Pittsburgh Zoo officials keep close eye on lemur's cancer

Keepers and veterinary staff at the Pittsburgh Zoo & PPG Aquarium are hoping for the best but preparing for any care necessary as they await results on a ringtail lemur’s cancer status.

Caera, a 14-year-old ringtail lemur, showed no signs of distress in the fall, when one of her keepers noticed distention near her left breast. A round of antibiotics resolved the issue until about two months later, when the distention returned, said Dr. Ginger Sturgeon, director of animal health at the Pittsburgh Zoo.

“This is not something we normally see with ringtail lemurs,” she said. “Also, the other side of her mammary gland was completely normal.”

Further exams showed a mass that, after further testing, was found to be carcinoma — a type of cancer that starts in the cells of skin or tissue lining other organs.

Cancer in general — but particularly breast cancer — is extremely rare in ringtail lemurs, Sturgeon said, and she was able to find just two cases in academic literature.

Sturgeon performed a lumpectomy to remove the mass, and she said they’re now waiting for results as to what type of cancer it is.

“So, we know it’s a carcinoma, and it’s going to be some type of mammary gland carcinoma,” Sturgeon said. “But we need to really know what exact type so we can better estimate how this cancer is going to react and if we need to get more aggressive — as in, do a total mastectomy, or do some radiation therapy or do some chemotherapy. All the different types of tumors react a little bit differently.”

The hope, however, is that the surgery removed all of the cancer.

In the meantime, Caera is back with her two grown children, Bridget and Murphy, her mate, Sam, and an unrelated lemur the staff call Auntie Marnie.

Assistant Curator of Mammals Karen Vacco said the zoo’s lemur exhibit is unique in that it is one of the few primate exhibits that zookeepers will actually go in and interact with the animals.

“We don’t push the limits, so they take food from us. We don’t go at them, so they come to us,” she said. “(Caera) tends to be one of the more laid-back, timid ones.”

She said lemurs live in female-led groups, and Caera is generally the leader, which is likely why she hangs back — to keep an eye on things.

The close bond between keepers and the animals is one of the reasons they were able to catch Caera’s cancer early, Sturgeon said.

“So much of what we do comes down to the keepers’ close working relationship with these animals,” she said, “and being able to spot anything out of the norm and notifying us immediately.”