Toxin harmful to dogs found in Austin's Barking Springs algae sample

Roberto Villalpando and Kelsey Bradshaw, Austin American-Statesman
·4 min read

Algae samples taken at Barking Springs, a popular wading area downstream from Austin's iconic Barton Springs Pool, have tested positive for a potent neurotoxin after the city earlier this month reported that a dog had died July 10 within an hour of swimming there.

Austin's Watershed Protection Department, in a statement Friday night, said the presence of dihydroanatoxin-a increases the likelihood that the dog ingested harmful algae.

"Dihydroanatoxin-a is the same toxin that was present in algae in 2019 when several dogs died after swimming in Lady Bird Lake," the department said.

So far this summer, the city has found toxins in algae samples, but not water samples, at its monitoring locations, with three sites on Lady Bird Lake and three sites on Lake Austin, including one at Emma Long Metropolitan Park. Watershed Protection Department staffers have been checking the sites every other week throughout the summer.

Lady Bird Lake is susceptible to harmful blue-green algae blooms that produce toxins deadly to dogs.
Lady Bird Lake is susceptible to harmful blue-green algae blooms that produce toxins deadly to dogs.

Earlier this summer, the city of Austin detected toxins in algae samples at all monitoring locations on Lady Bird Lake — Red Bud Isle, Auditorium Shores and Edward Rendon Sr. Park at Festival Beach — and at Emma Long Metropolitan Park on Lake Austin. Algae samples collected from Lady Bird Lake on June 27 and from Emma Long on June 29 contained homoanatoxin, a neurotoxin.

Last summer, the city began treating 22 acres near Red Bud Isle, upstream on Lady Bird Lake, with a claylike substance called Phoslock to slow or stop the growth of  toxin-producing blue-green algae. This year, the Watershed Protection Department expanded its use of Phoslock to the north shore of the lake in East Austin, from Interstate 35 to the lagoon by the Festival Beach boat ramp.

Water dangers:Dog dies after being at Barking Springs

Harmful algae is more likely to be found along shorelines and in warm, still water. Barking Springs, a public spot for people to bring their dogs to play and swim free of charge, sits on the other side of a spillway at the downstream end of Barton Springs Pool, which requires a fee to enter and does not allow non-service dogs.

"Because of the rapidly flowing water, Barking Springs is less likely to have a harmful algae bloom than slower-moving waterways," the Watershed Protection Department said in its statement Friday. "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 that harmful algae can be present in any natural waterway in Central Texas."

Because the toxins are not in the water samples and only found in the algae, "exposure would occur by handling or ingesting algae," city officials said.

"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," according to the city. "People can have symptoms from these toxins as well. Because humans are less likely to ingest the algae, the risk is lower."

IF you do take your dog swimming, make sure to rinse yourself and your dog off after swimming and keep your dog from licking its fur before you rinse it off. If your dog becomes sick after swimming, take it to a veterinarian immediately.

Symptoms of algae poisoning in dogs can pop up minutes to hours after they are exposed to harmful algae, or after they've ingested it. Symptoms include excessive drooling, vomiting or diarrhea, foaming at the mouth, jaundice or an enlarged liver, blood in their urine or dark urine, stumbling, loss of appetite, abdominal tenderness, progression of muscle twitches or respiratory paralysis.

Humans may experience a rash, irritation, swelling, sores, a fever, headache, eye irritation, or gastrointestinal, neurological, ear or respiratory issues.

"People should not drink or ingest water directly from Central Texas lakes or from any springs or creeks," the city said. "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."

If a person or pet has sudden, unexplained illness after swimming or signs of poisoning, call a medical provider or veterinarian right away or the Texas Poison Control Center at 800-222-1222. You may also report the suspected exposure to harmful algae to the city of Austin using English or Spanish forms available at AustinTexas.gov/Algae.

This article originally appeared on Austin American-Statesman: Toxin harmful to dogs found in Austin's Barking Springs water sample