There may be 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, according to researchers at Colorado State University’s College of Veterinary Medicine and Biomedical Sciences.
The data, which spanned 10 years of almost 12,000 case histories of dogs and cats treated at the university’s Veterinary Medical Center, indicates that the risk of emergencies on days with fuller moons 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.
This is the first time the lunar cycle’s relationship to emergency veterinary medicine has been studied, says Raegan Wells, DVM, an emergency and critical care medicine resident in the Department of Clinical Sciences at the University.
“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,” Dr. Wells said. “Many studies have investigated the effect of the moon on human nature, behavior and various medical problems, with evidence both supporting and refuting the effect.”
The data, however, did not indicate that there was an increase in aggressive behavior in dogs or cats during a full moon. For instance, there was not a measurable increase in injuries from dogs acting aggressively.
The researchers have several theories why there may be an increased number of visits during a full moon, but the data does not provide conclusive results.
One possible explanation is that full moons provide increased luminosity, which may correlate to an expected increase in nocturnal hunting rates among cats. If so, felines may be injured more often during these evenings. However, more feline cases related to trauma were not evident in the data.
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 Asssociation.