Veterinary research with snake venom sheds light in 2 areas

Gainesville, Fla.

-- A veterinary researcher and a biologist at the University of Florida believe they've found a safer, more effective method of collecting snake venom that has a variety of uses in human and animal medicine, and at the same time may have shed some new light on evolution.

Traditionally, venom has been collected from snakes by manually restraining them behind the head and having them bite a rubber membrane connected to a collection chamber. That requires handling a sometimes-aggressive snake, presenting a risk of snakebite to the handler and causing stress to the animal.

The Florida researchers used a portable nerve stimulator to extract venom from anesthetized cottonmouths, producing more consistent extraction results and greater amounts of venom, according to findings published in the August issue of Toxicon.

The study of venoms is important for many reasons, says Darryl Heard, BVMS, PhD, an associate professor in UF's College of Veterinary Medicine, department of small-animal clinical sciences, a zoological medicine veterinarian with expertise in anesthesia.

"The human and animal-health benefits include understanding the components of venom that cause injury and developing better antivenin. And the venom components have the potential to be used for diagnostic tests and the development of new medical compounds," Heard says. Snake venom also is used in some types of anesthesia.

Besides showing the extraction method is safer than the traditional "milking" method, Heard and Ryan McCleary, a PhD candidate in biology, discovered that the venom from the 49 snakes they studied, found on an isolated island near Cedar Key on the Gulf Coast, differs slightly from that of mainland snakes, possibly because of their unique diet of dead fish dropped by seabirds. The snakes on the island are noted for their large size, Heard says.

McCleary's research focuses on the evolutionary aspect -- the possibility that the venom from the isolated population may be changing in response to diet. "If these snakes already have an abundant source of dead prey, why do they need venom?" he asked, noting that early findings show some differences in venom components.