TUESDAY, September 1, 2026|
Photo – Invasive goldfish – Courtesy Wyoming Game and Fish
The Wyoming Game and Fish Department is asking the public not to release pets into the wild.
Wyoming Game and Fish has received numerous reports of invasive goldfish in the state’s waterways. Casper Region Public Information Specialist Janet Milek said releasing unwanted pet goldfish may seem harmless, but it can have significant, unintended effects on the ecosystem.
While the fish itself might not pose a large threat, Milek said it may carry diseases or also introduce other aquatic invasive species such as zebra mussels. In addition, she said goldfish can crowd out native species, reducing the supply of sport fish.
Milek added that the state’s harsh winters are likely to kill most pets. The public information specialist urged people to consider the consequences of releasing pets into the wild before acting.
In 2022, a similar situation occurred at Saratoga Lake when an unknown person introduced invasive yellow perch into the water. To keep the fish from spreading into the North Platte River system, Game and Fish used a toxin called rotenone to kill all aquatic life in the lake. The following spring, the agency restocked Saratoga Lake with thousands of trout.
Game and Fish Casper Region Public Information Specialist Janet Milek said residents have found truly exotic species, not just goldfish or yellow perch, in her area’s waterways.
Milek clarified that none of those animals have been discovered in the North Platte River.
Instead of releasing unwanted pets into the wild, Milek recommended contacting the United States Fish and Wildlife Service’s Don’t Let It Loose campaign. The program offers information about responsible pet surrender and provides a database of rehoming resources across the country and parts of Canada.
Public Information Specialist Milek said Game and Fish also uses the Don’t Let It Loose campaign as part of its aquatic invasive species program.
In addition to the damage the animals can cause to the environment, releasing pets is a crime that carries some of the highest penalties for wildlife violations. People caught releasing non‑native species may face fines of up to $10,000 and the loss of their hunting and fishing privileges.
The Wyoming Game and Fish Department is asking the public to follow C.A.R.E. guidelines. First, contact the place where you purchased the pet to see if they will take it back. Next, act responsibly by never letting animals or plants loose into the wild. Research other places that may be able to provide a new home for your pet. Pet stores, zoos, aquariums, science centers, animal shelters, and humane societies all may be able to help. And finally, as a last resort, euthanize the animal in a humane way. Wyoming Game and Fish states on its website that this option is far more humane than letting the animal starve to death in the wild or destroy the homes of native animals. Game and Fish also advises freezing unwanted plants before throwing them in the trash.
For more information about rehoming an unwanted pet, visit www.dontletitloose.com or call your local Wyoming Game and Fish office.
