Dog dies an hour after swimming in a river at Zion National Park in Utah, rangers say

A dog swam in a river at a Utah national park and died an hour later, the National Park Service said.

On July 4, the Utah Department of Environmental Quality’s Division of Water Quality and the National Park Service were told that a dog died an hour after swimming in the North Fork of the Virgin River of Zion National Park.

“The dog was playing in the river and at one point was ‘snapping’ at algae growing on the rocks,” NPS said in a news release. “Prior to its death, the dog exhibited symptoms consistent with possible exposure to cyanobacteria toxins — those produced by harmful algal blooms. The dog could not walk, was in pain, and was having seizures.”

Anatoxin-a, a nervous system cyanotoxin, and harmful cyanobacteria were found in the water last week in amounts greater than 55 micrograms per liter in some samples, NPS said. The health threshold is 15 micrograms per liter.

“Cyanobacteria are a natural part of aquatic environments,” park officials said. “Some cyanobacteria may produce dangerous liver and nervous system toxins; when in abundance, toxin concentrations can elevate to levels that affect the health of organisms exposed to them, including people, pets, and livestock.”

Visitors at Zion National Park should not swim in the area or drink the water, NPS said. Animals should stay away from the water as well, and fishermen should clean fish well and discard the guts, officials said.

Utah Division of Drinking Water is also verifying drinking water that originates from the river is free of cyanotoxins, NPS said.

“Currently Washington County Water Conservancy District, Zion National Park, and the Towns of Virgin and Rockville are not using the North Fork of the Virgin River as a drinking water source,” NPS said. “To date, tests of Springdale drinking water and agricultural water have not detected the presence of cyanotoxins. Advanced water treatment technologies can remove cyanotoxins.”

Zion National Park is one of the most popular parks in the country. In 2019, nearly 4.5 million people visited the Utah park, according to data from the National Park Service.

This story was originally published July 16, 2020 at 3:20 PM with the headline "Dog dies an hour after swimming in a river at Zion National Park in Utah, rangers say."