WASHINGTON (AP) — The National Zoo in Washington says one of its three Sumatran tigers has had to be euthanized.

The zoo says 19-year-old Soyono was euthanized Monday. The Washington Post reports she was walking more slowly and seemed to be having trouble with her balance. She appeared to be suffering from a degenerative spinal disorder, and officials made the decision to euthanize her. At 19 she lived longer than most tigers do in the wild.

Soyono was born at the zoo in 1993 and gave birth to seven cubs. Her mate Rokan had to be euthanized in 2010, also at the age of 19.

The zoo’s two remaining Sumatran tigers are Kavi, a male, and Damai, a female.

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