“They did reach out to us and asked what kind of sensors might be available. We connected them to Dexcom,” a CGM company that’s based in San Diego, Dr. Tsimikas said. “We knew the newest one was coming along and suggested they place that on him as a starting point.”
On June 1, a zoo team attached a Dexcom G6 Continuous Glucose Monitoring System to the koala’s side.
“He’s doing very well. He tolerates the CGM superbly,” Dr. Singleton said. And Quincy doesn’t react when sensors are applied, she said, although it helps that he gets to enjoy a eucalyptus smoothie during the procedure. “Put that in a big syringe, and he’ll volunteer for most anything,” she said.
Obesity can trigger diabetes in mammals other than humans. Could eucalyptus overindulgence explain Quincy’s case of diabetes? Nope.
According to Dr. Tsimikas, the ingredients of the eucalyptus smoothie are just pureed eucalyptus leaves that “go down fast and easy.” These naturally have a nice mix of carbohydrates, fat, and protein to better manage the koala’s sugars and other nutritional needs. If he is dropping his blood sugar values fast, there is another dextrose drink they give him in small amounts, which contains 5-10 g carbohydrates. This is enough to help bring his glucose values back up. It is similar to the treatment recommendations provided to humans with diabetes where they are told to take 15 g of carbohydrates such as honey, hard candies, or juice to prevent a severe hypoglycemic episode.
Dr. Singleton noted that Quincy appears to have the koala equivalent is type 1 diabetes mellitus (T1DM).
Dr. Tsimikas noted “We are not finding the typical antibodies that we find in human T1DM. Quincy is showing low insulin levels, which is why it more closely resembles T1DM. We will be doing further analysis and comparisons with nondiabetic koalas in the future to see if it can be better differentiated.
While he appears to have type 1 diabetes, it’s not clear why he developed it, Dr. Singleton said.
While Quincy is only 3 years old, he’s a full-fledged adult in koala terms. Koalas typically live up to their mid-teens, she said.
This speechless patient still manages to communicate
The San Diego Zoo’s veterinary staff is monitoring Quincy and trying to understand how his glucose levels and daily insulin shots affect him. His tiny size has ruled out use of an insulin pump: Although the insulin pumps have been getting smaller and lighter, they are still too large to attach to our tiny friend. Especially since he would need both the CGM device and the pump, there is not a lot of surface area on his body for attachment of all the devices, according to Dr. Tsimikas.
Dr. Athena Philis-Tsimikas
Since Quincy is so tiny, insulin doses must be minuscule to avoid sending him into hypoglycemia, Dr. Tsimikas said. She said the koala’s medical team is planning to try using a NovoPen Echo injector with a half-unit of insulin.
Dr. Singleton noted that for now, “he’s maintaining his body weight, and he has days when he feels spunky. Sometimes, when he knows it’s breakfast time, and he hears his caretakers coming up the doorway with his breakfast, he’ll be very active on his perch.”
But he has sluggish days, too, when he’ll try to sleep in. Dr. Singleton keeps an eye out for grogginess and signs of weakness and hypoglycemia or hyperglycemia like “a little wobble in his step.”
“The biggest thing I’ve learned from Quincy is the value of his particular nonverbal cues,” she said. “I’m starting to understand when he feels like his sugars are a little high or a little low. I imagine that doctors and parents have the same challenges with little patients, along with figuring out how you communicate that this is supposed to help them.”
Dr. Tsimikas agreed, noting that she sees similarities between Quincy and patients who are hospitalized and can’t easily communicate. Now, “we can track the folks who are on the CGM and intervene earlier than before,” said Dr. Tsimikas, who’s part of a clinical trial team testing CGM devices in two hospitals. “It’s almost like having another vital sign.
“It is only when we have all the data on all the other factors that can influence blood sugar, such as eating patterns, insulin dose and timing, and activity level that we can more accurately adjust the medical interventions.” This requires collaboration between all the groups involved in Quincy’s care. In koalas, the collaboration is with the veterinarian, koala zookeepers, dietitian, and the technology monitoring team. Whereas, for humans, we need parents, care providers, diabetes educators, dietitians, and physicians.
It’s not clear if Quincy will need his CGM for the rest of his life. If he’s stable on a specific insulin dose, Dr. Tsimikas said, he may not need it. But it sounds like eucalyptus smoothies will always be a vital part of his regimen.
In the name of thoroughness, take note that Quincy is not the first diabetic zoo animal whose care involved physicians from Scripps. “We have had several other consultations for animals with diabetes. Nearly 25 years ago, a roller-skating chimpanzee with diabetes was brought to the Scripps Whittier Institute labs for evaluation and treatment recommendations. A few years later, one of our medical directors, Alberto Hayek, MD, advised on the care of Lune, a diabetic baboon at the San Diego Zoo, for insulin management. This time we are making house calls to the zoo to treat Quincy in his home environment. Each animal experience offers opportunities to expand our knowledge about diabetes care and exchange approaches that we might not otherwise be aware of. This has been fun and rewarding. I am looking forward to seeing further outcomes from our interactions with Quincy,” according to Dr. Tsimikas.
Dr. Tsimikas reports that her center conducts research with Dexcom and Novo Nordisk. Dr. Singleton reports no relevant disclosures.