Environmental news

Parasite kills mule deer around Roundup

Posted: May 3, 2011 11:10 AM by MT Fish, Wildlife & Parks

BILLINGS - (Press Release) A parasite spread through fecal matter apparently is to blame for dozens of dead or very weak mule deer in and around Roundup.

Montana Fish, Wildlife and Parks biologists have fielded numerous reports in recent weeks of mule deer with extreme diarrhea in and around Roundup. Many of those mule deer have died.

Jennifer Ramsey of Bozeman, FWP's wildlife veterinarian, said necropsies on several of the dead deer revealed an extreme number of parasitic Trichostrongylid worms and eggs - enough to seriously disable deer and kill young animals. Diarrhea caused by the parasites results in dehydration, emaciation and anemia, which can be fatal, particularly to young deer, she said.

The parasitic worms specifically attack ruminants - or animals with split hooves and multiple-chambered stomachs, Ramsey said. Those include deer, elk, antelope, moose, goats, sheep and cattle. The parasites occur naturally in such animals and become debilitating or fatal only when they reach extremely high numbers in an animal's stomach.

The worms spread between animals through fecal matter, Ramsey said. They reach fatal concentrations when infected animals eat grass or browse that in covered with infected fecal matter.

Artificial concentration of deer in and around Roundup is contributing to the problem as wildlife congregates around scarce food sources, including livestock feed grounds and places where people have left food for them, FWP wildlife biologist Jay Newell of Roundup said. Deer are more susceptible to parasites at this time of year because they are emerging from a long winter, he said.

While the parasite could spread to livestock, Ramsey said, most farmers and ranchers routinely treat their herds with a dewormer that stops the disease.

Trichostrongylosis infection in humans, dogs and cats is quite rare in the United States and easily treated with inexpensive medicine, Ramsey said. To catch the parasitic disease, she said, a person or pet would have to directly consume unwashed vegetables or water that was contaminated with deer feces. Normal, reasonable hygiene, such as washing hands, prevents spread of the parasite to humans, she said.