Simon R. Platt, BVM&S, MRCVS, DACVIM (Neurology) & DECVN
University of Georgia
“When the number of factors coming into play in a phenomenological complex is too large, scientific method in most cases fails. One need only think of the weather, in which case the prediction even for a few days ahead is impossible.”
— Albert Einstein
Is predicting the success of therapy for a specific veterinary disease impossible? Will we soon be able to know which patients we can actually “cure” based on their genes? Laying the foundation for the answers to these questions has begun now that we have the ability to genetically test our patients.
Most medical treatments are designed for the “average patient,” a type of “one-size-fits-all” approach that is not uniformly successful. Precision medicine, sometimes known as personalized medicine, is a novel approach to disease prevention and treatment that takes into account differences in genetics, environment, and lifestyle. Advances in precision medicine in humans have already led to major new discoveries and several new Food and Drug Administration–approved therapies designed to the specific characteristics of individuals. As an example, human patients with a variety of cancers routinely undergo genetic testing, enabling treatment selection that improves their chance of survival and reduces the potential for adverse effects.
Although genomic testing is still a relatively new development in drug treatment, this field is expanding. Currently, more than 100 drugs have label information regarding pharmacogenomic biomarkers (genetic information that can be used to direct the use of a drug). When the genomes of people taking the same drug are compared, people who share a certain genetic variation also seem to share a common treatment characteristic, such as the need for a higher dose to achieve a therapeutic effect or an optimal duration of treatment. This kind of treatment information is currently used to improve the selection and dosage of drugs to treat a wide range of conditions in people, including cardiovascular disease, lung disease, HIV infection, cancer, arthritis, high cholesterol, and depression.
Animal DNA testing is now offered by a plethora of companies, confirming breed types, parentage, and predisposition to diseases. We have been aware for many years that we can use such genetic tests to assist in herd health and production performance as well as to confirm disease presence in specific breeds. However, the genetic evaluation of our patients has the potential to revolutionize our practice and improve our treatment outcomes. Molecular characterization of veterinary diseases with similarly characterized human disorders for which precision treatments have been or are being developed will allow us to utilize what is already known. Clinical trials involving human and animal cancer patients are increasingly providing information about shared genetic abnormalities that represent important drug targets. In time, precision veterinary medicine will likely have an impact on treatment not only of cancer but also of diseases such as diabetes, obesity, and infectious disease.
The discovery in animals of molecular profiles and biomarkers associated with distinct clinical presentations will provide new insights into veterinary diseases and may lead to the development of new diagnostic criteria, therapeutic targets, and prevention strategies. As such, predicting the future course and treatment of veterinary diseases may become easier than predicting the weather!