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  • Writer's pictureMatt Erlenbsch

Algae and Your Dog

Updated: Jun 22, 2023

by Liz Stinson.

Protect your dog from harmful algae blooms! With algae being commonly visible in our local waterways here are tips to help you and your dog hike, swim, and hydrate safely.

This guide is an excellent resource to make sense of what we may see out there:

Dogs (and children) are considerably more vulnerable to the dangers of harmful algae blooms due to their smaller size and likelihood to drink water while swimming or hiking, and sadly, the risks in swallowing toxic water can be fatal. The good news is there are ways to identify and avoid harmful waterways to help you and your canine recreate safely in the Sierras.

What are harmful algae blooms?

Algae are plant organisms that naturally live in salt and fresh waterways, ranging in size from microscopic to large colonies of seaweed. While algae may provide important nutrients to aquatic organisms, blooms become harmful when they grow out of control, posing a threat to the health of wildlife, people, and marine ecosystems. Harmful algae blooms in the greater Tahoe basin vary in growth and toxicity levels, and may be found in lakes, reservoirs, streams, rivers, and standing or stagnant water.

Reduced snowpack, increased temperatures, and urban runoff are contributing factors to harmful algae blooms in the Sierras.

How do you identify harmful algae blooms when hiking with your dog?

Although there is no full-proof way to identify harmful algae blooms just by looking at them, there are some tell-tale signs to keep your and your pooch safe. First and foremost, check for any posted signage near the water source indicating it’s unsafe to swim in. If nothing is posted, examine the surface of the water for any discoloration, odors, or flies. If the water appears clear on the surface, check the rocks and shoreline for algae growth. If the rocks are covered in green slime, it’s best to avoid this water source with your dog. Lastly, as a general rule of thumb, avoid all stagnant water such as puddles that have no movement or flow.

What should you do if your dog drinks toxic water on the trail?

If you’ve determined a water source to have harmful algae blooms, the best way to avoid it is to keep your dog from swimming or bathing in the water. However, that’s not always preventable, so in the event your dog has taken a dip or drink from a seemingly unhealthy water source, it’s best to monitor your dog and contact your veterinarian if your pup shows any of these signs or symptoms in the days following contact:

  • Loss of energy

  • Loss of appetite

  • Vomiting

  • Stumbling/falling

  • Foaming at the mouth

  • Diarrhea

  • Convulsions

  • Excessive drooling

  • Tremors and seizures

  • Dermal irritation or rash

If you have any concerns or questions, please reach out to us. To report harmful algae blooms or receive further information for our region, please contact the Lahontan Regional Water Quality Control Board at (530) 542-5425.

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