Evidence-informed (also referred to as evidence-based) veterinary medicine is the concept of applying scientific evidence to the treatment of animals in our care. The concept was borrowed from human medicine in the early 2000s and has since generated considerable discussion, as well as inclusion in the curriculum of many veterinary schools.
The idea of using scientific evidence to support treatment decisions augments the clinical experience and judgment veterinarians bring to each patient. In other words, experience is important and research can be a valuable addition to this foundational knowledge.
There are many ways scientific information is generated and shared, with some offering stronger forms of evidence compared to others. Opinions such as the ones I share in this column are rated as quite low on the evidence scale since my writing in this publication is not assessed by my scientist peers and draws heavily on my clinical experiences.
On the other hand, scientific papers that systematically review and assess all the scientific literature on a topic to draw conclusions are given the highest ranking in terms of strength of evidence. Somewhere in the middle are case studies, descriptive studies and then experiments that have all undergone peer-review by other scientists. The weight of scientific evidence grows when studies are repeated and the results are similar.
There is inherit uncertainty both in the practice of veterinary medicine and science. Each animal, disease and circumstance will vary slightly from previous ones. A veterinarian must assess the individual case and draw on all the information available to reach a diagnosis and treatment plan.
Science also has uncertainty as a cornerstone of its philosophy. In order to adhere to the scientific method, hypotheses and theories must be testable and open to being disproved. This is why it is hard to get a straight answer out of most researchers — there is always a chance what they say could be proven wrong and the nature of science communication lends itself more to hedging then certainty.
Science also requires an ample dose of skepticism. It often surprises me how often opinions and dogma weave their way into scientific studies.
A few years ago, I was researching diseases of wild urban rats. Scientific paper after paper mentioned the risk of rats carrying a bacterium called Francisella tularensis. These bacteria cause tularemia in people, a serious infection disease.
As I traced the references back to their original sources, I was unable to find a single case of this infection in wild rats reported in the scientific literature.
My conclusion was that well-meaning authors of scientific papers had read about muskrats as carriers (a well-established phenomenon in Canada and elsewhere where muskrats have been introduced) and somewhere along the way, muskrats was short-handed to simply rats. Then it was repeated over and over again in subsequent papers. When I asked the question, “where is the evidence?” it turns out, there was none.
To really develop studies that a clinical veterinarian can use to connect the laboratory to the farm, researchers need to ask the right scientific questions and work on problems relevant to industry and their animal health concerns. Science isn’t perfect but it is the best we have.
To paraphrase Sir Winston Churchill, scientific research is the worst knowledge-generation tool, except for all those other forms that have been tried from time to time. The alternative to facts, science and knowledge is a world of falsehoods, myths, antidotes and ignorance.
In this post-truth era, it is important to remember that support for science and education is support for knowledge and truth, which benefits our animals and society as a whole.