From 11,940 cases (9,407 canine and 2,533 feline), a statistically significant difference in visits was calculated between full moon periods and all other periods. The researchers found the risk of emergency room visits to be 23 percent higher for cats and 28 percent higher for dogs on days surrounding full moons. The types of emergencies ranged from cardiac arrest to trauma.
The researchers pointed out that at a clinic with an average caseload it is unlikely that any clinician would be consciously aware of the very small but significant difference, but that these results may be useful for staffing timetables at clinics with a very high caseload.
This is only the latest in a range of historical studies on the effects of the lunar cycle on various aspects of human and animal life. One suggestion for the differences observed in this case is simply that more people (and their pets) are out during the full moon because the night is bright and good for walking.