In this retrospective study, 11,940 dog and cat emergency room visits to the Colorado State University Veterinary Medical College were evaluated to determine the frequency of visits with respect to phases of the lunar cycle. The cases were evaluated over an 11-year period. Types of visits were separated into 9 broad categories: animal bites, cardiac arrest, seizures, ophthalmic disorders, gastric dilatation volvulus, trauma, toxicosis, neoplasia, and multiple diseases. The corresponding phase of the moon (new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, or waning crescent) was calculated for each date of the visit. The canine cases were calculated separately from the feline cases. Compared with other days in the lunar cycle, there were no significant differences in the number of emergencies for both dogs and cats on full-moon days alone; however, when all "fuller" moon days were grouped together (ie, waxing gibbous, full moon, and waning gibbous phases), there were significantly more visits for both dogs and cats compared with other days. In conclusion, it is unlikely the clinician would notice increased emergencies at a hospital with a small emergency caseload, but these results could have an impact for staffing concerns at veterinary facilities with large emergency caseloads.

COMMENTARY: The significance of the term "full moon" comes to mind as one reads this interesting article that discusses an important aspect of veterinary emergency medicine. The article also points out some of the shortfalls of the study and ways to support its significant findings. Most important, it cites a way to improve staffing to avoid overworking current employees and provide the best service to patients.

Canine and feline emergency room visits and the lunar cycle: 11,940 cases (1992-2002). Wells RJ, Gionfriddo JR, Hackett TB, Radecki SV. JAVMA 231:251-253, 2007.