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Keep Pets and People Safe around Cyanobacteria

An important message from Lake County’s Public Health Officer, Gary Pace, MD:

Lake County Health Services, Public Health Division
(707) 263-1090

October 3, 2019

Update to Press Release Dated 8/28/19: Keep Pets and People Safe around Cyanobacteria (Blue-Green Algae)

LAKEPORT, CA. In a Press Release issued August 28, 2019, an unfortunate incident was reported of a dog that died suddenly after swimming in the Putah Creek area.  Although no prior cyanobacteria-related animal deaths had been confirmed in this area, local water and health officials were concerned cyanobacteria may be the cause.

An investigation was launched, which included testing water at the incident site, water as far as a mile downstream, and biological samples from the deceased animal.  

Water samples from the incident area were collected and delivered to the Big Valley Band of Pomo Indians for cyanobacteria identification, preliminary testing and toxin analysis.

With the gracious permission of the family, the body of the dog was sent to the California Animal Health and Food Safety Laboratory at UC Davis for testing of the stomach contents and some body tissue, and complex tests were performed looking for anatoxin and microcystin (specific cyanobacteria toxins).  Testing included Mass Spectrometry.

The California Office of Environmental Health Hazard Assessment (OEHHA) performed their own evaluation of the incident, as well.

Because this dog’s symptoms could have been caused by a toxin from algae, local and state groups have helped in evaluating the cause of the animal’s death and level of concern for that location.  The above referenced testing did not detect any of the common types of cyanobacteria toxins in the body of water where the incident reportedly occurred or in the animal tissues. However, although no evidence of toxins was found, testing did not conclusively rule out an algae-related cause.  The results are inconclusive regarding cyanotoxin as the cause of this dog’s death.

Accumulations of cyanobacteria are a common and familiar sight in all freshwater lakes, ponds, creeks and streams. Most frequently visible as green, soup-like water, oily-appearing surface scum or foamy mats, blue-green algae (cyanobacteria) tends to flourish or collect in sunny areas where water is shallow and undisturbed, or in locations where wind and currents cause surface blooms to collect.

Pets, such as dogs, are particularly at risk.  Because they are not deterred by the disagreeable odors of decaying algal mats, they are prone to swallowing water while swimming, and they can also ingest cyanobacteria while self-cleaning their coat following contact with the water.  Contact with visible algal blooms should be avoided.

We appreciate the cooperation and efforts of all parties involved.  Certainly, we also want to remind the public if your animal becomes sick or dies suddenly after recreating in any body of water, please call and/or take the animal to a veterinarian and call your local Health Department.

In Lake County, report such incidents to Lake County Health Services, Public Health Division, at (707) 263-1090.

For more information, please visit:
For current cyanotoxin lab results:

California Harmful Algal Blooms Portal:

Domestic Animals and HABs:

County of Lake Cyanobacteria Webpage:



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