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Dear Critter Chatter,

I received a warning e-mail this week about a dog that died from drinking water that had blue-green algae in it. We are going to the cottage next week with our two dogs and wonder if our lake has blue-green algae in it. Is this a hoax e-mail? Should we keep our dogs out of the water?

– North York Mirror reader

 
Dear Reader,

I also received that e-mail and from what I know it is not a hoax.

To update other readers, the e-mail was referring to a nine-month-old border collie that had been swimming in a body of water in Michigan State on a hot day. After vomiting up water several times, she lay down and closed her eyes.

The owner suspected heat stroke and took the dog to a nearby emergency clinic. By the time they arrived at the clinic the dog was non-responsive, her breathing was slow, heart rate was elevated and her eyes were fixed and dilated.

The vet suspected toxic poisoning as he had recently seen two other dogs with similar symptoms that had been diagnosed with blue-green algae toxicity.

The owner left his dog on a ventilator at the clinic that evening and went home to learn more about the toxin that held his dog's life in its balance. While researching he found that swallowing water that has cyanobacterial toxins in it can cause acute, severe gastroenteritis, including diarrhea and vomiting. It can also cause neurotoxicity, which in dogs can cause neurologic symptoms such as salivation, weakness, staggering, difficulty breathing, convulsions and even death.

Tragically, his border collie did die the next day from the effects of blue-green algae toxicity.

I did some research and found the following information. If you do an Internet search of blue-green algae toxicity, you can find much more.

Algae are common in surface waters and are microscopic plants that are a natural part of any aquatic environment. There are hundreds of species of algae, most of which are harmless, but the family of blue-green algae called cyanobacteria can produce toxins that affect humans and animals. Cyanobacteria typically form in shallow, warm, slow-moving or still water.

While blue-green algae can be present throughout the year, problems don't occur until there is an extensive "bloom". There is no single factor that causes an algae bloom. A combination of factors such as excessive nutrients, warm temperatures and lots of sunshine all encourage the growth of blue-green algae.

In nutrient-rich water they can become so abundant that they completely dominate other free-flowing algae. Then the whole appearance of the water may change. It will become cloudy, with a green, yellow or blue-green hue. While many algae can turn water green, a lake with blue-green bloom may look like pea soup or like there is green paint floating on the surface. It may develop a "swampy" odour as the algae accumulate in large floating mats and begin to decompose. In extreme cases there may be surface scum.

People are seldom seriously affected by toxic algae because we tend to avoid water that has an unpleasant odour and appearance, but since the first recorded incident of animal poisoning caused by blue-green algae in Australia in 1878, both wild and domestic animals have been killed by it.