blue green algae3

As the summer heats up, many of us are taking to the water to relax and keep cool with our dogs.

But if you see any algae in the water, make sure to steer clear.

Some blue green algae produce a toxin that can be deadly. Earlier this week in Minnesota, it was confirmed that it’s already resulted in one dog’s death.


Blue green algae may look like algae but it’s actually bacteria.

Commonly referred to as “cyanobacteria,” or just called “blue-greens,” both names describe the color of water harboring this bacteria. Cyanobacteria can form a scum that looks like pea soup or paint on the surface of the water and can evnetually take over a body of water by blocking out the sunlight for other aquatic plants. The scum that floats on the water is called “blooms” and they’re usually enough of a deterrent to keep people from swimming in the water, but your dog may not mind so it’s up to you to keep him safely away from any water that might carry this deadly bacteria.

In a paper released by Purdue University, it’s noted that toxicity is actually rare among blue green algae. We don’t know what causes the bacteria to be able to make toxins and there’s no way to differentiate between benign or deadly bacteria blooms, so it’s best to simply avoid any water that has blue-greens in it.

Most of the danger to humans comes from skin exposure and can cause irritation, such as a rash or even blistering.

The same is true for pets, but it becomes deadly if the dog licks himself clean or swallows some infected water.

And symptoms can appear very quickly.

One of the dogs reportedly killed by cyanobacteria last summer ( was affected very quickly.

“We were playing fetch in the water when he went on shore, began vomiting and panting very hard, and just looked very sick” said his owners. They rushed the dog to the vet immediately but, even with treatment, the prognosis is often poor.

The Pet Poison Helpline classifies its level of toxicity as “generally moderate to severe” and notes that “very small exposures, such a few mouthfuls of algae-contaminated water, may result in fatal poisoning.”

Symptoms Of Cyanobacteria Poisoning

Blue green algae can produce two different toxins that produce different symptoms.


Microcystins is the toxin that causes liver failure and you may see vomiting and diarrhea with bloody stool and lethargy, as well as pale mucous membranes and jaundice.


Anatoxins are a neurotoxin and usually cause muscle tremors, seizures, and paralysis.

Dr Lynn Hovda, director of veterinary services for the Pet Poison Helpline, notes that both toxins can cause clinical signs and death from anatoxins can occur as quickly as 30 to 60 minutes after your dog is exposed to the toxins. With microcystins symptoms may take 12 to 24 hours to appear, but it’s still critical to get your dog to a vet.

You’ll want to watch for any of the following symptoms:

  • Diarrhea
  • Vomiting
  • Blood in stool or black, tarry stool
  • Pale mucous membranes
  • Jaundice
  • Abnormal blood clotting
  • Elevated liver enzymes
  • Low blood sugar and protein levels
  • Seizures
  • Disorientation
  • Coma
  • Shock
  • Excessive secretions (salivation, tearing, etc)
  • Neurologic signs (muscle tremors, muscle rigidity, paralysis, etc)
  • Blue discoloration of the skin and mucous membranes
  • Difficulty breathing

What You Can Do If You Suspect Cyanobacteria Poisoning

  • If your dog has gone into waters that you suspect might be affected, it’s important to remove him from the water and hose him off immediately, to prevent him from licking and swallowing any of the water.
  • You may choose to take him to the vet, or if your dog looks fine but you’re not sure the water is unsafe, you can choose to watch your dog carefully for symptoms.
  • You can also consider using homeopathy after exposure, to prevent any illness:
  • If your dog has been swimming in questionable water and he’s not showing any immediate symptoms, try giving him Arsenicum album 30C or Nux vomica 30C as soon as you can.
  • If your dog is showing signs of poisoning, you can continue giving him Arsenicum album 30C every 10 to 15 minutes on the way to the vet or Carbolic acid if you can get it. These remedies won’t replace the emergency veterinary care he’ll need, but they can help reduce symptoms, especially if it’s accompanied by anxiety, diarrhea and weakness.

Confused about remedy dosages? Click Here

Keep your dogs safe this summer and always be aware of any blue-green algae in water they have access to. Just remember that it’s easier to avoid the algae than to attempt treatment after exposure.