A rare disease has been found in a walleye at Lake Pueblo, and Colorado anglers are urged to not eat walleye that is or may be infected.
Myofibrogranuloma, a rare degenerative muscle disease known as “Sandy Flesh disease,” has been confirmed in a single walleye caught last fall at Lake Pueblo State Park, according to a Colorado Parks and Wildlife news release.
Sandy Flesh disease is not believed to be transmittable to humans, but CPW urges people to not consume walleye they suspect is infected. Instead, anglers are asked to report suspect catches and turn in photographs that will be analyzed by staff at the CPW’s Aquatic Animal Health Laboratory.
The fall incident is the first time Sandy Flesh disease has been found in Colorado, according to the CPW. The disease, which has been known to exist for decades, is typically found in the Midwest including North and South Dakota, Minnesota, Wisconsin and Nebraska; it has been spreading west to include Utah, Idaho, Wyoming and now Colorado.
Sandy Flesh usually impacts fish in small numbers, primarily older Walleye. The cause of the disease and means of transmission are unknown. Yellow perch can also be infected, although those cases are in smaller numbers.
“It’s not a shock that it has reached Colorado since it occurs in so many neighboring states, but it is unfortunate,” said Carrie Tucker, CPW aquatic biologist in Pueblo. “We don’t expect it to have a big impact because it typically only shows up in a small number of older walleye.
“But it’s important that walleye anglers be aware and carefully inspect their catch when they are cleaning them. We urge anyone who finds Sandy Flesh in a fish to report it to CPW immediately and provide good, high-resolution photographs.”
Fish with Sandy Flesh look normal on the outside, but the disease can be spotted when a fish is cleaned. Areas of the filet will look semi-translucent, or yellowish brown, with knotted muscle fibers, the release said. The disease may look granular with mineral deposits, or even opaque and it can resemble freezer burn.
Tainted fish should not be discarded back into the water, instead, the diseased fish and entrails should be disposed with household waster or buried.
