub or sink for these purposes. Instead, purchase a suitably sized plastic tub and use this for soaking your tortoise. 
• Keep your tortoise’s enclosure very clean. To keep the overall number of Salmonella bacteria in your pet’s enclosure low, it is important to clean the area frequently. This means removing feces, shed skin, and uneaten food on a daily basis and replacing the substrate on a regular basis. You’ll also want to clean all of the items inside the habitat, as well as the enclosure walls. 
• Consider wearing latex or nitrile gloves when caring for your pet. While you’ll still want to wash your hands after tending to your pet, wearing disposable gloves can provide an additional level of protection. 
• Consult your vet immediately if your tortoise shows signs of illness. While tortoises can be asymptomatic carriers of Salmonella, they can also fall ill from the bacteria at times. In such cases, you’ll want to get your tortoise the care he requires promptly to help reduce the number of bacteria he sheds into the environment. 

Is Salmonella Treatable?

While there are some antibiotic-resistant strains of Salmonella, many kinds can be treated. However, things are often handled differently depending on whether you’re trying to treat a human or a tortoise. 

Treatment for Human Cases of Salmonella Infection

Many people don’t require treatment for minor cases of salmonellosis. In fact, countless cases are never diagnosed, as people suspect they’re simply suffering from “food poisoning” or the “stomach flu.” In these types of mild cases, the illness often resolves on its own in a matter of days.

However, more serious cases are often treated with a combination of antibiotics and supportive care, including rest and ample fluids. Very serious cases – especially those involving Salmonella typhi or related strains – may require hospitalization. 

Treatment for Salmonella Infections in Tortoises

Because tortoises often carry Salmonella asymptomatically, they don’t always require veterinary treatment. But tortoises who exhibit signs of illness – including gastrointestinal symptoms, lethargy, or inappetence – may require medical assistance. Most often, the care will be supportive in nature and primarily be limited to the administration of IV fluids. However, antibiotics may be prescribed in some cases.   

Nevertheless, even those tortoises who receive antibiotics may continue to shed the bacteria in their feces for weeks or months afterwards. 

How Can You Find a Tortoise That Doesn’t Have Salmonella?

It isn’t possible to ensure that the new tortoise you purchase will not have Salmonella. As mentioned, there are diagnostic tests veterinarians can perform, but they don’t always prove effective. Tortoises who are infected with Salmonella don’t shed the bacteria every time they defecate, so you may simply end up collecting a sample that does not contain the bacteria. 

With that said, you can likely reduce the chances of purchasing a Salmonella-infected tortoise by doing the following:

• Only purchase your tortoise from high-quality breeders or retailers. While even the best breeders and retailers can experience Salmonella outbreaks in their collections, low-quality, disreputable breeders and retailers experience these problems far more commonly. 
• Try to obtain your tortoise directly from the breeder, when possible. Simply put, the fewer places your tortoise lives the better. By purchasing your new pet directly from the breeder, you can eliminate the possibility that your tortoise will contract Salmonella from a pet store. 
• Never purchase a tortoise who’s exhibiting signs of illness. While some tortoises carry Salmonella asymptomatically, others will exhibit signs, including diarrhea, lethargy, and inappetence. It’s always wise to avoid purchasing sick pets, but this is especially true for owners seeking to avoid Salmonella. 

How Can You Prevent Your Tortoise from Contracting Salmonella?

In addition to doing the things discussed above to increase the chances of acquiring a tortoise who is Salmonella-free, there are also some things you can do to help prevent your pet from contracting the bacteria. 

Among other things, you’ll want to:

• Keep your tortoise as quarantined as possible. While you may keep your tortoise in a breeding group consisting of several animals, you’ll want to avoid unnecessarily allowing tortoises to cohabitate. Additionally, be sure to wash your hands (and any husbandry tools) after cleaning each enclosure.  
• Wash your hands thoroughly after visiting pet stores. Salmonella may be present in an array of places within a typical pet store. So, be sure to wash your hands after you leave. 
• Practice good hygiene when preparing your pet’s food. As with humans, tortoises can contract Salmonella from eating contaminated food. So, be sure to employ the same kinds of safe food handling practices when preparing your pet’s food as you would your own. 
• Keeping wild animals away from outdoor enclosures. Many wild animals – especially birds and reptiles — carry Salmonella, so be sure to exclude these types of animals from your tortoise’s outdoor enclosure. 

Do Tortoises Carry Other Infectious Diseases?

It is important to note that while salmonellosis is the most noteworthy zoonotic disease tortoises can spread, there are others. Specifically, tortoise keepers should be aware of two bacteria that can also be transmitted by tortoises:

• Campylobacter: A bacterial species that infects a range of animals, Campylobacter can also be transmitted by tortoises. Campylobacteriosis (the name of the disease caused by Campylobacter bacteria) typically causes diarrhea in humans. Treatments are available, though they’re most commonly supportive in nature. Antibiotics are used in some cases, but some strains of the bacteria are antibiotic-resistant.  
• E coli: E coli (which is short for Escherichia coli) is another very common group of bacteria, which are represented by more than 700 strains. Some of these strains live harmlessly in the gastrointestinal tracts of humans and other animals, but some can cause serious illness. Most E coli infections cause mild to moderate diarrhea, but some can be life threatening.   

Fortunately, you can reduce your risk of contracting either of these bacteria in the same way you’d avoid Salmonella: Practice good hygiene, including washing your hands after touching your tortoises. 

Citations

• Journal of the American Medical Association — Pet Turtles as a Cause of Human Salmonellosis
• Zoonoses Public Health — Multistate outbreak of turtle-associated salmonellosis highlights ongoing challenges with the illegal sale and distribution of small turtles
• Frontiers in Cell and Developmental Biology — Salmonella in reptiles: a review of occurrence, interactions, shedding and risk factors for human infections