Catalano's study goals were twofold: To evaluate whether goldfish could maintain water quality and to determine how frequently horse people use this method. | Photo: Courtesy Devan Catalano

Anecdotal evidence suggests placing common goldfish in horses’ water tanks will help keep the troughs clean and free of algae. But Devan Catalano, a PhD in animal science at the University of Minnesota, in Minneapolis, recently determined that’s not necessarily the case, also finding that certain water troughs are better suited for staying clean than others.

Catalano presented her study results at the 2019 Equine Science Society Symposium, held June 3-6 in Asheville, North Carolina.

“Algae is a growing problem” during warm months, she said. “Small quantities can turn water green and affect horses’ intake, while large quantities can be toxic. It’s hard to control, and cleaning is time- and labor-intensive