For a 2-foot-long lizard, the Gila monster has had an outsized impact on modern pharmaceuticals. Gila monsters have natural hormones, called GLP-1 inhibitors, that allow the animals to fast all winter long. Research into those inhibitors helped spawn recent blockbuster GLP-1 medications, like Ozempic, for diabetes and weight loss.
So when a local Gila monster needed help fighting off a nasty gastrointestinal parasite, it only seemed fair that a pharmaceutical expert stepped in to help.
Pebbles the Gila Monster has lived for nearly a decade at the Creature Conservancy, a nonprofit wildlife education organization and rescue-animal refuge just south of Ann Arbor.
In March of 2023, she was diagnosed with cryptosporidium — a highly infectious gastrointestinal parasite that is often a death sentence for Gila monsters.
“But it just went against all what we stood for to euthanize her,” Xavier Edwards, reptile curator and assistant head curator at the Creature Conservancy, told Stateside. “So we isolated her, kept her separate, and really kind of hoped for the best.”
That’s where Tim Cernak came in. Cernak is an associate professor of medicinal chemistry at the University of Michigan. He’s also a pioneer in a field of study that he has coined “conservation chemistry.”
Conservation chemistry, Cernak told Stateside, is a new approach to conservation biology. That field also got its start at U-M in the mid-1980s. Cernak credits conservation biology with the recovery of both the bald eagle and humpback whale populations.
“Both of those species were on the ropes of extinction,” Cernak said.
Likewise, conservation chemistry also looks to protect endangered species. But it does so by taking on threats of disease and invasive species with a distinctly human tool: pharmaceuticals. In other words, prescribing medication to endangered animals.
Much of Cernak’s current research centers on the fungal infection chytridiomycosis, which is a primary driver of population decline in amphibians. Chytridiomycosis was first described in the 1990s, during a precipitous decline in frog populations. Threats to frog species are particularly dangerous, Cernak said, because frogs form a key link in the middle of the food chain, between insects and larger predators.
According to Cernak, that makes chytridiomycosis “the worst pandemic our planet has ever known. It’s the most destructive disease that’s ever been documented.”
Cernak uses artificial intelligence to predict which pre-existing drugs might be effective for use in endangered species.
AI, Cernak said, “is really good at taking lots of data and then pivoting it in a new direction. And so we can take all of this knowledge around medicine for humans and say, ‘Now translate that so that everything is lined up for a frog.’”
This past year, Cernak applied that same AI technique to treat another disease: the cryptosporidium parasite living inside Pebbles the Gila monster.
After hearing about Pebbles’ diagnosis from Steve Marsh, head curator at the Creature Conservancy, Cernak and his team got to work collecting and testing samples from Pebbles.
By December 2024, almost two years after the original diagnosis, Pebbles’ caretakers were desperate to try something. The Gila monster’s weight had dropped dramatically and she was nearing a point of no return. So the Creature Conservancy started her on a drug recommended by Cernak called paromomycin
And it worked.
Within just a few months, Pebbles’ tests came back negative for cryptosporidium — an extremely rare reversal of a disease that, for Gila monsters, is almost always fatal.
Cryptosporidium is unpredictable, which means Pebbles will continue to get tested regularly.
But there are key signs that Pebbles is getting better. She’s much more eager to eat her regular diet of chicken, duck, and quail eggs. And she’s shedding her old skin, which, according to reptile curator Edwards, is another indication that she’s growing again.
Once Pebbles’ vibrant new skin comes in, Edwards said, “she will be even more beautiful than she is right now.”
