A newly discovered fungus is thought to be causing a shell disease that is harming freshwater turtles, including western pond turtles in the Columbia River Gorge.
“It’s always exciting to identify a new organism,” said Karen Terio, chief of the University of Illinois Zoological Pathology Program. “Once you are able to culture and identify, then you can see what drugs and treatments it might be susceptible to.”
The slow-developing disease causes lesions on a turtle’s shell, softening the protective surface and eventually softening bone and affecting tissue.
The Washington Department of Fish and Wildlife removed 13 turtles with suspected cases of shell disease from an area in Klickitat County and delivered them to the Oregon Zoo in July. All but two of them tested positive for the fungus.
Jason Wettstein, community relations manager at the state Department of Fish and Wildlife, said research on shell disease has been a group effort. It has benefited from financial support provided by The Morris Animal Foundation to the University of Illinois.
Kelly Flaminio, a veterinarian at the Oregon Zoo, said that researchers are testing different antifungals in hopes of finding a way to treat the turtles without removing them from the wild.
“I think probably not messing with them is better for them than having to handle them every day,” Flaminio said.
One approach being explored is placing time-release implants that would allow for a slow release of antifungal agents over time.
“It’s never been done in turtles,” she said.
Currently treating an infected turtle means 2 1/2 hours of surgery followed by 24 hours in a recovery tank before being returned to temporary habitat with the other turtles.
Flaminio said researchers hope the implant can eventually be administered in the field with no need for surgery. Turtles that have too much damage to their shell will still need to be cared for in captivity.
Terio said it is common for reptiles to suffer from some form of infection on their skin or scales, but shell disease is a new discovery in turtles.
The university identified the shell disease in 2011, and the Washington Department of Fish and Wildlife started seeing signs of shell disease the next year. Both entities referenced their archives, and through photos and tissue samples confirmed that the discovery is new but the disease is not.
According to a July 15 press release, the Morris Animal Foundation study identified a new fungus linked to freshwater turtle shell disease. The newly discovered fungus belongs to a group of fungi found to cause infection in reptiles. This fungus is distinctly different but causes a similar disease.
“What we do know is that the fungus is very highly associated with the shell lesions,” Terio said.
In order to prove that the fungus is the cause of shell disease, researchers will have to go through a process that will require them to infect healthy turtles. “We are testing cures as well,” Terio said. She said that having a cure before infecting healthy turtles is an important step in the research.