Not just humans, animals too bearing the brunt of toxic haze in Delhi

As Delhi’s air thickens each winter, most conversations around pollution focus on human health. But the city’s invisible victims — animals that share our air — suffer quietly from the same toxic haze.

Dr Ajay Guliani, a Delhi-based veterinary surgeon, says respiratory distress is the most common problem he encounters in animals during the smog season.

“Animals develop throat irritation, coughing and wheezing, and if left untreated, even asthma,” he explains. “Those living on the streets — dogs, cows and buffaloes — are the worst-hit because they are constantly exposed without protection or shelter,” he said.

Long-term exposure, he adds, doesn’t just cause breathing issues. “Pollutants inhaled over time can trigger cardiovascular problems and even genetic damage,” Guliani says. “These chemicals can alter DNA, leading to poor breeding and birth defects,” he says. He also points out that the lifespan of stray animals is often shortened by several years compared to those kept indoors.

Dr Mini Aravindan, Senior Director of Veterinary Affairs at PETA India, an organisation that works for animal protection, says the effect of air pollution on animals is similar to that on humans — ranging from irritation of throat, nose and eyes to coughing, gagging and difficulty breathing. “In addition to damaging the lungs, polluted air can also affect the heart. Prolonged exposure weakens immunity and can cause reproductive failure and other diseases in animals,” she explains.

She notes that long-term exposure to poor air quality can reduce lung function and lead to premature death. She explains that pollutants interfere with reproduction in countless ways — they can affect hormone production, disrupt mating cycles and even alter parental behaviour or food availability.

While household pets often have the advantage of cleaner indoor air or air purifiers, Aravindan points out that stray animals face greater risks. Among species, breathing-impaired dog breeds are especially vulnerable. “French and English bulldogs, pugs, boxers and shih tzus already suffer from a condition called brachycephalic syndrome that makes breathing difficult,” says Aravindan. “Air pollution worsens their suffering.”

PETA India has urged the government to prohibit the breeding of such dogs under the Prevention of Cruelty to Animals (Dog Breeding and Marketing) Rules, 2017.

Wildlife, too, is not immune. According to Wildlife Researcher Dr Fayaz Khudsar, the impact of air pollution on free-ranging species such as birds and small mammals is “complex and under-studied.”

“It’s difficult to isolate pollution from other environmental stressors,” he explains. “We know that exposure causes respiratory tissue damage and even neurological disorders due to heavy metal poisoning, but we lack long-term or species-specific studies in India to understand the scale of the problem.”

Khudsar adds because wild animals constantly move across habitats, monitoring their health impacts is challenging. While pollution contributes to chronic stress and disease, Khudsar clarifies that no direct deaths of wild animals in Delhi have been recorded so far due to air pollution. “But the real concern is long-term,” he says. “Decline in breeding success, changes in genetic health and disrupted behavioural patterns can affect populations in ways that may not be immediately visible,” he says.

He also points to indirect impacts. “Visibility issues from haze can disrupt bird migration, leading to confusion in navigation,” Khudsar says. “Some birds land in unsuitable wetlands, where they face predation or lack food,” he says.

Pollution also seeps into ecosystems. “Heavy metals and microplastics accumulate in soil and water, entering grazing livestock and aquatic species,” he explains. “Over time, these toxins move up the food web, affecting larger animals, including humans,” he adds.