Croatian rescuers are praising a dog who protected his injured owner from freezing high up on a snowy mountain, keeping him warm for 13 hours in the dark until he could get medical attention. 

"Friendship and love between man and dog know no boundaries," the county's mountain rescue service wrote on Twitter this week, with a photo of the dog lying on top of his master on a stretcher. 

Rescuers say that late on January 1, more than 1700m up Mt Velebit on Croatia's Adriatic Sea coast, a man and his dog — an Alaskan Malamute called North — slipped and fell about 150m. 

The hiker seriously hurt his leg but the dog was uninjured and used its body heat to keep him warm as temperatures dropped after nightfall and rescuers strove to locate them. 

"[North] curled beside him and warmed him with his body," the rescue service's post said. "His loyalty didn't stop even when the rescuers came, he was one of us, guarding his man for 13 hours." 

Rescuers said the overnight operation was particularly difficult because of snow, ice and broken tree boughs that blocked access to the spot. A team of 27 took part in the rescue, reaching the pair around midnight and handing over the hiker to medics about 8am the next day. 

"This example could teach us all how to care about each other," the rescuers said.