• 1

    Bhattacharjee C, Bradley P & Smith M, et al. Do animals bite more during a full moon? Retrospective observational analysis. BMJ 2000;321:15591561.

    • Search Google Scholar
    • Export Citation
  • 2

    Zargar M, Khaji A & Kaviani A, et al. The full moon and admission to emergency rooms. Indian J Med Sci 2004;58:191195.

  • 3

    Alves DW, Allegra JR & Cochrane DG, et al. Effect of lunar cycle on temporal variation in cardiopulmonary arrest in seven emergency departments during 11 years. Eur J Emerg Med 2003;10:225228.

    • Search Google Scholar
    • Export Citation
  • 4

    Chapman S, Morrel S. Barking mad? Another lunatic hypothesis bites the dust. BMJ 2000;321:15611562.

  • 5

    Butler S, Songra A & Hardee P, et al. The moon and its relationship to oral and maxillofacial emergencies. Br J Oral Maxillofac Surg 2003;41:170172.

    • Search Google Scholar
    • Export Citation
  • 6

    Benbadis SR, Chang S & Hunter J, et al. The influence of the full moon on seizure frequency: myth or reality? Epilepsy Behav 2004;5:596597.

  • 7

    Wolbank S, Prause G & Smolle-Juettner F, et al. The influence of lunar phenomena on the incidence of emergency cases. Resuscitation 2003;58:97102.

    • Search Google Scholar
    • Export Citation
  • 8

    Nunez S, PerezMendez L, and Aguirre-Jaime A. Moon cycles and violent behaviors: myth or fact? Eur J Emerg Med 2002;9:127130.

  • 9

    Sinnott RW. The great escape and the moon. Sky Telescope 1994;Apr:8688.

Canine and feline emergency room visits and the lunar cycle: 11,940 cases (1992–2002)

Raegan J. Wells DVM1, Juliet R. Gionfriddo DVM, MS, DACVO2, Timothy B. Hackett DVM, MS, DACVECC3, and Steven V. Radecki PhD4
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  • 1 Veterinary Medical Center, Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523
  • | 2 Veterinary Medical Center, Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523
  • | 3 Veterinary Medical Center, Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523
  • | 4 Biostatistician, 150 N County Rd 3, Fort Collins, CO 80524

Abstract

Objective—To determine the frequency of canine and feline emergency visits with respect to the lunar cycle.

Design—Retrospective case series.

Animals—11,940 dogs and cats evaluated on an emergency basis during an 11-year period.

Procedures—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 and Clinical Relevance—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.

Abstract

Objective—To determine the frequency of canine and feline emergency visits with respect to the lunar cycle.

Design—Retrospective case series.

Animals—11,940 dogs and cats evaluated on an emergency basis during an 11-year period.

Procedures—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 and Clinical Relevance—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.

Contributor Notes

The authors thank Kim Marren for technical assistance.

Address correspondence to Dr. Wells.