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Keep Pets and People Safe Around Blue-Green Algae

LAKEPORT, CA.  Accumulations of blue-green algae are a common and familiar sight in freshwater lakes, ponds and streams throughout the country, including Clear Lake. Most frequently visible as green, soup-like water, oily-appearing surface scum or foamy mats, cyanobacteria tend 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. Some blue-green algae produce toxins that can pose a range of health risks to people and animals when they are exposed to them in large enough quantities.
Water monitoring for cyanotoxins is regularly done by the Big Valley Band of Pomo Indians and Elem Indian Colony.  This is a valuable service, and helps facilitate safe lake use. The most recent water testing results of Clearlake of 22 sites throughout the lake on 8/20/19 were all below the Caution level.
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 ingest cyanobacteria while self-cleaning their coat following contact with the lake. While a pet illness from cyanotoxins has not been confirmed, the recent death of a dog earlier this week has prompted local officials to remind residents and visitors to take precautions for the safe enjoyment of Clear Lake and other nearby water bodies.

A dog passed away earlier this week following a brief severe illness that began immediately after swimming in the Putah Creek area. The cause of the illness is still being evaluated. Water samples from the swim area were collected and delivered to Big Valley Band of Pomo Indians for cyanobacteria identification, preliminary testing and sending off for toxin analysis.

Lake County Public Health has arranged for specialized testing at the California Animal Health and Food Safety Laboratory in Davis in order to determine if the illness was caused by cyanotoxins.

Symptoms in the pet are consistent with possible cyanotoxin exposure, including difficulty breathing, unresponsiveness, and tongue and gums turning a bluish color. Humans recreating nearby have not reported illness.
There was a laboratory documented case of a cyanotoxin-related death of a dog in Lake County in 2013, and this case is an indication that caution might be needed even when algal accumulations do not appear as severe as in previous years. County officials urge the community to use appropriate precautions while this scientific testing is completed to determine if any potential health risks associated with cyanobacteria exist.
Regardless of any eventual findings in this case, Scott De Leon, Interim Director of Lake County Water Resources and Erin Gustafson, MD, MPH, Lake County Public Health Officer, urge the public to observe important safeguards to avoid harmful effects of cyanobacteria. These include:
• Avoid contact with water in areas with surface foam, scum, or a pea soup appearance. This is particularly important for small children and pets.
• Avoid generating aerosols (water skiing, jet skiing, etc.) in areas of the lake where there are signs of blue-green algae
• After swimming, towel off properly. Even better, shower with fresh water. After pets swim, rinse with fresh water and towel them dry to prevent them from ingesting the blue-green algae while self-cleaning.
• Never drink untreated lake or other surface water. Boiling water does not guarantee that it is safe to drink.
• If unexplained illness develops following direct exposure to water in a lake, pond, or stream, see a doctor (or bring your pet to a veterinarian) promptly and be sure to mention the exposure that occurred.
For more information and resources, visit the County’s cyanobacteria pages: Action levels for acute exposure for dogs for cyanotoxins
For current cyanotoxin lab results, please visit the Big Valley Band of Pomo Indians cyanotoxin monitoring website:


Water Faucet
Urgent Health Advisory

Effective immediately, people on private water systems whose tap water comes from their own private intake into the lake, in the Oaks Arm and Lower Arm of Clear Lake should not drink the water.

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