How do veterinarians help a giraffe ease its arthritis pain? Well, it takes a little more than an aspirin and a gulp of water.

_­Recently, Colorado State University veterinarians traveled to Cheyenne Mountain Zoo[1] to help Mahali, a 14-year-old giraffe, with arthritis pain in his front left hoof.

Arthritis is a common problem for giraffes, especially geriatric giraffes like Mahali. Who can blame them? Weighing in at 2,000 pounds on average, their four feet support more than one ton of weight. That’s like carrying two grand pianos on your back all day.

With its 17-giraffe herd trained for voluntary husbandry, including hoof trims, blood draws and radiographs, Cheyenne Mountain Zoo is uniquely suited to help find better arthritis treatments for giraffes.

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Currently, arthritis in these megavertebrates is managed through corrective hoof trims, non-steroidal anti-inflammatories, cold-laser therapy and pain medications. But, these practices are not always enough to keep giraffes, which can live up to 30 years, comfortable as they age.

CSU veterinarians Dr. Val Johnson and Dr. Amanda Morphet, and the zoo’s lead veterinarian Dr. Liza Dadone, are determined to discover a more successful way to treat these gentle giants, and they believe stem-cell therapy is the answer.

“Stem-cell therapy has resulted in dramatic clinical improvement in some cases of arthritis in horses and other species, but has not, until now, been attempted in giraffes,” Johnson said.

The university and the zoo began working together seven years ago, when CSU veterinarian Dr. Matt Johnston and zoo veterinarians initiated a partnership to treat zoo animals while teaching veterinary students.

This specific stem-cell research partnership began in 2016, when Johnson and Dadone started treating a geriatric elephant for arthritis with stem-cell therapy.

Johnson, who is researching regenerative medicine at CSU, has safely treated a mountain lion, tiger, wolf, coyote and dogs with stem cells over the past five years.

“Regenerative medicine is a promising new avenue for treatment of chronic age-related degenerative diseases,” Johnson said. “I want to develop more effective methods for treating animals.”

Johnson and Dadone ran a crowdfunding campaign to develop a technique to grow stem cells from giraffe blood and grow multiple treatments of stem cells. The online campaign was quickly funded.

‘Mahali was in pain.’

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In April, Morphet and Johnson traveled with two CSU anesthesiologists, Dr. Marlis Rezende and Dr. Khursheed Mama, to Colorado Springs for the procedure on Mahali.

“Mahali was in pain. He wouldn’t leave pressure on his front left foot for longer than a minute or two,” said Morphet, who is training to specialize in exotic and zoo animal medicine at CSU’s James L. Voss Veterinary Teaching Hospital[4].

Mahali is trained for general footwork, but injecting stem cells requires absolute stillness. Anesthetizing a giraffe, however, is especially dangerous for the animal.

“With the length of the neck and limbs, falling during induction and recovery is a big concern,” Dr. Morphet said.

The large procedure room was packed tight with veterinarians, zoo staff and volunteers who assisted Mahali, which included repositioning his body, and elevating his head at different angles every 10 minutes to prevent muscle spasms, aspiration and brain swelling. The team of volunteers scooped sand under his back to help Mahali roll up once he awoke.

If this sounds like intense physical work, it is.

Veterinarians took radiographs and successfully injected stem cells while Mahali was anesthetized. Meanwhile, a farrier team trimmed his hooves.

The stem cells, which were grown from giraffe blood, were injected through a vein near Mahali’s inflamed hoof. The cells remained at the injection site for 20 minutes to improve absorption into the hoof.

Under the watchful care of veterinarians and zoo staff, Mahali came out of anesthesia safely. And then, they waited six long weeks for the stem cells to take effect.

Megavertebrate, mega results

This was the first time a giraffe has received stem-cell therapy to treat arthritis. The big question: Did it work?

Six weeks after the procedure, Morphet and veterinary students visited Mahali for a check-up.

“We’ve seen a dramatic improvement in his clinical signs,” Morphet said. “Not only to his comfort level but the quality of his hoof. He’s letting us work with his feet.”

Dadone, the zoo veterinarian, used a thermal camera to view the heat distribution in Mahali’s feet.

“With the thermal imaging, you can see hot spots in the limbs,” said Kara Gendron, a fourth-year veterinary student. “The warmer it is, the more likely it’s inflamed and painful. His left hoof was still a little warmer, but compared to what we were seeing initially, it was very similar to his right [hoof]. So, he’s actually doing a lot better.”