The city of Austin is investigating the death of a dog that died after swimming in Barton Creek, looking at toxic algae as a possible cause.

On July 10, the city of Austin was notified by a veterinarian that a large, adult dog with no known health issues had died around an hour after swimming at "Barking Springs," a section of Barton Creek next to the Barton Springs Municipal Pool.

Now, the Austin Watershed Protection Department and Austin Public Health are trying to learn more about the cause of death, testing for toxins in algae samples found at the site, said Joan Esquivel, Austin Watershed Protection Department public information specialist.

“Many other dogs may have played in the same vicinity at the same time, and there have been no other reports,” Esquivel said. “Please be aware that in situations like this we may not come to a definitive conclusion.”

City scientists took samples from mats of algae found near the area July 11 with results expected to come back during the week of July 17, Esquivel said. Until then, the city is advising against swimming in Barking Springs.


“The best way to protect yourself and your dogs is to avoid swimming at Barking Springs until we have test results,” Esquivel said. “As far as other water bodies are concerned, we recommend avoiding algae mats, including areas with known harmful algae blooms.”

With recording-breaking hot temperatures and a drought underway, conditions are ripe for harmful algae, according to the department. Warm water with low flow and high nutrient levels allow blue-green algae or cyanobacteria to produce toxins dangerous to the health of humans and pets.

In May and June, toxic algae was detected at Red Bud Isle and in June at Lady Bird Lake and Emma Long Metropolitan Park on Lake Austin. As toxins were detected in the algae and not the water, contamination may only happen through ingesting the algae, putting pets most at risk.

In 2019, five dogs died from toxic blue-green algae blooms in Lady Bird Lake. Pets may be exposed from drinking the water or ingesting or licking algae from their fur. Symptoms include excessive salivation, vomiting, fatigue, staggered walking, difficulty breathing, convulsions and liver failure, according to the Centers for Disease Control and Prevention.


Given this summer’s hot and dry conditions, the department is warning that harmful algae may be found in any body of water, most commonly forming along shorelines, still water and pockets of water.

To avoid contact with toxic algae, people and pets should avoid water that is warm or stagnant or has scum, film or algae mats. The department also recommends rising off after swimming.