From 229 veterinary practices, the researchers counted 1,722 canine chocolate eaters over a six-year period. Reports of chocolate exposure were four times more likely on Christmas compared to every other holiday. Easter turned out to be twice as likely to have chocolate reports. But Halloween and Valentine’s Day, known for hefty chocolate indulgences, were solidly average. What gives? P-J Noble, a veterinarian at the University of Liverpool and lead author of the study, says that Valentine’s Day may pose less of a threat because chocolate is mostly shared by adults, as opposed to being handed out to guests and children all over a pet owner's home.