In various cultures throughout the world there is the widespread belief that animals, including companion dogs, are more likely to bite when under the influence of a full moon
http://www.dogexpert.com/full-moon-associated-with-dog-bites/
IDEAS that the moon inspires insanity in man and beast may be true say researchers who found that animals bite people more often when the moon is full. Doctors at Bradford Royal Infirmary recorded twice the number of animal bites on full moon days.
http://www.telegraph.co.uk/news/uknews/1379112/Beware-of-the-dog-during-a-full-moon.html
Seriously?