The concept of one medicine was invented by Calvin Schwabe in the 20th century. Its underlying assumption is that if humans are able to cure a disease in a particular species, the knowledge obtained from research studies should also be used to help other species. Therefore, human and veterinary medicine should use each other’s expertise and support mutual development.

In the 20th century, both fields of medicine followed separate paths and situations when specialists in one field drew knowledge form specialists in the second field were quite rare. It was only in 1976 that this approach was reconsidered by Schwabe, who took into account interactions and similarities between humans and animals when it comes to health, nutrition or habitats. Both veterinary and human medicine have common foundations i.e. anatomy, physiology, pathology and pathogenesis. In order to justify this claim we can consider an example of inflammatory bowel disease, affecting both humans and dogs. Dogs and humans suffering from IBD (Inflammatory Bowel Disease) show similar clinical signs and symptoms, have similar disease progression timeline and pathogenesis with the same cells, inflammatory genes and molecular pathways. Thanks to this finding, clinical studies conducted in dogs with inflammatory bowel disease play a particularly important role in the safety and efficacy studies of new medicines intended for human use in the future. The same is true for studies on congestive heart failure or cancer. Currently, most research projects are translational research studies in which pharmacokinetics and pharmacodynamics of drugs are first tested in animal models and only then in humans (you can read more on translational studies here: LINK). The fact that researchers have difficulties in proving the efficacy of new drugs in phase 2 studies, which prevents molecules from moving to a further stage of development, means that there is the need for an alternative approach at early stages of research and development. The desired approach may be reverse translational studies, which would enable researchers to combine the knowledge obtained from studying humans and animals suffering from similar diseases and use it to create better therapies for human and veterinary patients.

Nowadays, the world is constantly changing and this process is very dynamic and complex. Changes affect not only people but also the environment and the species living in it. Most of the problems we face are caused by the rapid growth of the human population and fast urbanization, intensification of livestock production and road traffic, as well as globalisation of trade. All these factors affect humans, companion animals and farm animals creating tight links between species. Having said that, wouldn’t it be logical to develop a unified approach in reference to human and animal health, which would also take the social and environmental context into account? At this point the clinical concept of “one drug” transforms itself into the holistic “one health” approach, which basically means that sustainable development depends on the health and well-being of humans, animals and the ecosystem in which they coexist. “One health” entails an interdisciplinary approach to the assessment, treatment and prevention of human and animal diseases. One of its most important components is comparative medicine, which involves the use of spontaneous animal models with naturally occurring diseases, in drug research and development. It is worth mentioning that pets and people are exposed to a number of the same environmental risk factors, which makes it much easier to gather control groups.

Reverse translational pharmacology is a very promising mode of selection of molecules which have the biggest potential in terms of efficacy and safety in human medicine. On the other hand, according to the “one drug” approach, information about the pharmacokinetics and pharmacodynamics of human study drugs may prove very beneficial for the development of veterinary medicine. The success of this approach will depend on the exchange of information and experience between experts in both fields, including translational research scientists. This already takes place in dynamic, interdisciplinary collaboration programs (e.g. Comparative Oncology Trials Consortium). An initiative of regulators supporting simultaneous development of drugs in veterinary medicine and human medicine would be an additional stimulus for researchers to cooperate effectively.

 The development of mankind has a significant impact on health and well-being of companion animals and farm animals. Therefore, in order to thank them for everything they do for us, we need to strive for quicker development of veterinary medicine and provide assistance whenever animals suffer and need us. As a dominant species over others, people often take a lot away from other species without giving anything in return. Developing new treatments for animals would be an ideal way to eventually offer something valuable to other living beings.