AUSTIN (KXAN) — A toxin produced by blue-green algae that’s known to harm dogs has now been found in Lake Austin, according to the city.

Austin’s Watershed Protection Department urged pet owners Tuesday not to let their dogs eat or touch algae in any local lakes, creeks or bodies of water. This warning comes after the city detected dihydroanatoxin in an algae sample taken in mid-March from Lake Austin near Mansfield Dam.

“Although levels of the toxin are low, they indicate an increased risk for dogs in the water bodies,” the City said.

Toxic algae — called cyanobacteria — produces toxins and creates algae blooms, which appears to put dogs most at risk.

Cyanobacteria is blue-green in color and resulted in at least five dogs dying after swimming in the water in 2019. The city advises pet owners to rinse off their dogs if they do get in the water and take them to a veterinarian if they become sick after water contact.

Symptoms of toxic algae exposure include excessive drooling/vomiting, foaming at the mouth, jaundice, blood in urine, stumbling, loss of appetite, among others.

While risk to humans is low at the moment, the City of Austin says people should avoid handling algae at all.

On Tuesday, LCRA announced it also detected blue-green algae in Lake Travis. In March, the algae was found in Lake Travis, in addition to areas in Lake Marble Falls and Inks Lake.

According to John Higley, CEO of EQO, an Austin-based biotech company that helps manage invasive species, there’s one likely culprit contributing to the rise of blue-green algae. It’s another aquatic nuisance: zebra mussels.

These invasive, rapidly-producing, finger-sized mollusks arrived in North America in the 1980s, experts say. After invading the Great Lakes region, they began appearing all across the U.S.

Zebra mussels are razor sharp — easily cutting through clothing — and Travis County Parks officials said last summer that several swimmers reported injuries because of them. They attach to boats and most hard surfaces in water bodies, officials say.

Because they feed off “good” algae, experts say, and release blue-green algae back into the water.

Anyone who believes they have seen zebra mussels in Texas waterways is encouraged to email photos and location information to and report the sighting by calling (512) 389-4848.