Cheyenne Mountain Zoo officials didn’t want to “wait too long” to end giraffe Penny’s pain, zoo President and CEO Bob Chastain said Tuesday, explaining the sudden decision to euthanize the 8-week-old calf.

So although the decision was difficult, it was the kindest choice, Chastain said.

“In my experience, we tend to wait too long for our pets,” he said. “I don’t believe we waited too long. But had we gone any further, it would have been too much.”

Penny’s euthanization Monday evening shocked her thousands of concerned fans, many of whom had watched her birth June 4 on the zoo’s giraffe “Birth Cam” and had followed her health problems in news reports and on social media, where her videos received nearly 8 million views.

Even the zoo’s staff had been optimistic before Penny arrived at Colorado State University in Fort Collins last weekend for advanced veterinary care. CSU is home to the renowned College of Veterinary Medicine and Biomedical Sciences.

Veterinarians were prepared to perform surgery on her infected leg when they discovered that Penny’s abscess had spread from her hip bone to her abdomen, and she had a dislocated hip and degenerating femoral head, the top of the thigh bone, forcing her to stand awkwardly. In addition, her white blood cell count was rising despite treatment with antibiotics.

“I was prepared to know the trip would be dangerous, and the anesthetic was dangerous,” Chastain said Tuesday. “I was not prepared for the situation to turn as bad as it did.”

Penny’s legs splayed when she was only 9 days old, starting the chain of health problems that plagued her.

Although femur bones have been successfully replaced in ponies and miniature horses, only one horse weighing more than 880 pounds ever survived the operation. Penny weighed 181 pounds a week ago, said zoo spokeswoman Jenny Koch. And a giraffe’s bone is much longer than that of a horse, complicating the procedure.

The veterinary case of Penny, the 200th giraffe calf born at the zoo, will be used to further giraffe medicine, as a team of zoo staff members and a CSU veterinarian travel to Uganda to help giraffe conservation and protection efforts there.

The giraffe building was to be closed to the public Tuesday and Wednesday to give zookeepers privacy, but flowers and cards were being left there for the giraffe keepers. Memorial gifts can be contributed at cmzoo.org/helppenny.