The Montana Department of Fish, Wildlife & Parks (FWP) reports three juvenile grizzly bears tested positive for highly pathogenic avian influenza (HPAI) virus this fall.
The three bears, one near Augusta, one near Dupuyer, and another near Kalispell, were observed to be in poor condition and exhibited disorientation and partial blindness, among other neurological issues. They were euthanized due to their sickness and poor condition.
These were the first documented cases of HPAI in grizzly bears. A fox and a skunk in Montana also tested positive for HPAI last year, and the virus has been found in raccoons, black bears and even a coyote in other states and countries.
“We suspect these mammals probably get the virus from consuming infected birds,” said FWP Wildlife Veterinarian Jennifer Ramsey.
Avian influenza (AI) virus is a naturally occurring virus in birds. AI viruses are classified into two groups, based on the severity of disease they cause in infected poultry. Low pathogenic AI viruses generally cause no clinical illness, or only minor symptoms in birds. HPAI viruses are extremely infectious and fatal to poultry and some species of wild birds.