Er Shun and Da Mao arrived in Toronto in 2013, and were welcomed by Prime Minister Stephen Harper and his wife. They will be moved to the Calgary zoo in 2018 for a five-year stay before returning to China.
The father of the cubs could be one of three pandas, including Da Mao, after Er Shun underwent two artificial insemination procedures in May, the zoo said.
Panda twins were born at Washington's Smithsonian National Zoo in August, although one died of pneumonia within a matter of days.
The surviving cub was named Bei Bei by US First Lady Michelle Obama and her Chinese counterpart, Peng Liyuan.