AUSTIN (KXAN) — The City of Austin confirmed the presence of toxic algae in “Barking Springs” after a sample was taken in the area where a dog died within an hour of swimming there last week.

The city began investigating on Monday, July 11, the day after the dog died. At the time, it said the dog’s cause of death was unknown, but toxic algae exposure was being considered a possibility. Now, the city said the confirmation of the presence of toxic algae increases the likelihood the dog was killed by accidentally ingesting harmful algae.

Barking Springs is part of Barton Creek, just downstream from Barton Springs Pool. City scientists observed isolated mats of algae near rocks in the area and took samples for testing that Monday.

The toxin present was identified as Dihydroanatoxin-a, a potent neurotoxin. It’s the same toxin that was present in algae in 2019 when several dogs died after swimming in Lady Bird Lake.

Because of the rapidly flowing water, Barking Springs is less likely to have a harmful algae bloom than slower-moving waterways, the city said. However, the harmful algae was found next to and attached to rocks in pockets of still water outside of the main path of the water. It underscores the fact harmful algae can be present in any natural waterway in Central Texas.

Harmful algae may be present in any natural water body in Central Texas at any time, especially in hot temperatures and drought conditions. It is more likely to be along shorelines and in pockets of warm, still water.

No toxins were detected in the water sample, according to the city. As long as the toxins are only found in the algae, exposure would occur by handling or ingesting algae. Ingestion of toxins in algae may be fatal. Dogs may be exposed by drinking the water, eating the algae or licking it off their fur. People can have symptoms from these toxins as well. Because humans are less likely to ingest the algae, the risk is lower.

There's some algae in the water near Barking Springs, as shown by this photo taken by the Austin Watershed Protection Department.
There’s some algae in the water near Barking Springs, as shown by this photo taken by the Austin Watershed Protection Department.

The city warns people should not drink or ingest water directly from Central Texas lakes or from any springs or creeks. Do not get in the water or allow your pets to swim or drink the water if it is warm or stagnant or if you see scum, film or mats of algae. It is always a good idea for both people and pets to rinse off after going for a swim. 

Protect your dogs from exposure to harmful algae by keeping them away from areas that are known to have harmful algae blooms. Earlier this summer, the City of Austin also detected toxins in algae samples at all monitoring locations on Lady Bird Lake, including Red Bud Isle, Auditorium Shores and Edward Rendon Sr. Metro Park, and at Emma Long Metropolitan Park on Lake Austin.

Toxic algae is not a new issue for Austin. In the last few years, there have been similar reports of dogs becoming sick or dying from algae exposure. The city also started treating Lady Bird Lake for toxic blue-green algae blooms after an area tested positive earlier this summer.

Know before you go

The city has a dashboard available to the public to check where crews have tested for the toxins and if the tests came back positive. Blue-green algae blooms thrive in warm, stagnant water, and the city has tested for the toxins at Auditorium Shores and the Festival Ramp, along with Red Bud Isle.

The dashboard also shows water temperatures and flow data for each of the testing sites. A mobile version of the dashboard is also available.

Symptoms and what to do about suspected exposure

If you, a family member or pet have sudden, unexplained symptoms after swimming, contact your medical provider, veterinarian or the Texas Poison Control Center at 1 (800) 222-1222. Also let the City of Austin know by completing their form. English and Spanish versions are available below:

People may experience symptoms ranging from skin or eye irritation to stomach pain, dizziness or even liver damage, depending on the extent of exposure. Mammals may show symptoms such as excessive salivation, vomiting, convulsions and more.

Read more information on symptoms on the Centers for Disease Control and Prevention’s website, Illness and Symptoms: Cyanobacteria in Fresh Water.