A mysterious disease affects baribal bears in the US states of California and Nevada. Biologists are receiving reports of a hitherto unknown neurological disease in animals, in some cases causing death.
Typical symptoms are head tremors and head tilt, lethargy, and weight loss. In severe cases, death occurs, but even a surviving animal requires lifelong treatment and cannot be released.
The disease was first discovered 7 years ago in Nevada. Over the past year, at least 4 cases of the disease have been recorded in California alone. As a rule, young animals become its victims. Their examination shows the development of severe cerebral edema caused by various reasons, including viral infections.
In December last year, scientists identified 5 new viruses in sick bears, but they have not yet been able to find the main culprit of the disease. Researchers also do not yet know whether the disease in bears is dangerous for humans. And this is very important, since sick animals behave in a completely different way with people.
Affected bears stop being afraid of people and when they meet tourists in the forest, they fearlessly approach them. Two years ago, a video was filmed, as a bear cub without fear approached the snowboarder and trustingly clung to him. A little later, the animal was diagnosed with a disease. Brandon Munch, veterinarian for the California Department of Fisheries and Wildlife Conservation, says:
“Whenever a wild animal comes to us, the best possible outcome is a return to the wild. But this is simply not possible for such neurologically impaired bears. We do not currently know what causes encephalitis, so we do not know what health risks these bears may pose to other animals. “
Department officials warn the public to avoid contact with bears, even if they are friendly. Basically, warnings are made to protect the bears themselves, since such meetings are sometimes more dangerous for them than for people.