Intended for healthcare professionals


Do animals bite more during a full moon? Retrospective observational analysis

BMJ 2000; 321 doi: (Published 23 December 2000) Cite this as: BMJ 2000;321:1559

Dog bites and Lunar cycle

Editor - I read with interest the two articles on frequency of dog
bites related to seasonal changes, in particular the lunar cycle (1,2).

However, despite the humerous nature of this particular edition of the
Journal, I do feel that the authors of one of the papers (2) may have
thrown out the baby with the bathwater. They demonstrate that there is no
association between frequency of dogbites and phase of the moon, nor day
of the week, in Australia.

Nevertheless, there is something cyclical about the frequency of reported
dogbites, although admittedly it is not in phase with lunar changes. Even
if you draw a cutoff line below 10 bites per day, there are clearly 12
sharp peaks of bite frequency as high as 15 to 20 per day, lasting only a
day or so, occuring on a regular basis throughout the year. Do they occur
on the first day of the month, rather than the lunar cycle, as there are
12 months but 13 lunar phases in one year?

If I was told that the graph was actually a strip of poor quality ECG
recording, I would say that the patient has clear QRS complexes, is
regular enough to possibly be in sinus rhythm , but there is a lot of EMG
muscle artifact noise.

I feel that the data should be subjected to more detailed signal analysis
and other mathematical techniques which have been developed to recover
information from noise to tease out further the demonstrated regular
pattern of dogbite frequency. It my reveal some fascinating insight into
the habits of dogs and/or humans in Australia.

AS Laurence, Consultant Anaesthetist, Preston, UK.


1. Bhattacharjee C, Bradley P, Smith M, Scally AJ, Wilson BJ. Do
animals bite more during a full moon? Retrospective observational
analysis. Br Med J 2000; 321:1559-61.

2. Chapman S, Morrell S. Barking mad? Another lunar hypothesis bites
the dust. Br Med J 2000; 321: 1561-3.

Competing interests: No competing interests

18 January 2001
A S Laurence