Commentary: Epidemiology for Better Horse Health

This issue (April 2012) of the Equine Disease Quarterly features an article by Dr. Noah Cohen (VMD, MPH, PhD, Dipl. ACVIM) addressing the subject of epidemiology. Dr. Cohen skillfully and artfully broached this topic in detail in the Milne Lecture in November, 2011, at the 57th annual convention of the American Association of Equine Practitioners. As he pointed out, epidemiology is often viewed, much like statistics, in an unfavorable light by students, practitioners, and even academicians. Epidemiology--the study of health and disease events in populations--is often thought of as akin to public health and involving screening, risk factor assessment, and statistical analysis of data with the goal of preventive medicine. In many minds, epidemiology is far removed from day-to-day equine-related practice and activities.

As Dr. Cohen points out in his article in this issue, practitioners are constantly involved in examining and evaluating populations of patients and making judgments on the appropriate course of action based on their own experiences or those of others, all of which culminates in a population-based approach (epidemiology).

In fact, when the articles in this issue are evaluated, one finds that each of them is deeply rooted in epidemiology. The parasitology report has its basis in population studies on farms and of groups (ages and uses) of horses. The ever-evolving saga of parasite resistance is best studied and attacked on an epidemiological basis. Also, the current approach to parasite control, which is gaining more attention, is totally based on epidemiology. Parasite control is a population approach of testing and then deworming based on worm burdens instead of simply deworming horses based on the calendar. It is perhaps a more effective means of controlling parasites and mitigating the development of parasite resistance.

Likewise, the article in this issue on conditions affecting the geriatric horse is a population-derived study. A population shift has occurred to include more old horses. With this shift, conditions and diseases affecting geriatric horses have taken on more importance, and it is a priority to develop strategies to approach their health issues. This focus is based on findings in and experiences with this population, so now when we deal with an individual geriatric horse, we employ epidemiological-derived knowledge.

Finally, the Fourth Quarter 2011 Report from the International Collating Center and other sources is a pure epidemiological account of disease outbreaks and trends. Its value for the awareness and control of equine diseases cannot be overstated.

So, while we may not always like to think about epidemiology, Dr. Cohen is correct. Epidemiology does not always involve experimental models mired in statistics. As every article in this issue confirms, epidemiology often involves studies of our very own patients and populations of those patients in which we constantly utilize population-based knowledge. So the better we understand the principles of epidemiology, the better for the horse.

CONTACT: Neil Williams, DVM, PhD, Dipl. ACVP, 859/257-8283,, Veterinary Diagnostic Laboratory, University of Kentucky, Lexington, Ky.

This is an excerpt from Equine Disease Quarterly, funded by underwriters at Lloyd's, London, brokers, and their Kentucky agents.

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Equine Disease Quarterly

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