The zoo has not lost many mammals in recent years. Although zoo officials could not compile an exact number, they said fewer than 10 mammals died in 2007.
A veterinary pathologist from the Johns Hopkins University conducted a necropsy on Gretchen, a standard procedure that will be used to help researchers understand more about giraffes, both those in captivity and in the wild. The results of those tests, which include blood work, will likely come back in a few weeks, Bronson said. Her remains will be cremated.
Gretchen lived more than twice as long as the median for captive giraffes in North America, but struggled daily with arthritis and swollen joints, problems that can be particularly vexing for giraffes. One 1996 study said such issues may be "partially hereditary."
Her foot and leg difficulties have been with her since birth. Records from the Denver Zoo, where she was born in May 1986 and lived for one year before coming to Baltimore, note "bleeding wounds" on her right hind leg and both forelegs, leading some to speculate that her mother might have stepped on her, an accident that is sometimes hard to avoid.
Veterinarians and keepers spent "thousands of hours" on many treatments to help her feel more comfortable, Gullott said, including hoof-trimming that likely added many years to her life. Keepers trained her to stroll into a complex giraffe restraint that facilitated many of the procedures.
She recently had received frequent injections of a joint "supplement" as well as anti-inflammatory drugs and pain medicine, and veterinarians even attempted acupuncture several times.
The Maryland Zoo is also treating a lesser kudu (an East African antelope) for severe arthritis in its front legs. Magnet the polar bear, several older monkeys, both the zoo's lions, a male wart hog, some birds and even a timber rattlesnake are being treated as well.
Bronson said it was unclear what reaction the other four giraffes would have to Gretchen's absence, but they would be monitoring females Mary, 21, Zoe, 14, and Angel, 12, as well as Cesar, a 2-year-old male.
While zoo workers would miss her, Gullott said, they also all agreed ending her life was necessary.
"We do have an affection and a bond with the animals we care for, but it's different from the one you have with your dog or cat at home," she said. "It's a profound respect for these different species. They're ambassadors for their wild counterparts. They help to educate people about conservation and the natural world. We never take it for granted, what we get to do every day, and it's tremendously rewarding, getting to know these animals, because they each have their own personality."
bradley.olson@baltsun.com
Sun reporter Frank Roylance contributed to this article.
