A horrifying number of pets are being left out to cook in Queensland's sweltering conditions with at least five dying and hundreds suffering severe heat stress in the past fortnight, says animal welfare group RSPCA Australia.

It said there were more than than 80 reports of animals in distress at the weekend alone as a heatwave pushed temperatures in the state into the high 30s and 40s.

A large dog died on Saturday when its "organs boiled" after being tied up to a clothesline with no access to shade. The dog was one of four confirmed heat-related animal deaths in the state over the weekend, including a bird that perished in a hot car.

The RSPCA said it was likely many more pets had died over the past fortnight because it had fielded more than 400 reports of animals suffering heat distress. "Often we don't hear the results of every case, but sadly we do think there were other deaths," RSPCA Queensland spokesman Michael Beatty said. "It's horrifying ... these last couple of weeks have been as bad as we have ever seen it."


Beatty said an alarming number of dogs had been become tangled on furniture after being tethered in hot backyards, while dozens of pets had been left inside hot cars. Canines had also been left to cook on steel ute trays and horses had been wandering around paddocks with rugs on their backs, he said.

In some cases, people even sat inside in the air-conditioning while their dog was left outside with no access to shade or water.

"Some people are simply not listening," he said.