Air Pollution and Your Pet in India: What the AQI Actually Means for Dogs and Cats

Every winter, the same question turns up in Indian pet parent groups, usually around the second week of November. Someone posts a photo of an AQI reading in the four hundreds and asks whether it is okay to take the dog out. The replies are split. Half say the dog will be fine because street dogs live in it. Half say keep him inside. Almost nobody has a number to point to.

That is because there isn't one. India's National Air Quality Index, published by the Central Pollution Control Board, was built for people. There is no Indian government guidance, no AWBI circular and no municipal advisory that tells you what AQI is unsafe for a dog or a cat. There is also, as far as we could find, no published Indian veterinary study on companion animals and air pollution.

So this article does the next best thing. It pulls together the research that does exist, most of it from outside India, and the reporting from Indian vets during the 2025 smog season, and turns it into something you can actually use on a Tuesday morning when the sky is grey and the dog is standing at the door with the leash in his mouth.

Does air pollution actually affect dogs and cats?

Yes, and the strongest evidence for it is recent.

In September 2025, a study published in the Proceedings of the National Academy of Sciences looked at roughly seven million veterinary visits in the United Kingdom, covering about 3.8 million individual cats and dogs between 2017 and 2022. The finding was straightforward. For every one microgram per cubic metre rise in average PM2.5 over the previous week, veterinary admissions rose by about 0.7 percent, for cats and dogs alike. Moving from very clean air, below 5 micrograms, to air in the 40 to 50 microgram range implied roughly 30 to 40 percent more expected vet visits.

Hold that number next to a Delhi winter. During the 2025 season, PM2.5 levels in the capital ran through a range that a British researcher would describe as extreme, and the study's own baseline of 5 micrograms is a level most Indian cities do not see on their best day.

The indoor picture has been studied too. Two studies out of National Taiwan University, published in 2018 and 2020, found that cats living in homes where PM2.5 exceeded 35 micrograms per cubic metre were significantly more likely to have respiratory disease. In dogs, the standout indoor factor was incense burning, which showed up more than twice as often in the homes of dogs with respiratory disease.

And closer to home, a 2024 pilot study in Veterinary World examined 76 street dogs in the Kathmandu Valley and found black carbon deposits in the lungs of 25 of them. Kathmandu is not Delhi, but it is the same broad problem: dogs breathing dirty air for years, and it showing up inside their bodies.

One honest caveat. The UK study measures vet visits, not confirmed diagnoses, and the Taiwan and Nepal studies are small. None of them were done in India. What they establish is a clear direction, not an Indian dose response curve.

Why your pet takes a bigger hit than you do

Three things stack up against them.

They breathe faster. A resting dog takes roughly two to three times as many breaths per minute as an adult human, so more air, and more of whatever is in it, moves through their lungs in the same span of time.

They breathe closer to the ground. Heavier particulate and road dust settle low, and your dog's nose spends the entire walk in that layer. A cat sitting on a balcony is in it too.

They walk when the air is worst. Most Indian pet parents walk before work and after work, which in most cities is exactly when traffic density and morning inversion push particulate to its daily peak.

Cats have proportionally narrower airways than dogs, which is part of why the Taiwan researchers saw such a clear indoor signal in cats specifically.

What AQI is safe for dogs and cats in India?

There is no official answer, so here is an honest one. The table below maps the CPCB's national AQI bands to sensible action for a pet. It is adapted from human public health guidance and from what veterinarians generally advise during smoke and pollution events. Treat it as a starting framework, not a standard, and treat your own animal's behaviour as the better signal.

AQI	CPCB category	Reasonable approach for dogs and cats
0 to 50	Good	Normal walks, normal play, no changes needed.
51 to 100	Satisfactory	Normal routine. Healthy pets are unlikely to notice.
101 to 200	Moderate	Fine for most pets. Shorten hard exercise for flat faced breeds, seniors and any pet with a known heart or lung problem.
201 to 300	Poor	Cut total outdoor time noticeably. Walk on quieter roads, away from traffic. Skip the long run and the fetch session.
301 to 400	Very Poor	Short outings for toilet breaks only. Move exercise indoors. Sensitive pets should be out for minutes, not half hours.
401 to 500	Severe	Outside only for as long as it takes. Everything else stays indoors, ideally in a room with a purifier running.

