Toxic Blue-Green Algae Forces Trail Event Cancellation

Toxic Blue-Green Algae Forces Trail Event Cancellation

A competitive trail ride in Kansas was canceled after blue-green algae in a reservoir scheduled to be used for cooling the horses in warm temperatures.

Photo: Anne M. Eberhardt/The Horse

A North American Trail Ride Conference trail ride in Kansas scheduled for July 30-31 was canceled due to the presence of blue-green algae (BGA) in Big Hill Reservoir near Cherryvale. Ride organizers cited the health risks for horses and humans from BGA as the reason for the cancellation.

"We planned to use the many lake access points to cool the horses during a high temperature competition," said ride manager Priscilla Lindsey. "People were eager to compete, even with the heat, but we felt we had to put the welfare of both horses and riders first."

A photosynthetic bacterium called cyanobacterium that utilizes sunlight for energy, BGA grows rapidly on farm runoff nutrients such as nitrogen and phosphorus. Hot, dry conditions, stagnant water, and long summer daylight hours encourage the production of these harmful algal blooms.

Clinical signs of blue-green algae toxicity include photosensitivity, neurologic problems, bloody diarrhea, labored breathing, liver damage, and convulsions, although these signs might not be noticed before death occurs. Animals that survive might experience lasting problems including failure to thrive or photosensitization affecting white muzzle or other sensitive skin areas.

The Kansas Department of Health and Environment has received reports of at least two cases of human illness and nationally, the toxins have caused several deaths in dogs. Kansas Public Health veterinarian Ingrid Garrison, DVM, MPH, Dipl. ACVPM, and Deon van de Merwe, MSc, PhD, BVSc, head of toxicology at the Kansas State University Veterinary Diagnostic Laboratory, have sent out a joint request to all Kansas veterinarians asking that they report any suspected illness in animals due to BGA.

Garrison noted, "BGA is an emerging public health issue and often livestock species serve as sentinels for human illness."

Equestrians should heed posted blue-green algae advisory or warning signs on trails near lakes. Although the harmful algal blooms are often visible and appear as blue-green scum, they can also grow in a variety of colors and appear similar to an oil slick.

About the Author

Marsha Hayes

Marsha Hayes has been covering endurance, trail, and other equine topics since 2005. She believes every horse has a story.

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