Dogs and Toxic Algal Blooms: A Warning for Pet Parents

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PetMD Editorial
Published: July 31, 2017

In the last several years, reports of dogs getting sick or dying after swimming in ponds, lakes, and streams have become more common.

Most recently, a 16-month-old Black Lab named Alex fell ill after swimming in a New York reservoir that, unbeknownst to his owner, had an outbreak of harmful algae, according to a report from EcoWatch. "Alex later collapsed and was immediately rushed to the vet,” the article stated. “Unfortunately, despite treatment, he died five hours later from cyanobacteria neurotoxins, one of the toxins found in algal blooms."

In another recent tragedy, two dogs died after swimming in a pond in Napa County, California, that contained toxic blue-green algae, the Sacramento Bee reported. Warnings of similar algae blooms have been popping up more and more in California. 

These stories, in addition to the hundreds of other reported cases by the CDC, have touched a nerve with fellow pet owners, especially those who take their dogs near bodies of water. The Department of Environmental Conservation (DEC), in conjunction with veterinarians, scientists, and the New York Sea Grant, created a helpful guide about the dangers of harmful algal blooms and the deadly impact they can have on dogs.

Toxic algal bloom are visible scums found in bodies of water like ponds, lakes, and puddles, where dogs can often be found playing or even drinking. Exposure to these toxins can lead to poisoning or even death.

According to the guide, these blooms typically occur after periods of warm, sunny, and calm conditions during the summer and fall, at water temperatures between 60 to 86 degrees Fahrenheit, or due to runoff after a big storm. Dr. Christopher Gobler, a professor at Stony Brook University and one of the guide’s contributors, told petMD that global warming may also have an impact because "warmer temperatures make blooms more intense, as does excessive nutrients from wastewater or fertilizers." 

Dogs are more susceptible than humans to toxic algae poisoning because of their behavior, the DEC guide explains. "When toxins are present, dogs can be exposed to toxins by drinking the water, by eating washed up mats or scum of toxic cyanobacteria and by having skin contact with water. Dogs are often attracted to algal scum odors. After leaving the water, dogs can also be poisoned by grooming their fur and paws." 

If a dog has been poisoned by a toxic algal bloom, some of the signs and symptoms include repeated vomiting, diarrhea, seizures, hives, rashes, difficulty breathing, loss of appetite, and drooling, among others. In more extreme cases, a dog can die from being exposed to toxic algal blooms in water.

If a dog has been playing in or even drinking infected waters, signs can begin to show up in as little as a half an hour after exposure. Even scarier, there can be delayed effects from longer or repeated exposure. While all dogs are at risk, smaller dogs (those weighing less than 40 pounds) are expected to have higher health risks when exposed to high toxin concentrations.

If you suspect your dog has been exposed to a toxic algal bloom (which the DEC describes as appearing "foamy or like pea soup, spilled paint, colored water; also as scum or floating mats"), it is imperative that you seek immediate veterinary care. 

To avoid contact all together, the DEC suggests keeping your dog out of these bodies of water. If your dog does enter the water, "rinse/wash them thoroughly with fresh water from a safe source if available (i.e. bottled water or household garden hose). Otherwise, a towel or rag can be used to remove algal debris." The guide also recommends using rubber gloves while you clean your pet. 

The DEC warns that these water-based toxins "are increasing in many areas" and "the number of dog poisonings from cyanobacterial toxins is also on the rise." 

Image via Shutterstock 

Read more: 7 Scary Diseases Your Dog Can Get from Water