Gretchen, age 22, spent her last day of life at the Maryland Zoo in Baltimore atop the grassy hill where she had long endeared herself to thousands of families and children, grazing pleasantly with a herd of four other giraffes.
Staff members came to see her throughout the day Friday, offering tearful goodbyes to a sweet, inquisitive animal many had come to call "The Lady of the House."
Her long day outside was a rare one in recent weeks, zoo officials said, as her lifelong problems with arthritis gradually increased her suffering so much that they decided to end her life. Gretchen was euthanized yesterday about 9 a.m.
"This is a big loss for the Maryland Zoo and our community," said Don Hutchinson, president and chief executive of the Maryland Zoo, in a written statement. "Gretchen will be missed by all of us."
Animal keepers and veterinarians made the decision to euthanize her, having met occasionally this year to discuss Gretchen's condition, and all agreed that it was the most humane step, said Rebecca Gullott, the mammal collection and conservation manager, and Dr. Ellen Bronson, the zoo's senior veterinarian.
"We felt, up until very recently, that she was comfortable, that things were going fine," Bronson said. "It's a very progressive disease. For many years, she probably had no discomfort, ever. And then we saw occasional signs of discomfort where she had maybe a bad day. And recently, we saw she was getting more uncomfortable, and we especially saw it when the weather was bad. ... When the weather was rainy, like this past week, you could tell that she had more trouble moving."
Gullott said the signs were subtle but widely noticed. Gretchen's steps would be smaller and she moved more slowly. A petite giraffe at 14 feet tall and 1,400 pounds, her posture weakened and she shifted her weight while standing. Gretchen was still able to get up, but was less willing to leave the barn and had not been as active. She still ate plenty, they said, but that is often not the best indicator of physical problems.
Because animals such as giraffes are often preyed upon in the wild, they are biologically programmed to hide pain lest they be singled out by a lion, a fact that can complicate efforts to spot discomfort.
The procedure to end her life took about 30 minutes. Gretchen slowly and peacefully drifted into sleep with the help of a powerful anesthetic. The drugs used are the same ones employed for dogs and cats, although at a much higher dose.
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."
Sun reporter Frank Roylance contributed to this article.