How Blue-Green Algae Can Harm Your Dog

dog lake toxic algae cyanobacteria

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There's a type of blue-green algae that can poison animals, and it's enough to worry pet owners everywhere. This scary summertime hazard is life-threatening to dogs and other animals, including humans. Find out how to keep your pets safe from algae intoxication.

What is Toxic Algae?

Often called blue-green algae, this toxin is technically cyanobacteria, not algae. Cyanobacteria are photosynthetic organisms, meaning they get their energy from the sun. These organisms use carbon dioxide, water, and sunlight to produce glucose, oxygen, and water. They can also produce dangerous toxins.

Cyanobacteria contain toxins that are harmful or fatal to most animals. The growth of algae is often referred to as "blooms." Cyanobacteria are known as "Harmful Algal Blooms" or HABs.

Cyanobacteria look like algae and bloom in a similar manner. Blue-green algae thrive in warm, sunny temperatures and freshwater environments. Cyanobacteria can sometimes live in saltwater or brackish (mixed) bodies of water. Blue-green algae can even form in aquariums.

Blue-green algae/cyanobacteria blooms may appear as a greenish-blue, red or greenish-brown film floating on the water. It may appear slimy, foamy, or look like "pond scum" that gathers near the shoreline. Not all contaminated bodies of water will have obvious algae blooms; the water may simply appear murky or dirty. In addition, water contaminated with cyanobacteria often has a foul odor.

Because warm temperatures promote the growth of cyanobacteria, intoxication is most likely to occur in the summer months. If ingested, the toxin is extremely dangerous to most animals, including dogs, cats, wildlife, fish, birds, livestock, and even humans.

Signs of Algae Intoxication in Dogs

Toxicity occurs after ingestion of harmful blue-green algae. Dogs are most likely to be affected after swimming in water that contains cyanobacteria. This is because dogs tend to ingest water while swimming. They may also lick the toxin from their coats after swimming. It only takes a small amount of contaminated water to lead to poisoning.

Cyanobacteria can contain a few different types of toxins. They can cause damage to the liver, kidneys, skin, and nervous system. Sadly, cyanobacteria poisoning is often fatal to animals.

Signs of Blue-Green Algae Toxicity

Symptoms may appear as quickly as 15 minutes after exposure. Most animals will show signs within one to two hours after ingesting the toxin. Some types of cyanotoxins will take up to 24 hours to appear. Always observe your pets closely for any sign of illness.

  • Panting
  • Shortness of breath
  • Labored breathing
  • Excessive drooling
  • Discharge from eyes
  • Vomiting
  • Diarrhea
  • Disorientation
  • Dizziness
  • Ataxia (drunken gait)
  • Paralysis
  • Muscle tremors
  • Seizures
  • Pale, white, yellow, or blue mucous membranes
  • Black or bloody stool

What to Do If Your Dog Is Exposed to Toxic Algae

If you suspect your pet has been exposed to blue-green algae/cyanobacteria, you should consider this an emergency situation. Bring your pet to the nearest open veterinary office immediately. There is nothing you can do at home to treat this. Inducing vomiting is not effective due to the rapid absorption of the toxins. Your veterinarian is your pet's only chance of survival.

Unfortunately, there is no antidote for cyanobacteria poisoning. Treatments are available to offer supportive care and manage the symptoms. Your vet will likely administer intravenous fluids and provide medications to alleviate or prevent symptoms. Your pet will likely need to be hospitalized for intensive care.

How to Keep Your Dog Safe From Toxic Algae

The best way to protect your pets from toxic blue-green algae is to keep them away from bodies of water that may contain the toxins. Do not let your pet swim in, wade through, or drink from water that looks stagnant, murky or dirty, has an odor, or appears to have algae on the surface. Note that algae may not always be easy to spot. When in doubt, keep your pet away from any water that is not flowing, clear, and odorless.

If your dog has been in a body of water that seems suspicious, use a hose to rinse off all residue immediately. If you are concerned that your dog ingested some of the water, it's best to contact your vet just in case.

To avoid accidental contact with contaminated water, avoid allowing pets to roam free. Keep your dog on a leash or in a fenced-in area. Keep cats indoors or in secure outdoor enclosures while supervised. Prevention is the key to preventing a tragic fate.