Veterinarians across the UK are seeing more pets suffering heatstroke this summer, and many of these animals never left home. The Guardian reports cases of dogs, cats, and rabbits developing dangerous heat illness in gardens, pet carriers, and outdoor hutches. The problem goes well beyond the familiar warning about leaving pets in hot cars.

Dr Katharine Nelson from the Royal Veterinary College has noticed more dogs overheating in sun-exposed gardens or during car journeys, and cats suffering heat illness while trapped in carriers The Guardian. Dave Martin, head of welfare at Inspiring Vet Care, describes the same pattern: dogs lying in direct sunlight, cats in greenhouses, and rabbits in outdoor runs The Guardian.

The numbers tell the story. In 2025, Inspiring Vet Care handled 355 cases of suspected heatstroke in pets—66% of them in summer months. That's a 28% increase from 2024 The Guardian. Certain pets are at much higher risk: flat-faced breeds like bulldogs and pugs, thick-coated animals, and any pet with existing heart or breathing problems. These animals struggle harder to cool themselves down when temperatures climb. Nelson has even treated a guinea pig for heat stress, a creature almost never mentioned in heat-safety warnings.

This is happening as Europe faces extreme heat. Western Europe recorded its hottest June on record, with temperatures reaching 40°C or higher in Germany, France, and Spain The Guardian. In late June, temperatures across Europe approached 40°C, causing transport disruptions and widespread warnings Reuters. The impact on people was serious: at least 18 people died in France, including two children who died in a hot car Reuters. The heat also killed hundreds of thousands of farm animals in France, straining services that collect carcasses Reuters. France even restricted public alcohol consumption during the worst of the heat AP, while the UK had faced record early-season temperatures forecast to reach 34°C in May AP.

Most advice to pet owners focuses on one specific danger: leaving animals in hot cars. The RSPCA says a dog in a hot car is an emergency requiring a call to police RSPCA, and this warning extends to conservatories and caravans RSPCA. The charity also gives summer guidance on outdoor animal care RSPCA, including advice for horses: move them to shade and pour large volumes of water over them if they show signs of heat exhaustion RSPCA.

But what vets are now seeing doesn't match that guidance. The heatstroke cases they report happen in ordinary places: a dog napping in a sunny corner of the garden, a cat in a carrier during a short car trip, a rabbit left in an outdoor run on a warm afternoon. These scenarios fall outside the "hot car" warning that dominates public messages. For flat-faced breeds especially, the body's ability to stay cool fails quickly when the air temperature and humidity rise, regardless of whether the animal is in a vehicle.

It's unclear whether official guidance will change. But the pattern is hard to ignore. Western Europe experienced its hottest June on record, the UK is now facing its third heatwave in one calendar year, and vet clinics report steadily rising heatstroke cases year after year. This suggests that current pet-safety advice may not cover all the places where pets are now at real risk.