DALLAS (CBSDFW.COM) — The Dallas Zoo took to social media Friday to announce the sudden death of 24-year-old silverback gorilla Subira.

Subira (Courtesy: Dallas Zoo)

The nationally-acclaimed zoo said Subira was being treated for a mild cough in the days leading up to his death, but zoologists had no reason to believe that the cough was indicative of “anything more than a common cold.”

“We are devastated to share the news that our silverback gorilla, Subira, passed away recently at 24 years old. This huge loss came at a difficult time for our Zoo family, just as we were faced with closing to the public, but we felt it was important to share this with you.”

However, officials said Subira’s necropsy and preliminary pathology results revealed his cause of death to be cardiovascular disease.

“Heart disease is the number one cause of death for male gorillas, which is why our males receive regular wellness checks, including bimonthly heart rate tests as well as a more intensive ultrasound procedure every three years. We have also been working with the Great Ape Heart Project, based at Zoo Atlanta, for the last 10 years to stay at the forefront of causes, research, and preventative measures we can take when it comes to our great apes’ heart health.”

Subira’s last heart ultrasound was conducted in 2018 and showed no signs of heart disease, and his latest heart rate measurements had all been normal, the zoo said.

Given his cough, experts were also “incredibly sensitive to concerns about COVID-19.”

And although the CDC has not received any reports of animals becoming ill from this disease, the zoo worked with local and state officials and were able to confirm earlier this week that Subira was negative for the virus.

“We know your hearts are hurting, along with ours, for our gorilla family troop. It’s going to take some time for Megan, Shanta, Saambili and Mbani to adjust to life without Subira, but our troop is resilient. Megan, who has always favored Subira, has been seeking comfort and staying close by Shanta’s side, and both girls have been keeping the little ones close. Everyone is doing well, and the whole family has been spending time in the habitat to enjoy the sunshine this week.”

The zoo said Subira was a loving, patient and gentle silverback, and will be dearly missed.