Fireflies might prove a fatal snack to exotic reptiles, according to a health alert released by the American Society for the Prevention of Cruelty to Animals' Animal Poison Control Center (APCC). Veterinarians should alert pet owners and advise them to take steps to prevent both the intentional or accidental ingestion of these common insects, the center reported.
Based on a handful of reports from reptile owners, symptoms of poisoning quickly follow a lizard's ingestion of fireflies. These symptoms include head shaking, oral gaping, unsuccessful attempts at regurgitation and a darkening in color. The symptoms usually appear within 30 minutes of ingestion, and death might follow within the hour. Death is thought to be a result of heart malfunction.
"A single firefly would have a very high probability of resulting in death," says Dr. Steve Hansen, board-certified veterinary toxicologist and director of the APCC.
The warning is being issued to amphibian and bird owners as well. In addition to the lizard cases, fatal poisonings in tree frogs have been documented. In another instance, a bird that ingested a firefly regurgitated it but did not die, says Hansen.
The health alert is based on about a half-dozen poisoning cases that have been reported to the APCC over the past few years. The most recent one, reported last summer, involved a bearded dragon that ingested a single firefly. The lizard was taken to a veterinarian and given a steroid injection. Unlike previous cases, Hansen said, the lizard recovered fully, though it is uncertain whether the animal regurgitated the fly or not.
The specific toxic agent responsible for the poisonings has not yet been identified. Also, despite the bearded dragon survival case, possible treatment for poisoned animals is uncertain because the animals die so quickly after ingesting the fireflies.
If ingestion of a firefly is witnessed, an owner should bring the animal to an exotics veterinarian as quickly as possible. Treatment of a poisoned lizard should be similar to that of a larger animal, such as a dog, Hansen said. The animal's stomach needs to be evacuated, and the symptoms need to be treated immediately. Hansen says a pet might have a chance of surviving if a talented exotics veterinarian is reached quickly enough.
However, Hansen says that reptile, amphibian and bird owners' first line of defense is prevention: make sure the pets do not have access to fireflies. Animals such as lizards are sometimes kept in open-top cages, Hansen said, which allow flying insects to enter the animal's environment.
Although the toxic agent acting in the animals is still unknown, veterinary toxicologists do have theories as to what might be causing the deaths of the pets. Fireflies of the genus Photinus contain lucibufagins, which are structurally similar to the well-documented toxins found in certain poisonous toads and plants. These have been shown to cause serious heart effects in dogs. Many of the documented poisoning cases involved bearded dragons. These lizards, which are commonly bred as pets in the United States, tend to be indiscriminant eaters, making it even more important that owners monitor their lizards' environments and diets.
Luechtefeld is a free-lance writer based in Southern California.