CINCINNATI — Walter, a 6-year-old warthog beloved by Cincinnati Zoo guests and workers alike, passed away on Saturday, the zoo announced Sunday.

Zoo officials said Walter “was behaving normally” until Saturday when he didn't eat all of his food. Vets examined Walter and discovered he had an enlarged bladder.

“Sadly, since he showed no signs of discomfort, there was no way to identify the problem before it was too late,” zoo officials wrote in their announcement on Facebook.

Walter first arrived at the zoo's Wildlife Canyon and also participated in its Wild Encounters program.

MORE: Raised by humans, the Cincinnati Zoo's Walter the warthog must adjust to living with animals

“He outgrew that role but continued to enjoy attention from visitors and responded enthusiastically when people called him by name when they saw him running around his home in our African Savannah,” zoo officials wrote.

