Dr. Goh, center, during surgery

In her work as an orthopaedic surgeon at the Colorado State University Veterinary Teaching Hospital, Dr. Clara Goh sees lots of dogs and cats of all sizes, breeds, and colors with broken or diseased limbs and joints. But the cat she operated on in late October, well, that was one big cat.

On Oct. 27, Dr. Goh, along with Dr. Matthew Johnston from the Zoological Medicine Service and veterinary technician Jennifer Tucker, traveled south to the Cheyenne Mountain Zoo in Colorado Springs. There, the team performed surgery on a mountain lion that had fractured his tibia while in his Cougar Canyon enclosure, a natural canyon habitat for the zoo’s mountain lion residents. Because it would have been stressful on the mountain lion to travel to Fort Collins for treatment, the CSU veterinary team went to the mountain lion.

And, while Dr. Goh is used to operating on cats, cougars present some confounding factors.

“The size of the cat definitely posed challenges,” said Dr. Goh, noting the male cougar weighs 120 pounds. “We had to use a larger plating system that is used in horses. Another challenge is the fact that it’s difficult to manage a mountain lion’s level of activity. You really can’t have the keepers taking him for a walk on a leash.”

Plate repair of the lion's fractured leg.

To create a system that was robust enough to withstand the mountain lion’s normal movements, the surgical team used two bone plates to stabilize and repair the bone. Cougars have large paws and proportionally the largest hind legs in the cat family, allowing them to manage great leaps sprint short distances and hunt via ambush. There’s a lot of power in the back legs.

“We certainly don’t want him to break or bend the implants while he is healing, and the two plates give additional stability to the bone, just in case he gets a little more active than we would like,” said Dr. Goh.

The veterinary team at the zoo managed the anesthesia with the assistance of Dr. Johnston during surgery while Dr. Goh, Dr. Stephen Crane, a Colorado Springs veterinary surgeon who assists the zoo on special cases, and Tucker attended to the fractured leg.

“Everything went really smoothly, and the veterinary team at the Cheyenne Mountain Zoo did a wonderful job with the anesthesia,” said Dr. Goh. “The cat is now being kept in his holding pen to hopefully limit the use of his leg while he heals, a process that typically takes about eight weeks. The zoo’s veterinary team will likely take X-rays in December to see how the limb is healing, and again once he is at the eight-week mark. If all heals well, he should be up and running in the new year.”