JAPAN - Man's best friend is suffering, too, from the heat this summer with animal hospitals in many parts of the nation reporting twice the usual number of cases of canine heatstroke.

Veterinarians are warning people of the danger to their dogs as some of the cases of heatstroke cases have been fatal.

More than 20 dogs have been treated for heatstroke or suspected heatstroke at the Yakan Veterinarian Clinic in Akashi, Hyogo Prefecture, more than double compared with the average year.

Dogs do not sweat but instead cool their bodies by panting, a vet at the clinic noted. Sudden increases in a dog's body temperature may lead to disturbed consciousness and death, the vet said.

Such dogs as pugs and bulldogs are especially vulnerable to death from heatstroke because their airways are narrow.

In Mihara, Hiroshima Prefecture, a French bulldog, believed to be a stray, was found collapsed on the side of a road recently and later died of heatstroke.

Anicom Insurance Inc., an insurance company for pets in Tokyo, paid 107 claims for canine heatstroke in July, compared with 83 such payouts in the same month last year.

"I want dog owners to pay attention especially when a dog breathes irregularly and its body temperature is higher than usual," said Yasutaka Hamatani, a vet at the clinic.

As preventive measures, it is effective to wet a dog's skin with water, keep indoor temperatures at 27-28 C and use cooling devices designed for pets, he said.