Why Cats, Dogs, and Even Whales Are Getting Human Diseases
Chronic diseases like diabetes, cancer, and arthritis aren’t just human problems anymore—they’re showing up across the animal kingdom, from our household pets to the depths of the ocean. A new study published in Risk Analysis by animal scientist Antonia Mataragka from the Agricultural University of Athens reveals just how deeply our shared environments and lifestyles are affecting animal health—and why veterinarians are key to reversing this trend.
The Rise of “Human” Diseases in Animals
Around the world, animals are developing non-communicable diseases (NCDs) once thought to primarily affect people. Dogs, cats, dairy cows, and even sea turtles are increasingly being diagnosed with diabetes, obesity, cancer, and joint disease. The study found that both genetic factors and environmental pressures are driving this rise.
Selective breeding for appearance or productivity has left many animal populations genetically predisposed to disease. For example, purebred cats and dogs face higher risks of conditions like diabetes and mitral valve disease, while livestock bred for high yield often struggle with metabolic and orthopedic issues.
But it’s not just genetics—our shared environment plays an equally damaging role. Poor nutrition, lack of exercise, and chronic stress are now recognized as cross-species risk factors for chronic disease.
A Global Epidemic with Local Impacts
The statistics are sobering:
More than half of cats and dogs in the U.S. are obese, driving up rates of feline diabetes and orthopedic problems.
Around 20% of intensively farmed pigs develop osteoarthritis.
Beluga whales are showing gastrointestinal cancers, and farmed Atlantic salmon are developing cardiomyopathy.
Wildlife exposed to industrial pollutants such as PAHs and PCBs have liver tumor rates as high as 25%.
The study also found that climate change and urbanization are accelerating disease emergence. Rising temperatures, air pollution, and habitat loss are increasing stress and exposure to harmful substances—creating a perfect storm for chronic illness in both animals and humans.
The Missing Link: Veterinary Surveillance
While the World Health Organization tracks NCD data in humans, there’s no equivalent global system for animal health. That lack of surveillance means diseases often go undetected until they’re advanced—costing both lives and resources.
“As environmental changes accelerate disease emergence, the absence of early diagnostic systems further delays the detection of NCDs in animals,” Mataragka explains. “We need more comprehensive research and enhanced surveillance in veterinary health to better understand and address these issues.”
A One Health–Ecohealth Future
To close this gap, Mataragka proposes a new interdisciplinary framework that unites two complementary approaches: One Health and Ecohealth. Together, they emphasize the interconnectedness of human, animal, and environmental well-being.
Her model identifies prevention strategies at four levels:
Individual: Encourage balanced nutrition and exercise for pets and livestock.
Population: Improve breeding practices and herd health monitoring.
Ecosystem: Reduce pollution, protect habitats, and mitigate climate stress.
Policy: Develop unified health databases and early-warning systems for animal disease.
Why It Matters for the Veterinary Profession
Veterinarians are uniquely positioned to detect early signs of chronic illness and to advocate for healthier ecosystems. By embracing a One Health mindset, the profession can help prevent diseases that cross species lines—protecting not only animal patients but also the environments and communities they live in.
The takeaway? Chronic disease isn’t just a problem for people—it’s a planetary issue. As veterinarians, understanding these shared risks gives us the opportunity to lead the way toward healthier animals, healthier ecosystems, and a healthier world.
