The dog days of summer aren't really good days for dogs at all. In fact, high heat and humidity can be a deadly combination for dogs.

Dr. Jeff Nunez has seen what he considers an unusually high number of heat stroke victims this summer at Triangle Emergency Veterinary Clinic in Durham.

"It's such a serious disease the prognosis on it sometimes can be quite poor," he said. "Probably less than 50 percent of the dogs that come in with severe heat stroke survive."

Nunez said sudden temperature spikes make it hard for dogs to regulate their body's heat. Like people, dogs can go into shock when their bodies overheat. Other symptoms include disorientation, excessive panting, and vomiting.

"I think people oftentimes notice it, but they think it'll get better with time," he said. "They say, wow, my dog's acting a little strange, well, I'm just going to watch it for a few hours and see what's happening. I think that's the biggest mistake people make."

As a professional dog walker, Lucy Moore is paid to keep an eye on other people's pets. Despite the animal's enthusiasm for being outdoors, she tries to limit their exposure on hot days.

"I usually do 25 to 30 minute increments for a walk on a nice day," said Moore. "On days with excessive heat, I'll abbreviate that by about half."

Nunez said heat stroke can happen in a matter of minute. Dogs with any types of respiratory problems are particularly sensitive to heat stroke, even on days that aren't excessively hot.