Arguably, the most revolutionary scientific discovery of the 21st century is the genome mapping of humans and various plant, animal and microbial species. Scientists use the maps to expose secrets buried in the slight variation of DNA between individuals and to explore how environmental factors affect gene expression. Ultimately, this knowledge is changing how we live, from groundbreaking medical treatments to advanced strategies in agriculture that will help feed a growing world population. The best part? We’re just scratching the surface. DNA technology is here to stay and will be monumental in how veterinarians practice medicine.
DNA testing and the integration of genomics into personalized veterinary care are becoming a reality. The declining cost of DNA sequencing equates to more data available for research and more accuracy in our knowledge about how genetic variants impact clinical disease. In addition, new technology platforms such as liquid biopsy usher in more options for early cancer detection. Identifying specific mutations within cancer tumor cells implies which therapies might provide the best treatment option. Meanwhile, some microbiome applications are progressing from research to commercialization, especially in dental health and nutrition.
Genomics is a vast field of study. Although we have much to learn, now is a pivotal time for veterinarians to be attuned to this emerging area. Adopting innovative technologies can help veterinary hospitals provide the best medicine possible and make recommendations about the optimal quality of life for patients and their families.
Building Rapport
Veterinarians and their teams sometimes have preconceived notions of diseases a patient could be at risk for, so they issue recommendations based on the assumptions. For instance, the new owners of a dachshund puppy might be instructed to use a harness instead of a collar and install ramps in the house to avoid the manifestation of intervertebral disc disease. However, does the same conversation take place with the owners of a new Corgi or poodle? What about mixed-breed dogs with short legs and long bodies? An increased genetic risk for IVDD has been found in several chondrodystrophic breeds beyond dachshunds.
Preparing for how IVDD might progress can benefit the pet owner and veterinary team. Additional client education can ensure that patients are treated promptly with anti-inflammatories and get cage rest at the earliest clinical signs.
Speaking of preconceived notions, veterinarians sometimes make assumptions about behavior based on a dog’s breed or appearance. Recent research by UMass Chan Medical School and the Broad Institute of MIT and Harvard found that many genetic loci influencing behavior were not associated with the breed. Rather than relying on generalities, practitioners could glean insight directly from a dog’s DNA.
Diet is another critical part of at-home pet care. Pet owners often look to their veterinarian for information when selecting the best food from myriad options. Understanding the genetics behind conditions such as urinary stones, heart disease, kidney disease and pancreatitis could indicate specific dietary recommendations.
Risk awareness also can help clients be financially prepared, either by acquiring pet health insurance or saving for potential expenses. In addition, positioning genetic health testing as an important part of a new pet’s medical history creates a solid foundation for building the client relationship. It allows the veterinarian to supply specific education and resources, empowering pet owners to provide excellent care.
Always Be Prepared
The unexpected loss of a patient during surgery or post-op can devastate the veterinary team and client. Unfortunately, such situations also can bring negative social media attention to a hospital or even litigation. So, why not address potential adverse events linked to identified hereditary conditions during routine pre-anesthetic screenings?
For example, we know of nearly 20 genetic mutations that impair a dog’s ability to coagulate. The impact of these variations ranges in severity, but some might not be evident during a physical exam or bloodwork and could be life-threatening after a routine surgical procedure. Early awareness of these risks could enable pre-treatment with desmopressin (von Willebrand’s disease) and plasma transfusions to help prevent complications.
Furthermore, genetic mutations can hamper an animal’s ability to metabolize commonly used drugs properly. Malignant hyperthermia, for example, is caused by a genetic mutation in the RYR1 gene and has been observed in several dog breeds. Clinically, the condition is undetectable until the dogs are exposed to a chemical trigger such as anesthetic agents (halothane, isoflurane, desflurane and sevoflurane) or certain depolarizing muscle relaxants, like succinylcholine. The reactions can be deadly, but with awareness of the underlying genetic condition, different anesthetic protocols can be safely implemented.
Another genetic mutation that affects drug metabolism can occur in the ABCB1 gene (previously known as the MDR-1 gene) and results in increased sensitivity to macrocyclic lactones, certain chemotherapy drugs, and sedatives such as acepromazine, butorphanol and loperamide (Imodium). High doses of macrocyclic lactones for indications such as mange can still be an issue — hence the adage “White feet, don’t treat” — but recommended dosages of macrocyclic lactones for heartworm prevention in dogs with the MDR-1 mutation are generally considered safe.
Genomics Is for a Lifetime
Genetic health-risk testing is perhaps most beneficial after a pet’s birth or when a pet with an unknown medical history is adopted. However, insights from the data can be helpful throughout the animal’s life, as some degenerative conditions might not manifest until later.
One example involves ocular conditions with a genetic component, such as progressive retinal atrophy, glaucoma and lens luxation. Applying additional focus to the ophthalmic exam during wellness visits can identify early pathologic changes. Working together, the veterinary team and pet owner can manage pain and discomfort in pets with partial to total vision loss. Even simple environmental changes, such as carefully rearranging furniture, can go a long way in providing a better quality of life.
Simply put, technology is positioning genomic solutions as informative and affordable tools in the spectrum of care. Although DNA can reveal disease risks, the information need not be intimidating or scary. With the help of the veterinary team, DNA results can translate into actionable steps to provide the best care for pets in the hospital and at home.
As we continue to unlock the secrets of the genetic code and how DNA is expressed, the treasure will lie in how we use and apply that knowledge to support the veterinarian-client-patient relationship and drive compliance with goods and services that are in the best interest of the pet.
GENOMICS AT WORK
Embark Veterinary Inc. launched a genetic screening test for dogs in 2022. A veterinarian collects DNA samples and sends the swab to Embark for analysis. According to the company, a 2021 pilot study found that “70% of the dogs tested had actionable health results that resulted in modified care plans.” Other DNA test companies include:
- Cancer: PetDx, Vidium Animal Health, Volition Veterinary
- Hereditary conditions: Wisdom Panel, Basepaws, Paw Print Genetics, Neogen, Orivet, Animal Genetics, VetGen
- Other: MiDog, EpiPaws, AnimalBiome