The Cherry Brook Zoo in Saint John was forced to euthanize one its animals this week — a Siberian tiger named Nyla.
In a news release, the zoo said the six-year-old tiger became suddenly ill on July 18.
Over several days, veterinarians — including one brought in from Toronto — tried to nurse the animal back to health. The veterinarians had trouble diagnosing the cat as she continued to lose weight and become increasingly lethargic.
After efforts failed, they were forced to put Nyla down on Wednesday.
Zookeeper Shyanne Polley looked after Nyla for five years.
"When you're working with large animals you have to respect them and you try to put a boundary between the two of you. But with her it was really hard. The attachment was impossible not to have with her," she said.
Linda Collrin, director of zoo development, said the staff are devastated.
"I'm heartbroken, it's the only way to say it, and I think shocked. Our cats live into their twenties, so to lose one at six years old that — she was fine, the day before. She was playing, she was running," she said.
Tigers are featured prominently in the zoo's marketing.
A post-mortem on Nyla determined she suffered from pneumonia but it's not clear how the seemingly healthy cat contracted the affliction.
Nyla is not the first Siberian tiger to die at the zoo. In 1996 a tiger named Pearl died after developing stomach problems and had to be put down.
Six years prior to that, a 17-year-old female named Meeshal died of old age.
Siberian tigers, which are also known as Amur tigers to more accurately reflect the Amur Region in southeastern Russia from which the species originates, are the world's largest cats.
During the 1940s the tigers were brought to the brink of extinction with less than 40 individuals in the wild. Anti-poaching laws and other conservation efforts brought the population back and the wild population of Siberian tigers appears to be holding steady at about 450 individuals.
In July, Moncton's Magnetic Hill Zoo announced that it is planning to start construction on a new tiger exhibit in 2014. There has not been a tiger at the Moncton zoo since the facility's mascot, 19-year-old Tomar, died due to complications from kidney failure in 2007.