Unlike humans, dogs wore their coats all year round and did not sweat, so they were at greater risk of heat stress, SPCA chief inspector Virginia Pine said. Dogs should not be taken for runs in hot weather, or left in cars, even for short periods.
''Dogs should not be in cars unless it's to go to the vet or a short trip.''
A dog's method of cooling itself was by panting or releasing saliva, and heat stress could kill it. In Central Otago, two dogs had died after being plunged into the Clutha River to relieve their heat stress after being taken for runs, she said.
Immersion in cold water caused heart problems for dogs, which ultimately killed them.
''Do not immerse dogs in cold water.
''Put it in the shade, give it water and place a wet towel over the dog or spray it with tepid water.''
If there was still concern about the animal's welfare, it should be taken it to the vet immediately, she said.
In Dunedin the SPCA was receiving at least two calls a day from people concerned about dogs being left in cars.
It was at least 10degC or more warmer in a car than outside and without water, it compounded the stress for dogs.
People needed to ensure their pets had enough shade and clean, fresh water.
