AUSTIN – Mia Mineghino took her dog, Koda, nearly every morning to Red Bud Isle, a popular off-leash dog park on Lady Bird Lake, now closed because of a deadly algae threat.

The last time Mineghino and Koda visited was July 7, when the pair made it to the park before sunrise. After Koda swam and played in the lake, he hopped into Mineghino's car, with the windows rolled down. When Mineghino looked back at her dog, a German shepherd-Rhodesian ridgeback mix she'd had for two years, she said he didn't look OK.

As they pulled onto her street, he lost his balance and fell, unable to use his legs. She screamed for help and firefighters at a station next door helped her get Koda back in the car to take him to a veterinary clinic.

"I could hear him moving his legs and having a hard time breathing," Mineghino told the American-Statesman by phone Thursday, in tears. "Two minutes into the drive, I stopped hearing him move. I was just screaming in the car, 'You are going to be OK. I love you. We are almost there.’”

When they arrived at the vet, staffers took Koda in back. Ten minutes later, they came back and said Koda was brain dead.

"I laid with him for about an hour. They gave him the euthanasia, and that was that," Mineghino said. 

Koda is one of three dogs that have died in recent weeks after swimming at Red Bud Isle, something the city now attributes to the possible presence of a neurotoxin in the water at Lady Bird Lake, produced by a kind of blue-green algae that has been spotted there.

The type of algae, which has never before been reported in Austin, has accumulated in large clumps at Red Bud Isle, covering about 40% of the surface of the water there. Further testing is being done to determine toxicity and any risk to humans. The city has not verified that the dogs' deaths were definitively connected to the algae, but officials on Wednesday said they have no reason not to believe the pet owners' accounts.

In the meantime, Red Bud Isle has been closed to the public, and pet owners are urged not to let their dogs in the water at Lady Bird Lake or surrounding creeks and streams.

READ MORE: What you need to know about the toxic ‘algae’ growing in Austin’s Lady Bird Lake

Claire Saccardi, the second of three women to lose her dog after swimming at Red Bud Isle, said the city's response is too little, too late.

Saccardi's dog, Harper, died Aug. 1. She notified the city two days later, on Saturday, after reading about blue-green algae toxicity on the internet. Signs weren't posted at Red Bud Isle warning pet owners until Monday afternoon.

"I am just concerned because I think this was handled too slow," Saccardi said Thursday. "I am worried that people still don’t know or they don’t understand how serious it is. … If I had known, we would have never gone. I loved Harper with my whole heart, and we would have never gone."

The city said it did not put information about the dogs dying in the first advisory it sent out Sunday because it had not been able to confirm at the time that their deaths were related to the toxin in the algae, which it still cannot say definitively.

“The animal was destroyed before we had the opportunity to have a toxicology screening," city spokesman David Green said Monday. "To my knowledge, I don’t think that test was done.”

After Saccardi lost her dog, she said she went to the lake Saturday — before the city put out an alert — to warn people. She described the scene at Red Bud Isle as a "horror show."

"There were hundreds of people at the park," she said. "I tried to tell as many as them as possible what happened. I probably looked like a crazy person."

That same day, Brittany Stanton would take her dog, Ollie, to Red Bud Isle to kayak. Ollie would die that same evening.

"It’s not fair, and it’s not okay," Stanton wrote in a lengthy post on Facebook that went viral. "Word needs to be spread about this incredibly devastating risk."

Saccardi's and Stanton's accounts of what happened to their dogs mirror Mineghino's story almost exactly. Their dogs got in the water. Shortly after, they noticed the dogs lost their balance and couldn't stand.  Within the hour, they were dead.

"It’s just heartbreaking," Mineghino said. "We thought that this was the best dog-friendly city, and now our best friends have died here, and it is hard to not feel mad about it."

Saccardi said she wanted to emphasize that she gave Harper, her 4-year-old golden retriever, a bath after they got back from the lake, something the city has recommended pet owners do if they accidentally get in the water. That didn't keep her dog from getting sick and dying.

City officials say only Lady Bird Lake is affected by the algae but that it could move downstream, affecting other waterways.

"I wouldn’t go in the water for the next several months, even when they say the water is fine," Mineghino said.