BOSTON — Before pets dash into the water to cool off this summer, Angell Animal Medical Center is warning owners about the potentially life-threatening risks of cyanobacteria, also known as blue-green algae.
“Typically, this time of year, concerns about cyanobacteria begin to increase,” said Dr. Courtney Peck, chief medical officer at MSPCA-Angell West in Waltham. “Late in the summer, warmer temperatures, increased sun exposure, and stagnant water create the perfect environment for blue-green algae to rapidly grow.”
Blue-green algae aren’t actually algae at all. Instead, they’re microscopic bacteria that use sunlight to make their own food, and can be found in fresh, brackish, and salt waters worldwide, she said.
“Humans and animals can both be affected, but while we’re often cautious of swimming in discolored water, dogs usually have no problem jumping right in,” Peck said.
Even if blue-green algae is not visible on the surface, that doesn’t necessarily mean the water is safe, she said.
“Sometimes there’s a ‘spilled paint look’ when water shows bright green, blue-green, brown or red streaks, but in some cases, toxic cyanobacteria can be present without causing a change in the appearance of the water, Peck explained.
Cyanobacteria, according to Peck, cannot be picked up in strands with a stick and will slip right through or look like a smear, unlike harmless filamentous green algae which forms clumps or stringy threads.
“Not all cyanobacteria are harmful. The only way to know this for certain is to test the water, so it’s best not to risk it,” she said.
In addition to avoiding letting pets swim in lakes and ponds during late summer and early fall, Peck recommends keeping a close eye on where pets stop to drink.
“It’s best to have fresh water on hand for your pet while out on walks,” she said. “You shouldn’t let them drink from still bodies of water, especially if there’s a foul odor or you’re able to see cyanobacteria or foam on the shore which can be a sign of a harmful algal bloom.”
Peck encourages owners to bathe pets immediately after swimming to prevent this secondary risk.
“Make sure to thoroughly wash your own hands after bathing your pet. Humans are more commonly affected through skin contact,” she said. “Before heading to a lake or a pond, check for updates from local and state agencies and look for posted signs warning of cyanobacteria once there.”
Signs a pet may have been exposed to toxic cyanobacteria include:
Muscle stiffness or tremors
Convulsions and/or seizures
Weakness or collapse
Trouble breathing
Discolored gums and/or tongue
Restlessness
Excessive drooling
Loss of bladder control
Vomiting and/or diarrhea
If pets develop these signs at home after spending time in or around water, Peck urges owners to seek veterinary care immediately.
Angell Animal Medical Center has around-the-clock emergency care in Boston and Waltham. Urgent care is also available in Waltham—to determine if a concern is an emergency or if it can be addressed at an urgent care visit, visit angell.org/urgent.