Dangers of Cyanobacteria, protect your dog from mucky waters

Cyanobacteria in dirty water can kill dogs

Letting your pet take a dip is great, but watch out! Cyanobacteria in water are a major risk to dogs.

Indeed, these tiny organisms cause fatal poisonings in our four-legged friends every year. Found in rivers and at sea, caution is essential. Nature & Garden informs you on how to keep your dog safe.

What are cyanobacteria?

Identify cyanobacteriaFirst off, it’s good to know cyanobacteria are nothing new: they have been around for 2 to 3 billion years. They exist in plants, water, and sand. They thrive in light, warmth, and nutrients, which is why they love summer and warm ponds. To survive, as part of their lifecycle, they produce toxins.

Sadly, these can turn deadly for dogs. Specifically, the toxins involved are hepatotoxins (affecting the liver), dermatotoxins (skin issues), and neurotoxins (death from respiratory muscle paralysis).

During heatwaves, cyanobacteria boom. Without heavy rain, their concentration increases, forming green or blue layers on water surfaces or spongy, black clumps at the bottom. Water samples are the only way to identify which toxin type is prevalent in a specific area.

How do dogs get exposed?

Dogs can get poisoned by cyanobacteria in three distinct ways:

  • swimming in fresh or salt water;
  • drinking contaminated water;
  • or making contact with a tainted surface.

Warning symptoms

Symptoms of cyanobacteria infectionClinical signs of poisoning show up barely minutes after contact with cyanobacteria. The severity is proportional to the type and amount of toxin the bacteria releases.

  • Hepatotoxins lead to symptoms such as vomiting, diarrhea, lethargy, liver failure, coagulation disorders, and drooling.
  • Dermatotoxins cause skin and mucous membrane irritation.
  • Neurotoxins bring on the most severe symptoms: paralysis, respiratory distress, seizures, and even death.

Treatment for dog cyanobacteria poisoning:

Sadly, no specific treatment exists. If hepatotoxins or dermatotoxins poison a dog, a vet alleviates visible symptoms like seizures or diarrhea and might induce vomiting. This helps your pet overcome the poisoning.

However, heavy neurotoxin poisoning results in rapid death for your pet, around 30 minutes.

As a result, cyanobacteria pose a genuine threat to dogs, and prevention remains their best protection.

How to protect your dog?

  • How to protect your dog from cyanobacteriaKeep an eye out for any green or bluish surfaces on the water.
  • Under the water, especially in rivers, avoid all clusters of blackish sponge-like material (sometimes it floats instead).
  • On your walks, bring along fresh water for your dog to drink from. This prevents your dog from lapping up contaminated water sources (cloudy with bluish reflections).
  • Keep your dog leashed in risky areas. When a suspicious death is reported, water samples are taken for analysis, and typically, authorities post a sign that prohibits swimming with the reason stated (humans are also at risk).
  • Check with your local town hall, the tourist office during vacations, or dedicated websites to identify affected areas.
  • Rinse your dog’s fur thoroughly after every summer swim.

Smart tip

Did your dog take a risky dive? Don’t wait for symptoms to appear! Get them to your vet or an emergency vet clinic ASAP. Time is of the essence!


Images: 123RF: ibpstock, pytyczech; Pixabay: Светлана Бердник, Joshua Choate

Written by Lydie Dronet | With over 20 years in the field of animal care, Lydie shares her paws-on expertise and experience. Other topics she loves delving into are nutrition and the medicinal uses of plants.