Another animal has died under the care of the Dallas Zoo. According to a statement, Hope, a 23-year-old Western lowland gorilla, passed away suddenly on November 3.

The statement says that Hope and other members of the family troop of gorillas had been experiencing "mild gastrointestinal symptoms recently," which animal care staff were monitoring, including testing for parasites and other pathogens such as Salmonella.

But an initial necropsy showed that Hope's colon was "severely inflamed"; additional testing is pending.

Inflammation of the colon is treatable — unless the intestines swell and rupture, which can cause death.

In the wild, gorillas eat mostly leaves with lots of fiber. According to a study by the Journal of Nutrition, captive gorillas fed a low-fiber diet were prone to severe ulcerative colitis.

The Dallas Zoo, which claims to be committed to protecting this species in human care and in its native habitat, now sees its collection of gorillas shrink from 10 to nine. That includes a group of male gorillas who live on the south side of the Gorilla Trail, and a "family troop" who live on the north side that also includes Megan, another female who gave birth to a baby gorilla named Mbani in March 2019.

Hope leaves behind Saambili, a one-and-a-half-year-old baby gorilla born in July 2018. Infant gorillas are not fully weaned until they're 3 to 4 years old.

Hope was shipped to the Dallas Zoo in February 2017 as part of the Association of Zoos and Aquariums' (AZA) chessboard Species Survival Plan, for breeding purposes. Saambili was her second offspring; she delivered her first in 2004 at the ABQ BioPark Zoo in Albuquerque, New Mexico.

Gorillas can only give birth about once every four years. The average lifespan of a gorilla in the wild is between 30 and 40 years, according to the Smithsonian's National Zoo and Conservation Biology Institute.

Hope is the latest in a long series of animal deaths at the Dallas Zoo:

• Ola, an 8-year-old female African painted dog, was killed in July 2019 by two other painted dogs, less than a month after she was transferred to the zoo.
• Witten, a 1-year-old giraffe, died in June 2019 during a physical exam under anesthesia when he suddenly stopped breathing.
• Adhama, a baby hippopotamus, mysteriously died in 2018.
• Kipenzi, a baby giraffe, died in 2015 after running in her enclosure.
• Kamau, a young cheetah, died of pneumonia in 2014.
• Johari, a female lion, was killed in front of zoo spectators in 2013 in a similar scenario by male lions with whom she shared an enclosure.