WATERTOWN, S.D. (KELO) — A 10-year-old white wolf has died, the Bramble Park Zoo announced Saturday.

In a Facebook post, the zoo said a decision to humanely euthanize Trigger the wolf was made earlier this week.

Zookeepers said the decision came following medical examinations and consultations with veterinarians. According to the zoo, Trigger was losing weight rapidly, reluctant to eat, experiencing behavior changes and was removing himself from the pack.

Trigger was born on April 23, 2012, and had just celebrated his 10th birthday.

Zookeeper Olivia Wulff said Trigger will be deeply missed at the zoon.

“As animals grow older and sometimes unwell, it makes our jobs difficult as caretakers but we are with them until the end,” Wulff said.