Dog that chewed his owner's toe off
Apparantly, the man had been neglecting his infection and would have surely succumbed to the infection and would have possibly died. Having to go to the hospital to have his chewed off toe tended to, revealed that he had diabetes. Incredible!
There have been reported cases where dogs have chewed on moles on owner's legs. Later to be revealed that the moles were cancerous! Those amazing critters.