HOLY TOLEDO! BLUE GREEN ALGAE AND TOXICITY

After quite a wet summer here, I read with great interest the shutdown of the public water supply to Toledo, Ohio. It was due to a Blue Green Algae bloom at the intake valve in the western part of Lake Erie. Boiling the water would NOT eliminate the toxin; in fact, it would increase the concentration of the toxic poison, microcystin.  Over 400,000 people were forced to drink bottled water for 3 days (could take showers & wash their hands as detected levels of the toxin were low), until the public water supply was deemed safe.  

Factors leading to the water supply shutdown (a potential risk for decades in the Lake Erie area), include fertilizer runoff, sewage, industrial pollution, and agricultural discharge from the Maumee River. In addition, warming of the water itself through environmental changes including heat zones from the nuclear power and coal burning plants's water discharge have encourage the algae to grow at alarming rates in warm , summer months.  Other areas of the world such as the Baltic Sea area have experienced similar bloom concerns.

In the southeastern United States the blue green algae form on stagnant ponds and is called “pond scum”. Although not all algae exposures are toxic, it raises the question how safe is it for dogs to go in these ponds?  This leads to today’s blog story of Blue Green Algae Toxicity.

WHAT IS BLUE GREEN ALGAE BLOOM?  WHY ARE PETS MORE AT RISK?

 It is a photosynthetic,  cyanobacteria  (NOT CYANIDE) that looks like “green paint” as it grows in fresh water when the sunlight, nutrient levels, and water temperature are at high levels, especially in summer months.  Pet owners should note these smelly, microscopic bacteria also can be blue, red, or brownish in color.  Several toxins are stored within the algae cells. Microcystins and anatoxins are the most common.   Even if the water surface is clear there can be algae blooms suspected at various levels beneath the surface. Pets are more at risk of toxicity as they are unselective of the water quality of where they drink or swim.

IS WATER CONTAMINATED BY THE SIMPLE PRESENCE OF THE CYANOBACTERIAL BLOOM?

No. Thirty to fifty percent of the algae blooms are harmless because they contain only non-toxic species. However, it takes a laboratory analysis to determine the difference and determine if a body of water is safe.

HOW DOES A PET OWNER RECOGNIZE BLUE GREEN ALGAE TOXICITY?  

Besides a green staining around the muzzle and local skin irritation & rashes, often acute vomiting, diarrhea, and weakness will be noted.  In addition, pet owners may notice lethargy, difficulty breathing, drooling, staggering, and abnormal urination as soon as 15 to 20 minutes after ingestion. The microcystin toxin (same one that contaminated Toledo water supply) will lead to liver failure within 12 to 24 hours. Seizures may develop in many pets so acutely after exposure there is not time to seek emergency care. Other than supportive care, there is no antidote for these toxins.

Veterinarians in testing exposed pets will often find low blood sugar, rising liver enzymes, and abnormal clotting time

CAN AN OWNER SEE THE BLUE GREEN ALGAE?

Not always, so if in doubt, keep children and pets out of the “Pea soup water” area, especially along the shore line as the wind often blows concentrated amounts of the algae to these areas.

WHERE CAN A PET OWNER DO IS ACUTE EXPOSURE IS SUSPECTED?

Wash off your pet with bottle water, soap, or any non-contaminated water supply. Do not allow your pet to lick itself. Wear gloves to avoid your own contamination.

I AM CONFUSED? ISN’T THERE A FOOD SUPPLEMENT, BLUE GREEN ALGAE?

Yes, this supplement is consumed for the touted benefits to improve energy and mood. Off label use is the treatment of Attention Deficit Disorder, although the benefits are unproven.  The Spirulina variety harvested from controlled ponds or natural lakes does not contain microcystins.  However the non-Spirulina blue green algae (ex. Aphanizomsnon flos-aquae) may contain unsafe levels of microcystin when consumed according to manufacturer recommendations. Caution should be applied when using such products as food supplements are not regulated by the FDA.  

Betsy Sigmon DVM, Diplomate American Board of Veterinary Practitioners

Creature Comforts Animal Hospital

Cary, NC