LAKES -- Public health officials issue warnings this time of year to be wary about the color of the water we enjoy for recreation.
Algae, the microscopic organisms that grow naturally in the ocean and fresh water, are generally harmless.
But one kind, called cyanobacteria or blue-green algae, can produce toxins capable of causing illness in people and animals, including dogs.
People can be exposed in several ways — through contact while wading or playing in the water, swallowing affected water when swimming, or inhaling water droplets during activities like water-skiing.
Read on for details from an Associated Press report.
Exposure can result in a range of symptoms including skin rash, diarrhea, cramps, vomiting, numbness, dizziness and fainting. The state will issue health advisories when blue-green algae blooms are spotted.
Dangerous algae blooms have been on the rise in Oregon in recent years, although health officials aren't sure why. Last year, officials issued 22 advisories in 9 counties.
Still, only a fraction of Oregon's waterways are monitored, so the public might not always get notice of dangerous algae.
"For this reason, people should always be aware of conditions before they go into the water," said Jennifer Ketterman with Oregon's Harmful Algae Bloom Surveillance program. "If it is foamy, scummy and thick like paint and pea-green, blue-green or brownish-red in color, it's best to stay out."
Dogs are also susceptible to toxic algae. In 2009 and 2010 several dogs died after coming in contact with harmful algae in Oregon.
"We want people to be aware so they know to keep their pets out of potentially dangerous water," Ketterman said.
Dogs can be exposed when they drink bloom-infected water or when they lick their fur after swimming in the water.