Two elderly apes. One very bad week.
That's about the only explanation Dr. Chris Hanley has for the rapid demise of two great apes at the Toledo Zoo over the past week, resulting in the death of a chimpanzee Friday and the death of a gorilla Tuesday.
Primates, like humans, can contract the H1N1 virus, Dr. Hanley, the zoo's chief veterinarian, said.
But there is absolutely no evidence Fifi the chimpanzee or Elaine the gorilla had that or any other flu virus, he said.
Both were well beyond their life expectancy and appear to have died from the natural aging process, Dr. Hanley said.
Fifi was 49. Chimpanzees in zoos typically live to be 32 to 34 years old. The major finding of her necropsy was enlarged blood vessels near her brain, which may indicate she either had experienced or was on the verge of suffering a stroke. More tests will be conducted over the next two to four weeks to help verify the cause of death.
Elaine was 42. Captive gorillas typically live to be 31. She had developed a dry, intermittent cough, a loss of appetite, and a little trouble breathing.
A test to determine whether she had the flu came back negative. Like Fifi, more tests are being done to help verify her cause of death. She had been responding to medication for a possible respiratory infection, then took a sudden turn for the worse.
"There's no indication right now there's any link between these animals dying," Dr. Hanley said. "There was no commonality other than two old apes dying together."
The two apes were housed in separate parts of the same building and did not make contact with each other. They received care from different keepers.
Fifi had been with the zoo since 1963. Zoo officials noticed something amiss when she exhibited signs of back pain and muscle weakness. She never had flu symptoms, Dr. Hanley said.
Elaine had been at the zoo since 1991. She showed signs of being tired, but not weak.
She trembled a bit and first appeared to have a respiratory infection. But test results on a throat culture were negative.
A necropsy performed Tuesday revealed abnormalities in Elaine's adrenal glands, kidneys, and lungs. "Her bloodwork suggested potential kidney failure," Dr. Hanley said, adding such findings would be consistent with the natural aging process.
Officials initially were encouraged by her response to treatment. But she was "minimally responsive" on Tuesday morning and died during recovery after being immobilized for an examination, the zoo said.
Anne Baker, the zoo's executive director, said it was difficult losing the animals.
"Caring for geriatric animals such as Elaine requires a special focus, and it's through the efforts of the animal care staff that our animals experience not only longevity, but also an excellent quality of life in their advanced years," she said.
Elaine was born in the wild. Although she had no offspring, she served as a surrogate mother to two young gorillas, the zoo said.
Even though neither ape appeared to have anything contagious, the zoo is looking for signs of H1N1 or other types of flu, Dr. Hanley said.
Keepers take additional precautions to wash their hands and remove germs from their footwear, he said.
The public should not fear exposure to any virus that might show up at the zoo. Most animals are behind glass, Dr. Hanley said.