Toxic Algae Blooms

3 min read
Jan 11, 2022

Whether it be swimming, chasing a stick, or just splashing about - most pups love spending time in the water.

While your pup may love spending time in the water, it is important to remember that all water is not created equally. While allowing your pup to spend time outdoors in the water to play, exercise, or keep cool in the summer months - it is important to check the types of bodies of water your furry friend is getting in. 

Different bodies of water can hold various dangers for your furry friend's overall health. Consider the following when your pup comes into contact with the following specific bodies of water:

  • Pools contain chlorine and other chemicals not intended for ingestion and should be washed from your canine’s coat after a dip. 
  • Ocean water is salty, which may itch your pooch if not rinsed off, and can cause gastrointestinal distress if consumed.
  • While waters containing Algal Blooms can be downright deadly to your best friend when your pup comes into contact with Algal Blooms.

Toxic Algae Blooms

Algae are non-flowering, plant-like organisms that grow in oceans, lakes, rivers, ponds, snow, and other damp environments. They can be tiny, single-celled organisms or as large as a kelp forest attached to the seafloor. 

Algae get most of their energy through photosynthesis, the process by which green plants and other organisms use sunlight to create food.  The byproduct of this production is oxygen, and blue-green algae are responsible for making half the oxygen on earth!  Nonetheless, blue-algae can be dangerous.


An algal or algae bloom occurs when there is a sudden increase or accumulation of algae in an area.  This is usually caused by an influx of nutrients (phosphorus and nitrogen), often from agricultural run-off, warm temperatures, sunlight, and still waters. 

The bloom can often be spotted by the discoloration in the water from the algal pigments.  These blooms are a result of blue-green algae, or more correctly -- a prehistoric bacteria referred to as cyanobacteria, which tends to thrive in late summer and early fall.  “Red Tide” is an example of an algae bloom, but scientists have moved away from using that term since blooms can produce a variety of colors and can be dangerous even when the water isn’t discolored at all.  

While half of the Cyanobacteria are not harmful to people and pets, there are several species that can produce a number of toxins.  These Cyanotoxins can result in skin irritation, allergic reactions, vomiting, diarrhea, and abdominal pain just from making contact with the bloom.  If your dog ingests water containing Cyanotoxins, he could suffer damage to the kidneys, liver, and central nervous system, resulting in death.

Protecting Fido

Since not all blue-green algae blooms are toxic, how do you protect your pet?  For starters, the presence of blooms indicates Cyanotoxins may be present, so…

1) Keep an eye out for signs, flags, or other methods local health authorities post to inform the public of water quality. Even if signs aren’t visible, look at the water and make sure the color is normal/clear before you let your dog dive in.

Blooms coat the surface with a scum ranging in color from brownish-yellows to reds and greens.  Since not all blooms rise to the surface, noticing murky or milky water could mean a bloom.  If you can’t see your feet or paws, don't go in!

2) Use a swim guide app to determine if the waterway you are planning to visit has passed water quality testing.

3) If you can’t immediately bathe your dog after a swim, have the ability to immediately rinse him with fresh water.  Know where the nearest animal emergency center is wherever you travel with your pooch, just in case he shows any signs or symptoms, which usually occur 15 minutes to several days after ingestion, and may include:

  • Diarrhea/vomiting
  • Drooling
  • Weakness 
  • Disorientation/confusion
  • Collapse/unconsciousness
  • Seizures
  • Breathing difficulties

4) Carry fresh drinking water at all times, so that your dog will be less inclined to sample lake or pond water.  Boiling water with Cyanobacteria does not reduce its risks.  That includes cooking fish caught in a lake contaminated by bacteria – paws off!  Additionally, dry algae on the shore can get crispy, and dogs will eat it.  The toxic effects here can kick in rapidly.

Be observant and never let your dog near water that could potentially be dangerous, wash Fido immediately anytime he goes for a swim or even dips paws, and if you suspect he has consumed toxic water, get to your veterinarian immediately!

Consider Investing in Dog Insurance  

Looking for more ways to keep your pup happy and healthy? Consider investing in a dog insurance policy with MetLife Pet Insurance.1  Get your free quote today. 

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1 Pet Insurance offered by MetLife Pet Insurance Solutions LLC is underwritten by Independence American Insurance Company (“IAIC”), a Delaware insurance company, headquartered at 485 Madison Avenue, NY, NY 10022, and Metropolitan General Insurance Company (“MetGen”), a Rhode Island insurance company, headquartered at 700 Quaker Lane, Warwick, RI 02886, in those states where MetGen’s policies are available. MetLife Pet Insurance Solutions LLC is the policy administrator authorized by IAIC and MetGen to offer and administer pet insurance policies. MetLife Pet Insurance Solutions LLC was previously known as PetFirst Healthcare, LLC and in some states continues to operate under that name pending approval of its application for a name change. The entity may operate under an alternate, assumed, and/or fictitious name in certain jurisdictions as approved, including MetLife Pet Insurance Services LLC (New York and Minnesota), MetLife Pet Insurance Solutions Agency LLC (Illinois), and such other alternate, assumed, or fictitious names approved by certain jurisdictions.