Dog owners in at least three states have internalized a sobering fact lately: Blue-green algae can indeed be as deadly as the warnings that scientists have issued for years.

“It’s no joke and it’s not an over-precaution to keep your dogs and your kids out of the water,” said Tom Bridgeman, University of Toledo Lake Erie Center director and an ecology professor who specializes in algal blooms.

In addition to three dogs dying from an algal toxin near Wilmington, N.C., earlier this month, there have been reports of at least one dog in Texas and another in Georgia dying of the same thing, although not necessarily the same toxin. There also have been scattered reports of dogs dying from exposure in the Lake Erie region over the years, though not yet this year. 

Bart Soeder, a South Toledo veterinarian who for years has run Heatherdowns Veterinary Clinic, 2454 Cass Rd., agrees dogs “could be at pretty significant risk” if exposed to microcystin, western Lake Erie’s chief algal toxin.

Microcystin is one of four algal toxins around the world that an Ohio Environmental Protection Agency researcher and others have ranked among the most potent waterborne toxins, the others being saxitoxin, cylindrospermopsin, and anatoxin.

Some, such as anatoxin, act more quickly than others.

Such toxins, on the rise globally, can shut down livers and cause neurological impairments. Dogs are especially vulnerable because of their smaller body mass and their tendency to be drawn to “disgusting” stuff, Dr. Soeder said.

“It’s impossible to police them 100 percent of the time,” he said.

If you think your dog has played in or ingested part of an algal bloom, about all you can do is wash off its fur with fresh water so that it doesn’t ingest more by licking. There is no clinical diagnosis or antidote, Dr. Soeder said.

“If it’s a severe situation, we’re really limited on what we can do,” he said. “As soon as you get your dog out of the water, go rinse him off with fresh water.”

Three western Lake Erie algae researchers agreed the best advice is prevention. Keep your dog on a leash if you’re walking them near a suspicious area.

Don’t rely too heavily on sampling results, Mr. Bridgeman said. Toxin levels can be much more concentrated on a beach or along a shoreline when scums are pushed together by wind, he explained.

“Unfortunately, this isn't a 2019 problem,” Tim Davis, a Bowling Green State University algae scientist, said. “It's not a local problem, either. These type of events have been occurring for several years.”

Also, don’t assume your pet will be discriminating enough to know not to ingest algae.

“Dogs will eat dead animals and horse poop. Algae won’t turn them away,” said Justin Chaffin, Ohio Sea Grant and Ohio State University Stone Lab research director. “If you see [the water] is green, keep them on a leash.”

Fish and other wildlife are susceptible to algal toxins too. Many fish know instinctively to stay out of blooms and other conditions in which oxygen in the water has been reduced. Some move to deeper and cleaner water long before blooms set in, he said.

“Nobody does autopsies on fish unless there’s a mass die-off,” Mr. Chaffin said. “It’s hard to document wildlife directly. Nobody’s looking for dead deer or muskrats.”

Researchers agree it’s unfortunate that people all over the world are becoming more wary of lakes, ponds, and rivers, especially when vacations typically occur during summer months.

“Most people know what a lake should look like,” Mr. Davis said. “When it doesn't, you should stay out of it.”

First Published August 18, 2019, 7:06 p.m.