Oregon Dog Health Alert - Rivers and Lakes with poisonous algaes and other polutants
Summer water fun can lead to illness and even death
Updated June 17, 2025 (Oregon)
It’s getting warm outside and many George and Friends dogs and their owners are outdoors enthusiasts. We have some of the most beautiful lakes, rivers and ponds. Last year there were a couple of deaths of dogs reported due to toxic algae on the Columbia river. Harmful algae and cyanobacteria (sometimes called blue-green algae) can produce toxins (poisons) that can make people and animals sick and affect the environment. Children and dogs are particularly vulnerable. In Oregon, the Oregon Health Authority (OHA) and the Oregon Department of Environmental Quality (DEQ) are the primary agencies responsible for monitoring and testing water quality in lakes and rivers for toxins, including harmful algal blooms. They collaborate on programs like the Oregon Beach Monitoring Program and address various water quality issues, including toxins from algae blooms and other pollutants.
Not all waterways are monitored for poisonous algae blooms, so be smart and when in doubt… stay out! The latest advisory from the OHA (Oregon Health Authority) warns of potential toxic exposure in the following locations:
Lost Creek Lake in Southern Oregon / Jackson County 6.13.25 PRECAUTIONARY
Prineville Reservoir in Crook County 6.13.25 PRECAUTIONARY
Devil's Lake in Lincoln County 6.13.25 PRECAUTIONARY
Columbia River shoreline at Cottonwood Beach in Washougal, WA 5.28.25
This advisory is for benthic algae mats, which are often attached to the bottom of waterways in mats, blobs or spires, or detached and floating in clumps. They can occur anywhere in a fast or slow-moving water body, do not affect water clarity, and can feel slimy, gelatinous or slippery.
Lake Owyhee (northern portion, starting at Indian Creek Campground extending to the reservoir outflow) in Malheur County 5.23.25 PRECAUTIONARY
Wapato Marsh at Oaks Bottom Wildlife Refuge in Multnomah County 5.1.25
The Oregon Veterinary Association issued a permanent warning for pet owners for South Umpqua River and Lawson Bar. The advisory covers the South Umpqua River from Canyonville downstream to the confluence with the mainstem Umpqua River, and the mainstem Umpqua River downstream past Elkton to Sawyers Rapids. Pools in the bedrock along the rivers edge are known to develop cyanobacteria (blue-green algae) blooms that can be harmful to pets and people if accidental ingestion occurs.
DAN KRAKER, MPR News
DR. JENNIFER L. GRAHAM, U.S. Geological Survey
What is toxic algae?
Algae and cyanobacteria are simple, plant-like organisms that live in the water. Algae and cyanobacteria can rapidly grow out of control, or “bloom,” when water is warm, slow-moving, and full of nutrients. Blooms can occur in fresh water, salt water, and brackish (a mixture of fresh and salt) water around the world. Blooms sometimes look like foam, scum, mats, or paint on the surface of the water. They can even make the water appear different colors, including green, blue, red, brown, or another color. The warm weather and warmer water temperatures can contribute to the increase in toxic blooms so can fertilizer, sewage, or runoff from cities and industrial buildings.
Blooms of algae or cyanobacteria can be harmful to people, animals, or the environment if they
produce toxins (poisons)
become too dense
use up the oxygen in the water or
release harmful gases
Symptoms in dogs
Exposure to toxic blue-green algae can result in:
Weakness or collapse
Nausea, vomiting
Excessive drooling
Abdominal pain
Diarrhea
Difficulty breathing
Shaking, trembling
Tremors, rigidity, paralysis
What to do?
If your dog goes into the water:
Don’t let your pet lick its fur.
Wash your pet with clean water as soon as possible.
If your dog has symptoms such as drooling, weakness, vomiting, staggering and convulsions after being in water, seek immediate veterinary care. Acute, life-threatening symptoms from cyanobacterial toxins often develop rapidly. Death can occur within minutes, hours or a few days after exposure.
How People and Animals Get Sick
When in doubt, keep children and animals out! Cyanobacteria can be deadly for children and animals.
People and animals (including pets, livestock, and wildlife) can get sick when they have contact with water or food that contains certain types of algae, cyanobacteria, or their toxins.
People and animals can get sick if they
swim, wade, or play in or near contaminated water
eat contaminated fish, shellfish or
use contaminated drinking water
Illnesses and symptoms can vary depending on how a person or animal was exposed (came into contact with algae, cyanobacteria, or their toxins), how long they were exposed, which type of toxin was present, and how much toxin was present. Exposure to some algal and cyanobacterial toxins can also harm your liver and kidneys. If you think you may have symptoms caused by harmful algae, cyanobacteria, or their toxins, contact your healthcare provider, veterinarian or Poison Control.
Human symptoms can include
stomach pain, vomiting, or diarrhea
general symptoms, like headache
skin, eye, nose, or throat irritation
neurological symptoms (for example, muscle weakness, dizziness)
Animals are often the first affected, in part because they are more likely to swim in or drink from bodies of water that contain harmful algae or cyanobacteria. See the CDC Animal Safety Alert fact sheet for more tips to protect your pets.
References:
https://www.oregonvma.org/toxic-algae-advisories
https://www.opb.org/article/2025/05/28/toxic-cyanobacteria-algae-health-clark-county-dog-deaths/