Photo: Flickr user Max Braun

The oldest member of the bison herd in San Francisco’s Golden Gate Park was euthanized today.

The health of the 28-year-old bison known as Pretty Old Cow had been declining, according to a press release from the San Francisco Zoo, which provides veterinary care for the bison:

Sadly, the second of what was a herd of five female American bison, living in a spacious meadow in Golden Gate Park, was euthanized today. In a collaborative partnership, the Recreation and Parks Department maintains the bison meadow, and daily care and veterinary services are provided by the San Francisco Zoological Society. Today’s bison are descendants of a 1984 birthday present to former San Francisco Mayor Dianne Feinstein from her husband, Richard Blum.

The twenty-eight-old bison know as Pretty Old Cow was being monitored by Zoo Animal Care staff and veterinarians for the last few months. She consistently lost weight and voluntarily isolated herself from the other three female bison.  Because she had difficulty walking and exhibited signs of extreme stiffness, she laid down and showed no interest in food or water. Because her life expectancy and quality of life had rapidly diminished, she was euthanized this morning.

The largest living animal native to North America, American bison were brought to Golden Gate Park in February, 1891 by the Park Commission. At the time, bison were on the brink of extinction. The thriving herd gave birth to more than 100 calves as part of a nationwide captive breeding program; more than 200,000 bison now exist and are protected in their natural environment in Yellowstone National Park.

A 20-year old bison from the Golden Gate Park herd was euthanized July 5.