Koko, a gorilla, has used sign language to tell her handlers that she had toothache – and has had the tooth extracted.
Koko used the American Sign Language gesture for pain and pointed to her mouth, prompting treatment involving 12 specialists, including three dentists.
Her handlers said that Koko, a 300-plus-pound ape who has mastered more than 1,000 signs, began telling her handlers at the Gorilla Foundation in Woodside, California, she was in pain.
They constructed a pain chart, offering Koko a scale from one to 10. When Koko started pointing to nine or 10 too often, a dental appointment was made.
http://news.scotsman.com/latest.cfm?id=3317059