A worker at the Granby Zoo in Quebec is being treated for serious injuries, including cuts to the lower body and a cervical fracture, after being mauled by a lion.

Paul Gosselin, the director of the zoo, located about 80 kilometres east of Montreal, said the woman was alone with the animal when the attack happened.

The attack has at least one expert questioning whether the zoo properly followed standard safety protocols for zoos.

The woman, in her early 20s, was bitten in the back while preparing the lion's food early Monday morning, Gosselin said.

Another zookeeper used carbon dioxide and a high-pressure water hose to separate the lion from the worker.

"We're still in shock about what happened," Gossellin told a news conference.

The incident happened shortly before 9 a.m., before the zoo had been opened to the public.

The injured worker, who has not been publicly identified, began working at the zoo in 2011.

Paul Gosselin is the director general at the Granby Zoo. 0:43

Stéphan Scalabrini, head of Granby's ambulance services, said the woman was in stable condition and conscious when she was treated at the zoo.

"The paramedic gave her treatment at the scene and transferred her to the hospital," he said. "She was awake and responding to everything."

'Highly unusual'

Gosselin​ said it's still unclear exactly what led to the attack. He said employees at the zoo "follow a very precise protocol" when working with lions.

But Ed Hansen, the head of the American Association of Zookeepers, said it's rare for zookeepers to enter an enclosure when an animal is present.

"It's very, very unusual for a keeper and a dangerous animal of any type to ever occupy the same space at the same time. It's not unheard of, but it is highly unusual," Hansen said.

Attacks on zookeepers happen roughly "once or twice year" in North America, he said.

In April, a zookeeper in Florida was killed by a tiger after she entered the big cat's enclosure. In May, a gorilla was shot dead after a three-year-old boy fell into an enclosure at the Cincinnati Zoo.

Lions kept inside following attack

Gosselin didn't say which lion had attacked the worker.

All three of the zoo's lions were kept inside and away from public view following the attack.

Earlier this year, the zoo welcomed two young lions to its grounds.

Granby Zoo veterinarians treated two young lions, Congo and Cécilia, after their arrival in April. (Granby Zoo/Facebook)

The zoo is home to some 1,500 animals, including 225 exotic species and 90 underwater species, according to its website.

The incident comes after a gorilla died suddenly at the zoo last month.

N'sabi, a 21-year-old lowland gorilla and long-time resident of the Granby Zoo, died following a brief illness.