Animal Health Matters: Exotic animals can carry some not-so-exotic germ

Russ Daly
Special to the Farm Forum
Russ Daly

I am not much of an exotic pets person. While some of my veterinary school classmates were into parakeets, lizards and snakes, I never understood the attraction.

By all reports, however, an increasing number of people feel differently from me about these critters. Interest in exotic pets grows every year, with 13% of households in the US now keeping a “non-traditional” pet such as fish, hamsters, snakes, lizards and poultry.

Contributing to their popularity is the fact that most of these species are relatively easy to keep, especially in small apartments or houses. Most are gentle and pose little risk to their human caretakers.

In recent years, however, some of these species have been implicated as sources of disease-causing germs for their human handlers.

Recently, I wrote about the risk of Salmonella infections from baby chicks and backyard poultry. Over the past few months, reports have emerged of another exotic pet species serving as a source of the bacteria: bearded dragons.

Many hear the term “bearded dragon” and think of a character in a Lord of the Rings-type movie, but they are a reptile species becoming popular as pets. Bearded dragon aficionados will cite their docility and ease of care.

Daisy the bearded dragon at the reptile exhibit at the Earth Day Jamboree on Saturday, April 23, 2022 at Cambier Park in Naples, Fla.

I will admit: they are interesting to look at.

The Salmonella germ, however, represents a dark side of these pets.

The Centers for Disease Control and Prevention is actively investigating dozens of cases of human infections sourced from bearded dragons. Even here in South Dakota, a couple cases have been identified.

Salmonella infections are no fun for the people who get them. Diarrhea, vomiting and fever lasting several days are the norm, with some people needing hospitalization.

In fact, about a third of the bearded dragon-origin Salmonella cases have ended up in the hospital.

The South Dakota infections have proven interesting. The two Salmonella infections were identified in individuals from opposite ends of the state with no personal connections.

The Department of Health’s interviews with the patients revealed only one interesting commonality: both came from households that had bearded dragons as pets.

Fortunately, neither human infection was serious, and what followed was a neat example of public health cooperation.

The Department of Health determined that – despite the lack of connection – the germ was exactly the same in each person. The people were interested and cooperative, so with help from a couple students, I got samples from the bearded dragons (and their cages) on both sides of the state.

Lo and behold, Salmonella was present in both households’ animals and environments, with exactly the same fingerprint as the human cases.

How could two widely separated animals have exactly the same infection-causing Salmonella germ?

Commercial food is sometimes implicated as a point source in these cases, but not with these. Unfortunately, the other traceback trails fell cold, so determining a common point source has been elusive.

We learned from this exercise that, in the guts of the bearded dragons, Salmonella is part of the animals’ normal bacteria population: the animals never show signs of illness themselves.

Therefore, it’s not possible to rid them of the infection; they’re considered constant shedders of Salmonella.

In both cases, the pet owners were very interested in what they could do to reduce the risk of future infections.

Since Salmonella has to enter a person’s mouth to make them sick, handwashing after handling the animals is the one best thing that can be done to reduce the risk.

Indirect infections are also possible. Contact with the cages and rooms where the animal spent time is a potential source of infection, too. Limiting the bearded dragons to their cage rather than letting them out to roam around can limit this contamination.

If they need to be let out (for cage-cleaning, for example), they should be restricted to easily cleaned surfaces.

I suppose it could be said that almost any pet has some kind of downside. In the case of bearded dragons, Salmonella infections are certainly one of them.

Understanding the risks of these infections in people and how to prevent them will go a long way in making sure these human-dragon interactions are healthy ones.

Russ Daly, DVM, is the Extension Veterinarian at South Dakota State University.  He can be reached via e-mail at russell.daly@sdstate.edu or at 605-688-5171.