DOUGLAS COUNTY, Ore. -- Drowning isn't the only threat that water poses during the warm summer months.
Water from the South Umpqua River in the Myrtle Creek area was tested last week because a pet dog died after playing in the water.
The testing revealed blue-green algae, which can produce toxins harmful to people and pets.
Officials say that test results from the deceased dog aren't in yet, but toxic levels of algae could be to blame.
The South Umpqua River near Myrtle Creek now has a health advisory, urging everyone to be careful.
People are asked not to drink or even touch the water, and to keep their pets out of it.
Generally, officials wait until someone reports the death of an animal to test for toxic algae levels, and they say they can't afford to do it any other way. "Because there's so many rivers and so many streams in the state, there would be no possible way to even begin to have the staff to monitor that," said Caroline Gross-Regan, an environmental health specialist with the county.
Blue-green algae can cause numbness, difficulty breathing and heart problems. In pets, it can cause lethargy and loss of appetite.
Children and animals are especially vulnerable to the toxin.
A Yoncalla man says that his dog got sick and eventually died after playing in the Umpqua River near Elkton, but he declined an autopsy on his pet.
Gross-Regan said she was not aware of an algae investigation in the area.
Caroline says that the best way to keep your pets safe is to keep them away from still waters. "I would really look for areas where water can pool and stagnate, and even if I didn't see scum, I would avoid any of those areas where the water just sits," she said. "Definitely keep them away if you do see it."
Gross-Regan points out that the government can't afford to test every lake, river and stream in Oregon.
Even if there isn't an advisory, a waterway could still be dangerous, and she warns people to be on the lookout for algae blooms.
Besides the local rivers, Diamond Lake is also under an algae advisory.