CU Cancer Center consults on king cobra conundrum


Denver Zoo team biopsies a lesion on a king cobra. The results show the exotic animal has a rare form of cancer.

Denver Zoo team biopsies a skin lesion on a king cobra. The results show the exotic animal has a rare form of cancer.

University of Colorado Cancer Center worked with Denver Zoo in an unusual collaboration. Treating a king cobra with cancer is a challenge and as Denver Zoo veterinarian Betsy Stringer learned, the process is associated with some obstacles, but they are not insurmountable.

A keeper at the zoo, Tim Trout, noticed that a king cobra had lost some weight and had lesions on his skin. A biopsy, blood work and x-rays, all taken during a stressful medical procedure with the 12½ -foot venomous snake, revealed it had cutaneous lymphoma, a rare cancer that affects the skin.

So now what? That’s where CU Cancer Center member Douglas Thamm, VMD, DACVIM (oncology), enters the story. He is the Barbara Cox Anthony Professor of Oncology at the Flint Animal Cancer Center at Colorado State University. CSU is part of the CU Cancer Center consortium of research institutions.

Thamm is instrumental in animal clinical trials at CSU and has assisted in advancing therapies available to dogs and cats with lymphoma. Often advancing cancer treatment in companion animals can inform the way people with cancer are treated. Thamm acknowledges the challenges in treating the cobra but also notes a couple strokes of good luck.

Douglas H. Thamm, VMD, DACVIM, Barbara Cox Anthony Professor of Oncology, CU Cancer Center Investigator

Douglas H. Thamm, VMD, DACVIM, Barbara Cox Anthony Professor of Oncology, CU Cancer Center Investigator

“This is obviously an unusual situation,” says Thamm. “Any treatment we recommended for this exotic animal could not involve intravenous access. This animal is very, very, very hard to handle. The only way to administer some chemotherapy drugs would be to knock him out completely.”

The good news for veterinarians is there is a medication called lomustine (CCNU) used in dogs and cats with cutaneous lymphoma that comes in tablet form. The pill lasts approximately three weeks. The cobra just so happens to eat about every two or three weeks so the pill goes in the cobra’s food. If that makes you squeamish, do NOT click here to read The Denver Post article about the snake and administering chemo.

“This is a go to treatment for cutaneous lymphoma in companion animals,” says Thamm. “It made sense to try this medication with this exotic animal.  We believe we treated him appropriately but assessing the outcome will also be a challenge.”

Thamm notes that Denver Zoo’s team of vets is monitoring the snake’s progress and he is optimistic because the snake does not appear to be losing more weight, and chemo did not cause him to lose his appetite.

“I am gratified to work with the team at Denver Zoo,” he says. “This was a bit like the Wild West. Let’s try what we know from treating other critters, because we know what happens if we don’t try anything.”

This king cobra will help build a framework for treating cancer in exotic animals by adding to a very limited body of knowledge. Denver Zoo staff members’ goal is for the cobra to enter remission, but even if not, hope they can at least improve its quality of life and maybe extend that life.

“We definitely appreciated Dr. Thamm’s help. From our largest elephant, to our smallest snakes, every animal at Denver Zoo matters,” says Stringer. “If there was anything we could do to help this snake, we had to find it and try it.”

“It may be too early to talk about the outcome,” says Thamm. “But he seems to be doing well and this treatment didn’t hurt him.”



About the author: Erika Matich

Erika Matich is the communications manager for the University of Colorado Cancer Center. Contact her at Erika.Matich [at]

Comments are closed.