Zoo Miami announced the death of its beloved black rhino, Toshi, on Friday.

Toshi was nearly 44 years old and was believed to be the oldest Eastern black rhino in North America and the second oldest in the world.

According to a news release, Toshi died due a variety of ailments that came along with advanced age.

Some of those ailments, including severe arthritis, were being successfully treated with medications, but zoo officials said the treatments became less effective as time went on.

According to the news release, Toshi experienced dramatic weight loss in recent weeks and became lethargic.

Veterinarians conducted tests on the rhino, but were unable to determine what was causing the weight loss.