How do you prevent internal parasites in lizards?
Q. I was wondering if there is any other way of preventing internal parasites in lizards other than the typical disinfecting and cleaning of the enclosure? Thanks.
A. When discussing internal parasites in lizards, I assume that you are talking about your basic roundworms, Giardia and such. Some parasites, once infecting a lizard, may be almost impossible or truly impossible to eradicate safely. Cryptosporidium is one of those tenacious organisms that is probably impossible to eradicate.
To prevent infestation with internal parasites in lizards, we need to have an understanding of lifecycles. A parasite with a direct lifecycle is one that is directly infective to another animal (or itself), if the eggs or organisms are ingested. An indirect lifecycle requires an intermediate host (the prey item that is fed to the lizard, for example) that is usually ingested. This intermediate host usually is harboring some sort of parasitic larva that is released upon ingestion by the final host, in this case, the lizard in question, resulting in adult parasites in the intestinal tract or elsewhere.
So, key to preventing parasites is two-fold. First, cleaning up droppings as soon as they are passed is paramount in preventing a build-up of parasites that have a direct lifecycle. Next, any insects or other prey items that are fed to herps should be free of any larva involved with indirect lifecycles. Therein lies the problem. How can any of us be sure that insects or rodents being offered to pet herps are “clean” and free of any parasitic larvae? This becomes even more of an issue when feeding earthworms, snails, slugs or insects that are caught in our yards intended for being used as herp foods.
The best protection that we have is by purchasing insects and rodents from commercial sources that either screen for parasites that are involved with indirect lifecycles, treat their prey items to eradicate the larval form of parasites involved with indirect lifecycles or produce specific indirect lifecycle parasite-free insects or rodents. Ask your supplier of insects and rodents about their policy regarding intermediate hosts and their products. While no one can guarantee for certain that their insects and rodents are parasite-free, many make a concerted effort to eradicate or control them. It is possible to purchase specific pathogen-free rodents from specialized labs, and it is likely that, for a price, you can also purchase indirect lifecycle larvae-free insects, although this is not standard practice.
For parasite control, feed insects and rodents that are as clean as possible, pick up fecal material daily and either have susceptible herps on a prophylactic deworming program (as designed by your herp vet) or have fecal parasite examinations performed regularly (again as directed by your herp vet).
Margaret A. Wissman, DVM, DABVP has been an avian/exotic/herp animal veterinarian since 1981. She is a regular contributor to REPTILES magazine.
Need a Herp Vet?
If you are looking for a herp-knowledgeable veterinarian in your area, a good place to start is by checking the list of members on the Association of Reptilian and Amphibian Veterinarian (ARAV) web site at www.arav.com. Look for DVMs who appear to maintain actual veterinary offices that you could contact.