06/03/2026
Oregon Health Authority is reminding the public that we are entering the season for harmful algae blooms. Not all Oregon waterways are monitored for cyanobacteria, so it's important to know what to watch for. A harmful algal bloom can look foamy, scummy, thick like paint, and pea-green or blue-green in color. It can look like a thick green or brownish-red mat, or bright green clumps suspended in the water. If you find thick, brightly colored foam, scum or mats in a lake, pond, river or stream—especially in shallow, marshy areas where cyanobacteria blooms can form—don’t let your pet drink or swim in the water.
Symptoms in Dogs
Exposure to a harmful algae bloom can result in:
* Weakness or collapse
* Nausea, vomiting
* Excessive drooling
* Weakness, fatigue, stumbling
* Abdominal pain
* Diarrhea
* Difficulty breathing
* Shaking, trembling
* Seizure like activity—tremors, rigidity, paralysis
* Liver failure
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 cyanobacteria toxins often develop rapidly. Death can occur within minutes to hours after exposure.
Current advisories:
* Lost Creek Lake in Jackson County (Precautionary)
* Agency Lake in Klamath County (Precautionary)
* Upper Klamath Lake in Klamath County (Precautionary)
* Haystack Reservoir in Jefferson County (Precautionary)
* Ochoco Reservoir in Crook County (Precautionary)
* Willow Creek Reservoir in Morrow County (Precautionary)
* McKay Reservoir in Umatilla County (Precautionary)
Precautionary Status: A bloom has been sighted and water sampling is unavailable within 1 business day due to limited resources. Oregon Health Authority will issue pre-emptive public warnings following reports of dog illnesses or deaths possibly resulting from cyanotoxin exposure.
* South Umpqua River: 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. (PERMANENT ADVISORY)
We post algae advisories on our Web site at: https://www.oregonvma.org/toxic-algae-advisories
