Aggressive Iron Range moose suffered multiple parasites
A necropsy found hepatitis due to liver flukes, cysts, winter ticks and brainworm in an eyeball.
TOWER — The aggressive moose that challenged a driver and then battered a pickup truck and was euthanized by Minnesota Department of Natural Resources officers last week was suffering from multiple infestations of parasites.
Veterinarians at the University of Minnesota performed a necropsy on the cow moose and found it had hepatitis due to liver flukes, hydatid cysts in its lungs, a moderate winter tick infestation and brainworm was found in its eyeball.
“There are quite a few more tests pending. But we can make a fairly educated guess that parasite infestation, especially brainworm, was a contributing factor to its behavior,” Penny Backman, DNR wildlife manager in the Tower area, told the News Tribune.
Brainworm, called P. tenuis, is spread through white-tailed deer and snails, and, while harmless to deer, is usually fatal to moose. Moose in areas of higher deer densities are more likely to pick up the disease. It's considered one of the major factors in Minnesota's severe moose population decline over the past 20 years.
The moose, which showed up last week south of Eveleth near U.S. Highway 53, at first was reported as “stand-offish" by a driver on their way to work, said Shane Zavodnik, DNR conservation officer in the Virginia area. The driver eventually turned around and took a different route when the moose wouldn’t back down.
One day later, Zavodnik received another complaint in the same area from a logger who had returned to his personal truck that had been parked in the woods, only to find the vehicle had been heavily damaged by a moose. The truck's hood was dented and a side mirror ripped off with damage to the grill and headlight and moose hair stuck to various broken pieces and moose tracks all around.
The next day, logging operation owner Jeremy Stecker returned to the site where his employee's truck had been damaged and found the moose walking around, unafraid of his logging equipment. Stecker took several photos and a video of the moose.
Backman joined other wildlife staff, two other conservation officers and a sheriff’s deputy and eventually located the unusually aggressive moose and shot it, then sent the entire carcass to the university's veterinary laboratory for analysis.
The area where the moose was hanging out is south of what’s generally considered the state’s primary moose range in the Superior National Forest, where roughly 3,000 of the big animals still roam.
John Myers reports on the outdoors, environment and natural resources for the Duluth News Tribune. He can be reached at firstname.lastname@example.org .