For reference, the CPCB's 24 hour PM2.5 breakpoints run from 0 to 30 micrograms per cubic metre for Good, up to 121 to 250 for Very Poor and anything above 250 for Severe. The World Health Organization's 24 hour guideline is 15 micrograms, which puts the gap between what is normal in India and what is considered clean globally into some perspective.

Which dogs and cats are most at risk

Flat faced breeds sit at the top of the list. Pugs, Bulldogs, Shih Tzus, Boxers and Persian cats already work harder to move air on a good day, and polluted air narrows the margin further. If you have one of these, the thresholds above should shift a full band earlier for you.

After that: senior pets, puppies and kittens whose airways are still developing, any animal with existing heart disease, asthma, collapsing trachea or chronic bronchitis, and, less obviously, very high energy dogs. A Beagle or a young Indie who runs flat out for twenty minutes is pulling far more air through his lungs than a dog ambling beside you.

Signs your pet is being affected

Watch for a dry cough that shows up in the evening, wheezing, gagging or reverse sneezing more often than usual, watery or reddened eyes, nasal discharge, less appetite and unusual tiredness after a walk that used to be easy. In cats, coughing is easy to miss because it can look like a hairball attempt that produces nothing.

Some of these overlap with kennel cough, allergies and viral illness, which is exactly why a vet visit is worth it rather than a guess at home.

Treat as an emergency and go to a vet immediately: laboured breathing, breathing with the mouth open in a cat, gums that look pale, grey or bluish, or any collapse. Those are not pollution symptoms to monitor. Those are now.

Should you still walk your dog when the air is bad?

Mostly yes, but differently. A dog who does not go out at all gets frustrated, and frustration has its own health cost. The aim is to reduce the dose, not eliminate the walk.

What generally helps: check the AQI before you go, the same way you check the weather. Walk when traffic is thinnest for your area, which in most Indian cities means later morning or mid afternoon rather than the 8am and 7pm rush. Pick the park or the internal colony road over the main road, because roadside particulate can be dramatically higher than the reading from a city monitor a few kilometres away. Keep it short and flat instead of long and fast, since a sniffing walk moves far less air through the lungs than a run.

One point of genuine disagreement worth flagging: some Indian veterinarians recommend shifting walks to the middle of the day, when the overnight inversion has lifted, while others argue for early morning before traffic builds. Both are trying to dodge the same peak. In practice, look at your own city's hourly AQI curve for a few days and pick the dip. It differs between Delhi and Bengaluru, and it differs between a colony road and a highway service lane.

Indoor air is half the problem

Indoor PM2.5 in Indian homes tracks outdoor levels closely, and then we add to it. Incense, dhoop, mosquito coils, cooking smoke from tadka and tandoor style cooking, and cigarette smoke all push indoor particulate up sharply, and your pet is home for far more hours than you are.

What is worth doing: run a HEPA purifier in whichever room the pet actually sleeps in rather than the drawing room nobody uses. Choose a unit with a genuine HEPA filter plus activated carbon, and avoid anything marketed as an ionizer or ozone generator, since ozone is a lung irritant in its own right. Cats are noise sensitive, so a quieter unit gets left running instead of switched off. Cut the incense and coils during peak season, or at least keep them out of the room the pet sleeps in. Keep windows shut on severe days, which is counterintuitive in a country where cross ventilation is the default answer to everything.

Also worth knowing: air purifying houseplants do not meaningfully reduce PM2.5 in a real room. The often quoted NASA research was done in sealed chambers, and the plant count required for a normal living room runs into the dozens. Some popular indoor plants, including pothos, are toxic to cats if chewed, so the trade is a bad one twice over.

The five minutes after the walk

This is the part most people skip. Particulate settles on your dog's coat and paws during a walk, and then he grooms himself, or your cat grooms him, and it goes in.

