A 17-year-old Siberian tiger is the latest animal to die at the Toronto Zoo.
Tonghua died Sunday around 8:30 p.m. as he was coming out of sedation. Zoo veterinarians had tranquilized the 400-pound cat to run a battery of tests after he began "acting a bit strange," staggering and refusing food on the weekend.
Dr. Bill Rapley, the zoo's executive director of conservation, education and research, said the initial tests and an autopsy conducted Monday indicated Tonghua had liver disease and possibly cancer. A firm cause of death won't be confirmed for a few weeks.
Until last weekend Tonghua "was always a bright, active, noble kind of animal," Dr. Rapley said.
Tonghua was born at the Zurich Zoo in 1993 and came to the Toronto Zoo a year later. He fathered nine cubs with two females.
The average lifespan of a Siberian tiger in captivity is 16 to 20 years, Dr. Rapley said.
"We are very saddened at the death of our Siberian tiger, especially in the year of the Tiger," said Councillor Raymond Cho, the chairman of the Toronto Zoo board.
The zoo currently has one other Siberian tiger, a 14-year-old female named Tatiana. The zoo also has four Sumatran tigers: A male, a female and two offspring of that pair.
Dr. Rapley said he expects a new breeding pair of Siberian tigers will eventually be brought to the Toronto Zoo.
"We have no plans not to have Siberian tigers at the zoo," Dr. Rapley said. "We might have a slight hiatus ... Then we'll bring new young ones for breeding."
The zoo has been the target of criticism recently because the death of the zoo's matriarch elephant in December has left only three pachyderms in the zoo - the minimum number considered healthy.
Councillor Giorgio Mammoliti, another member of the zoo board, reiterated Thursday that the facility has no intention of getting rid of exotic animals such as tigers and elephants.
"There's no zoo without exotic animals," he said. "This movement that seems to be all over North America to get rid of zoos is irritating to say the least."