It's not the werewolves of London running amok, but a new study suggests that dogs and cats may get into more medical mischief during certain phases of the lunar cycle. 

The study, authored by Raegan Wells, DVM, and her colleagues at Colorado State University's College of Veterinary Medicine and Biomedical Sciences, shows a possible link between an increase in emergency room visits for dogs and cats during days when the moon is at or near its fullest.

Wells said this is the first time the lunar cycle's relationship to emergency veterinary medicine has been studied. The study, titled "Canine and Feline emergency room visits and the lunar cycle: 11,940 cases (1992-2002)," appears in the July 15, 2007, issue of the Journal of the American Veterinary Medical Association.

The data, compiled from case histories of dogs and cats treated at the university's Veterinary Medical Center, indicates that the risk of emergencies on fuller moon days was 23 percent greater in cats and 28 percent greater in dogs when compared with other days. The types of emergencies ranged from cardiac arrest to epileptic seizures and trauma, and the increase was most pronounced during the moon's three fullest stages -- waxing gibbous, full and waning gibbous. "If you talk to any person, from kennel help, nurse, front-desk person to doctor, you frequently hear the comment on a busy night, 'Gee is it a full moon?'" said Wells. "There is the belief that things are busier on full-moon nights."

Just what is behind the correlation, however, isn't clear. "While the results of our retrospective study indicate that there is an increased likelihood of emergency room visits on the days surrounding a full moon, it is difficult to interpret the clinical significance of these findings," Wells writes.

What does all this mean for pet owners? "It serves as a good reminder to remain cognizant of your pet's environment and overall health status, and to avoid situations that would put them in harm's way," Wells said.

SOURCE American Veterinary Medical Association