Bears are acting like friendly dogs due to a strange brain condition

A mysterious disease is making some black bears friendly and unafraid of humans, among other strange symptoms.

The researchers believe the disease, which appears to afflict young bears as young as about a year old, is a type of encephalitis, which means an inflammation of the brain, according to a statement from the California Department of Fisheries and Wildlife at the end last month. Since 2014, a handful of bears in Nevada and California have shown signs of the condition, and four California bears have been confirmed to have it last year.

“The first bear I personally rescued was diagnosed with encephalitis in March 2018,” Ann Bryant of Bear Education Aversion Response told Live Science. “She entered a school and entered a classroom where she sat among the children, behaving like a friendly dog.

Encephalitis has other serious effects on bears, including tremors, drooping heads and convulsions. Affected bears also tend to be severely underweight. A bear, observed in February picking up an apple and eating it among humans in a courtyard, weighed just 21 pounds, when it was supposed to weigh around 36 kg. She was also covered with ticks, walked strangely and ended up being sacrificed.

It is not yet clear exactly what is causing the inflammation of the brain. But while studying the phenomenon, scientists identified five previously unknown viruses in the affected bears.

These viruses are not believed to pose any risk to humans, Jamie Sherman, a veterinarian at the University of California, Davis’ One Health Institute, told Sacramento Bee.

Bears with encephalitis usually need to be euthanized. Their symptoms make them unprepared to survive in the jungle, and those placed in zoos or sanctuaries can become “a great burden” due to the medical care they will need for a lifetime, wildlife veterinarian Brandon Munk said in the CFDW statement.

Two bears exhibiting neurological problems in recent years, however, have been able to find new homes. One, now called Elinor, was taken to the Orange County Zoo. The other bear, which went viral after being caught on camera sniffing a snowboarder and is now named Benji, lives at the Ramona Wildlife Center of the San Diego Humane Society. Last month, Benji celebrated his third birthday there with a cake made of fruit and mashed potatoes.