title: Canine and feline emergency room visits and the lunar cycle: 11,940 cases (1992-2002).
abstract: OBJECTIVE
  To determine the frequency of canine and feline emergency visits with respect to the lunar cycle.
  
  
  METHODS
  Retrospective case series.
  
  
  METHODS
  11,940 dogs and cats evaluated on an emergency basis during an 11-year period.
  
  
  METHODS
  Date of emergency visit, signalment, and chief complaint were retrieved from a medical records database. Emergency type was categorized as animal bite, cardiac arrest, epilepsy, ophthalmic, gastric dilatation-volvulus, trauma, multiple diseases, neoplasia, or toxicosis. The corresponding lunar phase was calculated and recorded as new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter, or waning crescent. The effect of lunar phase on the frequency of emergency visits was evaluated by calculating relative risk.
  
  
  RESULTS
  Of 11,940 cases, 9,407 were canine and 2,533 were feline. Relative risk calculations identified a significant increase in emergencies for dogs and cats on fuller moon days (waxing gibbous to waning gibbous), compared with all other days.
  
  
  CONCLUSIONS
  Results suggested that more emergency room visits occurred on fuller moon days for dogs and cats. It is unlikely that an attending clinician would notice the fractional increase in visits (0.59 and 0.13 more canine and feline visits, respectively) observed in this study at a facility with a low caseload. If the study is repeated at a facility with a robust emergency caseload, these results may lead to reorganization of staffing on fuller moon dates. A prospective study evaluating these findings under conditions of high caseload is necessary to determine the clinical relevance.
authors.affiliation: Veterinary Medical Center, Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: Raegan J
authors.initials: RJ
authors.lastname: Wells
authors.forename: Juliet R
authors.initials: JR
authors.lastname: Gionfriddo
authors.forename: Timothy B
authors.initials: TB
authors.lastname: Hackett
authors.forename: Steven V
authors.initials: SV
authors.lastname: Radecki
mesh_terms: D000818:Animals; D002415:Cats; D004285:Dogs; D004630:Emergencies / Q000453:epidemiology / Q000662:veterinary*; D005260:Female; D008297:Male; D016081:Moon; D010507:Periodicity; D012189:Retrospective Studies; D012306:Risk; D013997:Time Factors