Star-Tribune staff writer
As hunting seasons get under way, the Wyoming Game and Fish Department will be testing game carcasses in southwestern Wyoming to gain a better understanding of the wildlife populations in the area and specifically to look at diseases and parasites in animals.
Testing is performed every year, said Lucy Diggins-Wold with Game and Fish.
For the second year, the department will be putting more of a focus on moose, looking for parasites in the carotid arteries, Diggins-Wold said.
According to research from the department and the department’s wildlife diseases laboratory in Laramie, moose populations throughout the world have been declining, but especially southern populations, which includes Wyoming.
No single cause has been identified, but reduced habitat quality and increased parasite loads are considered possible contributing factors. The samples taken by department researchers will look at a particular parasite.
“We are working very hard to better understand, potentially stabilize or reverse this decline in moose populations,” Game and Fish biologist Mark Zornes said in a media release. “We are striving to sample as many hunter-killed moose heads as possible, and assistance from moose hunters is vital.”
The parasite Game and Fish is testing for lives in the carotid arteries of mule and black-tailed deer and is transmitted by horse flies. New hosts, such as moose, are susceptible to dry gangrene of the nose and ear tips, antler malformations, blindness, central nervous system damage and death.
Anectdotally, the prevalence of infection and the parasite’s geographic extent appears to have increased in Wyoming, Game and Fish research shows. In 1973-1974, none of the 69 Wyoming moose examined were infected, while three of five from Montana carried the worms in their carotid arteries.
In 2009, the Wyoming Game and Fish Department and Wyoming state veterinary lab conducted a major survey of hunter-harvested moose to establish baseline data. It was the most comprehensive and widespread effort to search for the parasite, E. schneideri, in moose in any state, the department said.
Nearly half — 75 of the 141 moose surveyed — had the parasite in their carotid arteries.
The prevalence of the parasite could be higher because the department only looked for the worm in the carotid arteries, while some moose could have been infected, but not long enough for it to move to the arteries.
The department examined moose heads and preserved the worms and tissue collections. Some of the tissue has already been examined, but many samples have not.
While moose continue to decline in Wyoming, it is unclear if the parasite is the sole cause or if there are multiple factors, Game and Fish officials said.
In response to the declines, Wyoming has issued dramatically fewer moose licenses in recent years.
Moose are just one type of game the department will be testing this hunting season.
Game and Fish’s primary concern is chronic wasting disease, Zornes said in the release.
Department researchers are also looking for bluetongue in deer or antelope and brucellosis in wildlife and livestock.
Brucellosis affects cattle, elk and bison and causes females to abort calves. Humans can contract the disease through contact with birthing fluids or from drinking unpasteurized milk. Game and Fish wants blood samples from cow elk killed in Hunt Areas 100, 102, 104, 106 and 107, the release said.
“It is very important we obtain as many of these blood samples from these cow elk as possible,” Zornes said in the release.
Testing is conducted in a variety of ways, Diggins-Wold said. Sometimes Game and Fish staff perform the testing at hunter check points where Game and Fish staff also look at licenses. Some hunters receive test tubes and directions for taking blood samples they mail into the agency. Others are asked to bring the head into a Game and Fish office for testing, she said.
Hunters in the areas in which Game and Fish is looking for brucellosis received letters asking for samples to be mailed. Blood samples cannot be frozen, but can last up to three days if kept cool or refrigerated.
Samples are tested at the University of Wyoming, Diggins-Wold said. It can take several weeks, or months, depending on the volume, to get individual test results back.