Life-threatening danger for dogs after just a few minutes

The University of Veterinary Medicine Hannover appeals to pet owners not to leave dogs in cars in hot weather.

© Hannover.de

Summer is fast approaching: as temperatures rise, so does the danger for animals left behind in cars. After just a few minutes, a car can become a life-threatening heat trap. The University of Veterinary Medicine Hannover Foundation (TiHo) is appealing to all dog owners: never leave your four-legged friend in the car in hot weather!

A quick shopping trip, a quick trip to the parcel shop – even if the time seems short, the car heats up quickly. Even at an outside temperature of 20 degrees Celsius, the interior of the vehicle can reach 46 degrees after an hour. At 30 degrees Celsius, this value is exceeded after just half an hour. These temperatures can quickly become life-threatening for dogs!

Dogs in cars are particularly prone to overheating

‘Dogs are particularly prone to overheating in cars. They have very limited ability to regulate their body temperature,’ explains Professor Dr Sabine Kästner from the Small Animal Clinic at TiHo. ‘Unlike humans, they only have sweat glands on their paws and regulate their body temperature almost exclusively by panting. The evaporation surface is limited, so cooling quickly reaches its limit – especially when the ambient air does not circulate, which is the case in a closed space such as a car,’ says the expert.

Danger of heatstroke

What many people don't know: ‘A dog's ability to cool itself down by panting is already impaired when the ambient temperature exceeds 28 degrees Celsius,’ warns the vet. The risk of animals suffering heatstroke is therefore very high. The health consequences of overheating depend on the level of body temperature and the duration: if a dog suffers mild heat stress, which manifests itself in fatigue and heavy panting, and is cooled down in time, the prognosis is positive that the dog will recover and suffer no lasting damage. In the case of full-blown heatstroke, however, the animal's condition can quickly become critical.

‘We speak of full-blown heatstroke when the core body temperature exceeds 41 degrees Celsius,’ reports Kästner. ‘The animals show symptoms such as bloody vomiting and diarrhoea, and they have neurological deficits such as convulsions or loss of consciousness.’ If the body temperature rises to more than 43 degrees Celsius, heatstroke is usually fatal.

High mortality rate

Heatstroke poses a considerable risk to a dog's life: despite intensive medical treatment, the mortality rate among affected animals is 50 to 60 percent.

Brachycephalic breeds – i.e. short-nosed dogs such as pugs and bulldogs – older animals and dogs with thick coats, obesity or pre-existing conditions are particularly at risk.

Bringing an overheated dog to the vet's practice

It is important for Kästner to emphasize that an overheated animal should always be taken to a veterinary practice - even if it appears to have recovered. This is because heatstroke can also have long-term health consequences, including chronic kidney disease or functional impairment of the muscles and nervous system. "If you find an overheated dog, it is important to move the animal to a shady place as quickly as possible and cool it down. Air conditioning and ventilation can also help on the way to the vet," says the expert.

Do not leave dogs in the car in summer

"But even more importantly, dogs - and all other animals - should never be left in the car in summer," Professor Kästner urges all owners.

(Published: June 13, 2025)