The Milwaukee County Zoo expressed sadness in a Facebook post today.
31 year-old Cassius, a western lowland gorilla, passed away Thursday night.
In a phone conversation with the Zoo, officials told Local 5 that Cassius had been with them since 1998.
Zookeepers noticed Cassius was not interested in food and water for the last day-and-a-half. As a result, veterinarians performed an exam including a cardiac ultrasound and electrocardiogram.
Officials say the exam indicated decreased liver and kidney function and that the heart may not have be contracting fully.
Sadly, Cassius died overnight.
The Milwaukee County Zoo explained that Cassius was the protective father of Zahra and Sulaiman.
The family group will be off exhibit so staff can monitor them as they adjust without their calm leader.
View the Milwaukee County Zoo’s post below: