Diving into cool water can be a quick way to escape the summer heat, but during certain times of year, freshwater can pose hidden dangers to people and pets.
Lakes and canals can harbor toxic algae that swimmers and pet owners may not see or even know are there. A study published in the journal CurrentOpinion in Food Science by FIU researcher Schonna R. Manning, examines cyanobacteria, commonly known as blue-green algae, which can multiply rapidly in freshwater, forming blooms and proliferations, coupled with potentially deadly toxins.
According to Manning, some algal toxins can affect the nervous system, while others cause skin irritation or organ damage. For dogs, the risk can be even more serious because of the way they interact with water.
"Where humans can avoid consuming algae, dogs often do not because they're actively gulping the water while they swim," Manning said.
Dogs can also ingest algae and their toxins that get onto their fur after swimming.
"When they get out of the water, they groom themselves to clean off any stuff that may have gotten onto their coat," Manning said. "This can lead to accidental ingestion and create a tragic situation."
In severe cases, exposure to cyanobacteria can be fatal. Manning and her lab were the first to detect dihydroanatoxin, a very potent neurotoxin, in algal mat materials; this toxin was suspected in several canine fatalities and published in the journal, Data in Brief. Later, Manning studied a case in which a dog died within two hours of accidentally consuming algae, published in Toxins, where the neurotoxin was detected in the dog's digestive system just prior to death. Because these events can happen unexpectedly, her team has been working on understanding the environmental factors leading to the formation of toxin-producing blooms.
Cyanobacteria are just one group of organisms that can occur in aquatic environments, and not all algae produce dangerous toxins. But certain cyanobacterial blooms can be concerning because of the toxins they produce.
Manning said harmful algal blooms occur more frequently during warmer months. When water temperatures rise, conditions can become more favorable for algae and bacterial growth, especially when excess nutrients enter rivers, canals, lakes, and other waterways.
Manning said pet owners should watch for water that appears unusually discolored or contains surface scum, floating clumps or mats of algae.
"If it looks bad and smells bad, go somewhere else," Manning said.
Manning also recommends paying attention to public health alerts about harmful algal blooms and warning signs posted at lakes and canals.
"We have to be aware of what's around us so that we can recreate safely, not only ourselves, but with our fur friends as well," Manning said.
Alerts for active toxic-forming algae and water quality testing results are available for Miami-Dade County through the state's Protecting Florida Together dashboard and the Florida Department of Health in Miami-Dade County.
Freshwater Dog-Friendly Checklist
Ensure that a body of water is safe for your pet before you allow it to dive in.
1. Check online before heading out. Municipalities and counties often post alerts and current water quality information on websites.
2. Look for posted warnings onsite. Thoroughly read and abide by posted warnings about harmful algal blooms in lakes, canals and other waterways. If it's not safe for people, it's not safe for your pet.
3. Avoid water that smells bad, looks unusually discolored or has surface scum, floating clumps or mats of algae.
4. When in doubt, stay out. This applies to people and pets.
5. Check your dog's fur: Dogs may groom themselves after swimming and accidentally ingest algae or toxins that have collected on their coats.
Alerts for active toxic-forming algae and water quality testing results are available for Miami-Dade County through the state's Protecting Florida Together dashboard and the Florida Department of Health in Miami-Dade County.
