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The Oregon Health Authority maintains a list and map of bodies of water tested for cyanobacterial blooms. For more information, visit or call the toll-free information line at 877-290-6767. People or pets sickened by the cyanobacterial bloom can call 971-673-0440 for medical assistance.

Look before you leap. That is the advice given by the Oregon Health Authority to boaters, swimmers and other lake users planning to dive into Lake Billy Chinook this summer.

The health authority issued a seasonal health advisory that cyanobacterial algal blooms, harmful to both humans and pets, may develop in the lake this year. State health officials will keep the advisory in place through the summer in order to eliminate costs associated with repeated notifications.

“There have been no reports at this time of cyanobacterial blooms on Lake Billy Chinook,” according to health authority spokesman Jonathan Modie.

“The advisory issued is a ‘precautionary’ advisory for the lake that will stay in effect from June through September,” Modie continued.

The health authority initially stated Tuesday that the advisory would remain until Nov. 1, but revised that to September on Wednesday.

Due to a lack of dedicated funds for cyanotoxin testing at the county or the Oregon Parks Department, and the expensive cost of toxin testing, it is difficult to get consistent toxin data from all areas of the lake where people can recreate and where blooms may develop, said Modie.

“For these reasons, a seasonal advisory, with warning about the recurring risk of cyanobacterial blooms at the lake, is more protective of public health because people can take the appropriate precautions to eliminate or reduce a potential exposure by looking out for anything in the water that resembles a cyanobacterial bloom,” Modie said.

Exposure to cyanotoxins can cause symptoms similar to what one might encounter during a bout of food poisoning. Stomach cramping, nausea and vomiting are common symptoms. In more serious cases, affected individuals may suffer from numbness, tingling, dizziness and shortness of breath that could require medical attention, according to a health authority statement.

While the toxins are most dangerous when ingested, people with skin sensitivities may also experience a puffy, red rash in the affected area.

When a cyanobacterial bloom occurs, lake users are advised to avoid swimming, water skiing, wakeboarding, tubing or other high speed activities that can send a person hurtling into the water.

Non-water related activities — camping, hiking, biking, picnicking and bird-watching — can be enjoyed with little concern for exposure to cyanotoxins, the health authority said. Some water activities can also be enjoyed safely, such as canoing, fishing and boating, as long as boat speeds are low enough to avoid creating a water spray that can be inhaled.

Visitors to lakes are asked to educate themselves on the warning signs of cyanobacterial bloom.

“The public is advised to stay out of water in any area that has indications of a bloom such as water that looks foamy, scummy, thick like paint, pea-green, blue-green or brownish red in color, a thick mat is present, or when bright green cells can be seen suspended in the water column, making the water a brighter shade of green,” Modie said.

The health authority also warns pet owners to be vigilant when visiting Lake Billy Chinook due to “many reports” of dog illnesses and deaths from exposure to bloom-affected water.

Exposure can occur when dogs lick cyanobacteria off rocks and off their fur, eat the scum or drink affected water, according to the health authority. Twitching, drooling, an inability to stand or walk, convulsions or paralysis are symptoms and should be immediately treated by a vet.

The toxins cannot be removed by boiling, filtering or treating water with camping-style filters, so drinking water affected by a cyanobacterial bloom is not advised under any circumstances according to the health authority.

While fishing is permitted in affected areas, any fish should have its fat, skin and organs removed before cooking, the health authority said.

Cyanobacterial blooms are not limited to Lake Billy Chinook. The blooms can occur anywhere in Oregon, but only a fraction of the many lakes and waterways in the state are tested.

Deschutes County has not experienced any known or recent problems with cyanobacterial algal blooms, according to Dr. George Conway, director of the Deschutes County Health Services Department.

— Reporter: 541-617-7818,