Both Levi Sadler, 16, and the dog, Daisy, are recovering with various injuries after surviving the attack Tuesday night in the Vancouver-area village of about 650.
Sadler realized there was something wrong when he heard Daisy screaming outside his window.
"It was terrifying, like a scream you hear in movies, coming from a dog," he said. "When I looked over, the cougar had its mouth completely around her neck. All I saw were Daisy's legs kicking and screaming."
Sadler jumped out the window, screaming as loud as he could. Initially, the cougar ran off and Daisy stood up.
"I was oblivious to the cougar," Sadler said. "I was looking at Daisy, just hoping she was OK."
Out of the blue, the cougar returned, jumping straight at the teenager.
"It almost clawed me. I felt the paws pass by my ear. I thought he'd cut my jugular to be honest. It was the most terrifying thing I've ever endured."
Sadler escaped by throwing himself back through his window, injuring his head in the process.
"My blood was pumping so much. I wouldn't have even cared if I was hurt. I was trying to get Daisy out of there," he said.
The cougar finally retreated when Sadler's father, Jason Sadler, came running after hearing screams.
"I didn't know who was hurt. I could hear the gut-wrenching scream of the dog — and then I heard my son scream," he said.
Daisy suffered multiple lacerations and bruising, requiring 100 stitches, but is recovering with the Sadler family.