Strange Illness Causes CA Bear Cubs To Act Friendly, 'Dog-Like'

CALIFORNIA — Last week, California wildlife officials traveled to a home in Pollock Pines, east of Sacramento, to investigate reports of peculiar behavior from a black bear cub. When they arrived, they watched a young female cub nonchalantly pick up an apple and chomp away at it in someone's backyard.

Not only was the young female bear exhibiting overly friendly and "dog-like" behaviors, but she was also underweight, walking oddly and was largely unresponsive, according to officials from the California Department of Fish and Wildlife.

Instances like these have been reported several times across the Golden State and experts are scrambling to figure out why.

A warden and a biologist from the state wildlife agency took the bear to an investigations laboratory in Rancho Cordova where she could be observed and evaluated by veterinarians.

The agency had received numerous calls about this same bear. She wasn't responding to people attempting to shoo her away or clap at her. In one report, she had even jumped into a housekeeper's open car trunk, beckoning residents to try and pet her.

"Contrary to CDFW guidance, residents began feeding the seemingly friendly little bear, admitting they had become attached to it," state wildlife officials wrote in a release. "They supplied it with water, apples and strawberries."

The problem is, several bear cubs in the Golden State have been seen out on their own at an age far too young and showing no fear of humans.

"Physically and mentally, the bear just didn’t seem quite right," officials from the agency wrote.

A week of observation and testing confirmed that the bear was experiencing neurologic and behavioral deficits, the state agency said. After the bear was euthanized, scientists confirmed she was suffering from encephalitis or inflammation of the brain.

She was the third bear discovered to have neurological disorders due to inflammation within the past year, the state said. A fourth bear showing similar behavior in Humbolt County was also recently euthanized.

"Any time a wild animal comes into our care, the best possible outcome is a release back to the wild," said CDFW wildlife veterinarian Brandon Munk in a statement. "That’s just not possible for these neurologically impaired bears. At this point, we don’t know what causes the encephalitis so we don’t know what, if any, health risks these bears might pose to other animals."

Munk said the second-best scenario would be a second chance at life at a zoo or wildlife sanctuary, but even that hasn't proven to be a successful solution.

"The few bears like this we have placed do not seem to fully recover, some requiring significant medical management for the life of the bear, which is a huge burden for these facilities that often operate on tight budgets," he said. "So neither release back to the wild nor placement in a facility is a good option for these bears."

The root cause of the disease remains a mystery, state officials said. But during their investigation, scientists have uncovered five novel viruses that were previously unknown.

"Complicating matters for wildlife officials, the neurologically dull bears appear friendly to the public," the state agency said. "Not fearing people, they may come into contact – and conflict – with humans more often."