Animal keepers at the Smithsonian’s National Zoo describe Asian elephant Shanthi as smart, loyal and steadfast. At 44 years of age, she is also considered an older elephant by Association of Zoos and Aquariums standards.
Like many aging animals, Shanthi has osteoarthritis, a degenerative disease affecting joint cartilage and the underlying bone with associated pain and stiffness. She was first diagnosed with the chronic condition in her carpi (wrists) when she was in her teens, and Zoo keepers and veterinarians have spent decades successfully managing her disease with multi-modal therapies. While arthritis does not have a cure, animal care staff continue to implement innovative ways to control Shanthi’s condition, ease her discomfort and improve her overall quality of life.
In March 2016, Zoo veterinarians collaborated with an equine veterinarian, Dr. Paul Anikis, to decrease the pain and inflammation in Shanthi’s joints using an innovative therapy called Interleukin-1 Receptor Antagonist Protein (IRAP), which has successfully slowed the progression of osteoarthritis for horses and people.
In preparation for these procedures, Shanthi’s blood was collected and then centrifuged, separating the blood cells from the plasma, which naturally contains the IRAP. The plasma was then frozen to negative 80 degrees Celsius, thawed and injected into Shanthi’s wrists. At the same time, Legend—a hyaluronic acid medication—was administered intravenously to aid in joint lubrication and decrease inflammatory markers within the joint. During Shanthi’s initial treatment, she received a series of IRAP injections in each forelimb. At that time, she underwent three separate procedures for each limb.
Initially, the IRAP therapy successfully blocked the inflammation—keepers noticed that Shanthi was moving about her exhibit more overall, and Zoo veterinarians noted that the inflammatory markers that they evaluated in her blood and joint fluid showed improvement as well.
Prior to Shanthi’s case, joint fluid prostaglandins and serum cytokine and interleukin inflammatory markers had not been previously used to monitor and assess osteoarthritis in elephants at the Smithsonian’s National Zoo or elsewhere.
It can take four-to-eight weeks after administration for staff to see the benefits of the procedure. Then, five-to-seven months after treatment, those benefits would begin to wear off. Animal keepers and Zoo veterinarians closely monitored Shanthi’s behavior, mobility and medical parameters; when they indicated the discomfort had returned, additional rounds of IRAP therapy were administered, roughly every five-to-eight months. To date, she has received 14 treatments—seven in each wrist.
Following Shanthi’s last IRAP procedure Sept. 11, 2018, animal care staff noticed that she was not responding as favorably as she had with previous treatments. Shanthi would shift her weight disproportionately from one front leg to the other while standing, and she would take shorter, stunted steps when she walked. Her reaction to these movements was a sharp one—an obvious sign of discomfort.
Another key indicator that Shanthi was not feeling well was her detachment from social interactions with Ambika and Bozie. Normally, the three elephants stay within close proximity to one another, whether they are exploring their habitat, foraging or going about other activities throughout the day. Whenever they reunited—even after spending just a few minutes apart—the triplet would erupt in a boisterous celebration, greeting one another with a symphony of trumpeting, squeaks, honks and rumbles. Shanthi’s detachment did not occur suddenly; rather, it slowly trended on and off over the course of several months. Her normal level of enthusiasm was not there.
Concerned that Shanthi’s overall demeanor seemed to be “off” and her level of comfort was not where it needed to be, the Zoo’s elephant and veterinary teams discussed alternative treatment options with Dr. Anikis. He recommended a new treatment called Osphos—a medication that helps to minimize bony remodeling, which can lead to bone resorption and the formation of calcium phosphate crystals in bones and joints with osteoarthritis.
Zoo veterinarians administered Osphos intramuscularly—the first application in elephant care—April 10, 2019. In addition, long-acting steroids were administered into Shanthi’s wrist joints to further reduce inflammation and discomfort.
Although it may be several more weeks before the full effects of the steroid and Osphos treatments reach their peak, Shanthi is steadily improving. As part of their daily husbandry routine, elephant keepers use a chart to track Shanthi’s daily activity, movement and appetite, as well as her interactions with keepers and other elephants. In the days following the treatment, staff saw improvement in Shanthi’s range of motion in her left wrist, as well as improved overall movement and advancement of the right foreleg and carpal joints. In addition, Zoo veterinarians monitor Shanthi’s bloodwork parameters on a regular basis to further assess the degree of inflammation, response to therapy and when she may need to have additional treatments.
Over the last month, both keepers and veterinarians have observed that Shanthi’s condition and overall quality of life has been trending in a positive direction. Not only has Shanthi been more cooperative with keepers and more willing to move about her enclosures, but now that the weather is warmer, she has been seen swimming in the outdoor pools, too. Her social patterns are returning to normal, and keepers routinely see and hear Shanthi socialize with Bozie and Ambika throughout the day. These developments are encouraging signs that she is feeling better.
Animal care staff are cautiously optimistic that they will continue to see the benefits of this new treatment as well as future IRAP treatments. By using a variety of novel therapies that target different aspects of Shanthi’s osteoarthritis, staff hope they are able to help minimize her discomfort, inflammation, pain and bony remodeling. In doing so, they can lower the doses of her chronic medications—such as ibuprofen—to minimize their potential side effects.
Shanthi’s condition—though being slowed—is incurable. Her recent positive response to them gives the Zoo’s animal care team hope that her quality of life will continue to rise. For the wider zoo community, Shanthi’s medical journey demonstrates how these innovative treatments have the potential to help other elephants.Read more about Shanthi’s past treatments here.