• Jolene Seville
  • Dog Nutrition and Member Service Specialist

  • 3 mins read time
  • Protecting Your Dog From Toxic Blue Green Algae

    During the summer months you may hear news reports about toxic blue green algae and the devastating effects it can have on our dogs. This potentially deadly algae is something all pet parents should be aware of, even if your dog doesn’t spend much time around water.

    What is toxic blue green algae?

    Algae is a cluster of cyanobacteria that usually grows in warm, slow moving, or stagnant bodies of water like ponds and lakes. While there are many types of algae, like healthy spirulina, some can have negative, and even deadly, effects on the body.

    Some strains of algae produce cyanotoxins. These toxins can cause damage to the nervous system (anatoxins) and liver (microcystins). If a dog ingests these cyanotoxins it can result in severe illness, organ failure, and even death.

    Microcystins will damage the liver and can result in organ failure and death within 24 hours. The liver is an extremely important organ with many functions including detoxing the blood and aiding in digestion. As a result, dogs exposed to microcystins may experience vomiting, diarrhea, or dark and bloody or sticky poop. As the liver fails to filter toxins from the body, the dog may experience seizures and even fall into a coma before full organ failure and death.

    Anatoxins attack the nervous system and can also lead to death within hours. As the nervous system is damaged, dogs may experience muscle paralysis or tremors, difficulty breathing, or heavy drooling. Rapid respiratory failure can be a result of the diaphragm becoming paralyzed, leading again to coma and death.

    How dogs can be exposed

    Since this algae grows in slow moving bodies of water, dogs can easily be exposed on hikes or a day at the lake! They may drink the water or have it transferred into their mouth by a contaminated toy. They can even ingest it by licking their coat later after swimming!

    Any stagnant body of water is potentially contaminated, especially during the warmer summer months, so it’s wise to be cautious around stock tanks and horse troughs as well. It’s important to be aware of the potential threat anytime you take your dog near water and take proper precautions including researching the spot ahead of time, rinsing your dog immediately and leashing your dog where you are unsure.


    A dog may display any of the following symptoms if they have been exposed to toxic blue green algae. Symptoms may appear within minutes but can show up up to 24 hours later.

    • Weakness

    • Disorientation

    • Heavy panting

    • Trouble breathing

    • Excessive drooling

    • Tremors

    • Paralysis

    • Vomiting

    • Diarrhea

    • Seizures


    It is imperative that your dog receive medical attention immediately if you believe they have ingested algae! If you notice any symptoms after they swim in or drink from a questionable water source, do not hesitate to get veterinary care or call the Pet Poison Hotline. They can be reached 24/7 at 855-764-7661.

    Because these toxins act so quickly any chance of recovery will rely on immediate action. Vets may induce vomiting, administer activated charcoal, or pump the stomach. Dogs may also be given fluids, anti-seizure medications or muscle relaxers and medication to support the liver.

    There is no cure or antitoxin for blue green algae, and even with vet care most dogs will not survive. In fact, these toxins act so fast most dogs will pass before reaching veterinary care, which is why prevention is imperative. Dogs that do survive have intense treatment ahead of them. They may experience permanent organ damage but some like this pup, went on to live a normal life.

    How to avoid contamination

    Local reports - While there is no way to be 100% sure of a body of water’s safety, you can often find helpful information online. Many areas that experience algae blooms do regular testing on popular bodies of water. Contact your state’s Department of Health for information on reported blooms.

    Stick with tested locations - It’s nice to have a secluded pond to yourself but smaller, less popular bodies of water aren’t usually tested. Try to stick with pet friendly lakes and ponds that local authorities are frequently assessing.

    Visual inspection - Blue green algae is often visible on the surface of ponds and lakes. It may appear as a green scum and frequently it will collect near the shore line. The water may also have a bad smell. But be aware, it will not always be visible, especially during windy conditions.

    Be cautious - If you’re ever in doubt, it is safest to not allow your dog near the water. Not all algae will be visible. If your dog gets into a body of water you are unsure about, be sure to thoroughly rinse them off as soon as possible and monitor for any symptoms.

    Check EWG maps - The Environmental Working Group tracks news updates on algae blooms and has a great map of known contaminations. Do not rely solely on this as not all blooms are reported.

    Toxic blue green algae can present across all of North America but is most commonly found in areas with warm water (over 77 degrees fahrenheit is ideal) and high humidity. Late summer and early fall are the most common times for algae to bloom but don’t assume your dog is safe in the “off season.” Heat waves and unseasonably high water temperatures can create a bloom as well.

    When it comes to our dogs and their safety, it is always best to be cautious especially when it comes to algae intoxication. If a body of water seems scummy, smelly or in any other way questionable, do not allow your dog to get near it. Always report potential blooms to your state’s Department of Health so you can help protect other dogs from this very serious and deadly bacteria.