CINCINNATI (AP) — The Cincinnati Zoo says the father of its famous baby hippo, Fiona, has died at age 36.

The zoo says Henry had been struggling with health issues for months and lost hundreds of pounds. The zoo says the hippo had been in obvious decline the past few days and that staffers decided to euthanize Henry on Tuesday after concluding that the animal's quality of life wouldn't improve.

The zoo says the average life expectancy for a Nile hippopotamus such as Henry is 35 years.

Henry's decline came after Fiona became a social media sensation. Fiona was born six weeks early, but survived and thrived.

Henry had mated with 18-year-old Bibi at the zoo.

Zoo officials have said they are grateful for the community's support during "the toughest of times."