Wipe the paws and the coat with a damp cloth or a plain microfibre towel when you come back in. Water is enough and no scented wipes are needed, since fragrance adds volatile compounds you were trying to avoid. Wipe around the eyes if they look watery. Keep the water bowl fresh and full, because well hydrated airways clear irritants better than dry ones. And keep the pet's bedding washed through the season, because textiles hold dust well.

On pet masks: skip them. There is no established veterinary standard for a canine respirator, a mask that does not seal does nothing, and a mask that does seal interferes with panting, which is how a dog cools himself. Nobody credible recommends them.

What Indian vets actually saw in the 2025 season

This is where the abstract becomes concrete. During the 2025 winter, Indian news agencies reported veterinarians in Delhi seeing a distinct rise in animals presenting with lung congestion, coughing, fever and eye and nasal discharge, with individual clinics describing dozens of such cases over the course of a few weeks. Bird vets in east Delhi reported a parallel rise in eye irritation cases.

For context on the season itself: Delhi's AQI touched 428 on 11 November 2025, its first Severe day of that year, and peaked at 461 on 14 December 2025, which made it the most polluted day of that winter and one of the worst December readings the city has recorded.

A viral post from a Delhi pet parent that season, showing a Golden Retriever on a nebuliser with a chest X ray, did more to start this conversation among Indian pet parents than any study has. It should not take that.

City by city, briefly

Delhi NCR is the acute case, and Gurugram, Noida, Faridabad and Ghaziabad share the same airshed, so a Gurugram pet parent should plan exactly as a Delhi one does, roughly from late October through February.

Mumbai's winter air has deteriorated noticeably in recent years and no longer deserves its old reputation for being coastal and therefore fine. Kolkata sees a similar winter pattern.

Bengaluru, Pune, Hyderabad and Chennai are generally better, but better is not clean, and roadside exposure on a busy corridor in any of these cities can be far worse than the citywide number suggests. The route matters more than the city.

Quick answers

Is AQI 300 safe for a dog? No. At 300, keep outings short and functional, avoid hard exercise, and stay off main roads. For a flat faced breed or a senior, that threshold should be lower.

Do air purifiers help pets? A HEPA unit run in the room your pet actually occupies will reduce the particulate they breathe indoors. Avoid ozone generators and ionizers.

Does air pollution affect cats? Yes, and possibly more visibly indoors. Household PM2.5 above 35 micrograms per cubic metre has been significantly associated with respiratory disease in cats.

Why is my dog coughing in November? It could be pollution related irritation, but it could equally be kennel cough or something else. A cough that persists past a few days deserves a vet, not a guess.

Should I stop walking my dog completely? Almost never. Shorten, reroute, and retime instead.

Sources

• Jarvis, Deschenes, Jha and Radford, "The impact of air pollution on petcare utilization," Proceedings of the National Academy of Sciences, 30 September 2025.
• Lin et al., National Taiwan University, Journal of Veterinary Internal Medicine, 2018, and Veterinary Medicine and Science, 2020, on indoor air quality and respiratory disease in cats and dogs.
• Thapa et al., "A pilot study on the pulmonary anthracosis in stray dogs of Kathmandu Valley, Nepal," Veterinary World, March 2024.
• Central Pollution Control Board, National Air Quality Index bands and PM2.5 breakpoints.
• World Health Organization global air quality guidelines, 24 hour PM2.5 guideline.
• Press Trust of India reporting on veterinary caseloads during the Delhi smog season, December 2025.
• Cornell University Riney Canine Health Center and the American Veterinary Medical Association, guidance on pets during poor air quality and smoke events.

A note on why we wrote this

TailSetter makes pet accessories. We are not veterinarians, and nothing here replaces an examination by one. We wrote this because we went looking for an Indian answer to a question our own customers kept asking, found that no such answer existed, and decided that assembling one carefully was more useful than staying quiet.

If your vet disagrees with anything here, follow your vet. If you spot something out of date, write to us and we will correct it. We plan to refresh this page each October before the season turns.