20-year-old Selat was in the top 10 percentile of oldest Komodo dragons in North America.

SEATTLE — Woodland Park Zoo’s geriatric Komodo dragon Selat has died.

The 20-year-old lizard was euthanized Tuesday after issues stemming from age-related osteoarthritis and joint deterioration became unmanageable.

“Unfortunately, his condition took a downturn in recent days,” Dr. Darin Collins, Woodland Park Zoo director of animal health, said in a statement. “The quality of Selat’s life was compromised so we made the humane decision to euthanize him.”

Large lizards can live up to 20-25 years in the zoo, and the 165-pound Selat was in the top 10 percentile of oldest Komodo dragons in North America, according to Woodland Park.

He had lived at the zoo for nearly 19 years.

As he aged, Selat began experiencing mobility issues in his joints and limbs, which was managed with oral medication and therapy, including laser treatments, acupuncture, and massage. In the last few weeks he was taken off-site to monitor his arthritis, and although veterinarians didn’t find any new problems, his condition recently took a downtown, according to Collins.

Komodo dragons are venomous, which prevents their prey’s blood from clotting. There’s only about 3,000 to 4,000 left in their natural range, which is limited to five islands in southeastern Indonesia. However, their population continues to be threatened by forest clearing, arson, and trapping of prey.