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December 22, 2023

Toxic algae in King County lakes – keep dogs out of water; follow posted signs before swimming

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Summary

Due to toxic algae blooms, Public Health – Seattle & King County recommends that you keep your pets away from the water in King County lakes where algae is visible. People should follow posted guidance at parks and beaches. Avoid going into the water at any lake where you can see algae, or where there is an advisory posted.

Due to potentially-toxic algae blooms, Public Health – Seattle & King County recommends that you keep your pets away from the water in King County lakes with visible algae blooms. Don’t allow pets to drink the water or get it on their fur.

People should follow posted guidance at parks and beaches. Avoid going into the water at any lake where you can see algae, or where there is an advisory posted. Remember – when in doubt, stay out.

Background

We have recently detected toxic algae in Lake Washington, Green Lake, and Lake Wilderness, and it may be impacting other lakes, ponds, and streams in King County. At this time, the levels detected could harm pets, and some algae blooms may pose a threat to human health. Algae blooms and associated toxin levels can shift quickly. Given this, out of an abundance of caution, Public Health advises that pets not enter the water in King County lakes where algae is visible, and that people follow all posted signage before entering lake water.

Keep pets safe

Working with partners, we are posting signs at lake beaches warning people to be aware and keep their pets out of the water if algae is present. If your pet goes in or near water where an algae bloom is present, do not let them lick their fur and immediately rinse them with tap water. Don’t forget to rinse your hands and any exposed skin after rinsing your pet.

Toxic algae can produce toxins that can make people and pets sick, and even be fatal for pets. It’s possible for toxins to be present even if you can’t see algae in the water. If your pet goes in or near the water at a King County lake, we recommend monitoring them for these symptoms: low energy, not eating, vomiting, diarrhea, difficulty breathing, or seizures. Symptoms will typically occur within minutes to hours after exposure. If your pet becomes ill, call your veterinarian immediately.

New Year's Day Polar Bear Plunges

We are working with the organizers of several New Year’s Day Polar Bear Plunges around the region. For anyone planning a plunge, we recommend checking with event organizers or city parks departments for the latest information.

More information

We are continuing to monitor this situation and will provide updates on our Swim safety webpage when we have more information. You can read more about toxic algae on the Washington State Department of Health’s algae webpage.

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