The fatal condition known as inclusion body disease (IBD) was first diagnosed in snakes, particularly pythons and boa constrictors, in the 1980s.

Snakes diagnosed with IBD will often exhibit behavioral abnormalities, including an inability to flip over when turned on their backs and "stargazing," which involves staring off into space and weaving their heads back and forth as if drunk. They are also more likely to contract other diseases, such as bacterial infections in their mouths.

Infected snakes often refuse to eat, or regurgitate their food when they do.

"They begin to waste away," said study co-author Mark Stenglein, a biochemist at the University of California, San Francisco.

Scientists have long suspected a virus was behind IBD because the disease can be transmitted