Here’s a comment from a well-meaning but ultimately misinformed reader. I’m commenting on it because these misconceptions are not uncommon.

"This blog post appears to be based on inadequate knowledge of iguanas. I am an iguana keeper and have been for several years.  Unlike many reptiles, iguanas do not carry salmonella on their skin and are not a high salmonella risk.  Furthermore, as long as the bath tub is disinfected afterward, there is generally no problem with iguanas bathing or even defecating in bath tubs shared with humans (although I do understand concerns of those with babies or immunocompromised people)."

Iguanas can and do carry Salmonella on their skin. It mainly resides in their intestinal tract but can easily contaminate their skin. For example, a 10-week study of 12 green iguanas reported that they all shed Salmonella at least once during the course of the study (Burnham et al, J Am Vet Med Assoc 1998). You have to assume that every iguana is carrying Salmonella.

People can and do get Salmonella from iguanas. There are numerous reports of salmonellosis from pet iguanas, including fatal infections. In a study of salmonellosis in people associated with exotic pets, iguanas were the most common source, accounting for over 50% of infections (Woodward et al, J Clin Microbiol 1997) Babies and immunocompromised people are at greatest risk, but infections occur in people outside of these high-risk groups as well.

Disinfection is far from foolproof. Yes, disinfection will kill Salmonella IF (and that’s a big if) it’s done properly. That includes properly disinfecting all tub surfaces, along with any other areas that were potentially contaminated (e.g. by splashes). This is far from guaranteed to happen in most cases, since people rarely understand what is required for proper disinfection and how to do it.

I’m not saying people should never have iguanas. Some people shouldn’t: households with children under five years of age, elderly individuals, pregnant women or immunocompromised individuals. In other households, the risk is lower, but it’s still there. An important part of managing the risk is knowing that the risk does exist. Pretending there is no risk doesn’t do anyone any good.