Animals worldwide are developing chronic diseases once seen only in humans. Rising cancer, diabetes, and obesity in pets, livestock, and wildlife show how pollution, climate change, and lifestyle shifts are shaping health across species.
From house pets to sea turtles, animals across the world are now facing illnesses once believed to affect only humans. Rising cases of cancer, diabetes, obesity, and joint diseases in animals are painting a bigger picture: our shared planet is shaping the health of every species, not just ours.
Why Animals Are Getting Human Diseases
Scientists say genetics and the environment are working together to drive this silent epidemic. Pets selectively bred for appearance, livestock bred for higher productivity, and wildlife exposed to toxic environments all face increased risks.
Poor diets, pollution, sedentary lifestyles, and chronic stress — the same factors harming humans — are affecting animals too. For instance, more than half of cats and dogs are now overweight, a trend directly linked to rising diabetes cases. Even marine creatures are suffering: beluga whales show gastrointestinal cancers, and farmed salmon develop heart problems.
Environmental Change Is Making Things Worse
Climate change and pollution are amplifying disease risks across ecosystems. Warming oceans correlate with higher tumor rates in marine turtles and fish. In cities, pets breathe the same polluted air humans do, increasing their risk of obesity, diabetes, and inflammatory diseases.
Wildlife living in chemical-contaminated estuaries show liver tumor rates as high as 15–25%. Scientists warn that as habitats degrade and temperatures rise, animals will continue absorbing the pressures of a rapidly changing world.
A Unified Health Approach Could Protect All Species
Researchers from the Agricultural University of Athens propose a new model that connects animal, human, and environmental health — merging One Health and Ecohealth principles.
Their framework suggests solutions at the individual, herd, ecosystem, and policy levels. By understanding shared risks across species, scientists hope to create early-warning systems that flag environmental problems before they spread and help protect both animals and humans from rising chronic diseases. Their findings have been published by the Society for Risk Analysis in their journal Risk Analysis.