Initial findings of an investigation launched after several dogs were believed to be chemically burned revealed the animals' injuries were caused not by an abuser but by the blistering sun.
Community outcry after NBC4 first reported on Fergus, a golden retriever found with severe burns along its spine, sparked an investigation that led police to more cases of injured dogs.
A $50,000 reward was also offered to help find the person responsible for what was believed to be acid attacks.
But a report by the Los Angeles County Sheriff's Department concluded animal cruelty was not to blame in recent cases where dogs were brought into shelters with seared flesh.
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"Both animal forensic experts and veterinary experts formed the opinion the dogs were not intentionally burnt, but suffering from burns caused by the sun, solar thermal necrosis," the LAC Sheriff's Department said in a statement.
The investigation examined a total of 10 cases, with only one dog, found in 2012, injured by chemical burns, the report said.
But the revelation was not received well by some who came to aid the animals after the so-called attacks.
Dr. Alan Schulman, who treated Fergus when he was brought in with severe burns, said he stands by his original diagnosis that the golden retriever was chemically burned by acid.
"I'm flat-out stunned," he said of the findings.
"It's ridiculous," said a rescuer who took in a dog named Taco last month. "His skin was literally peeling off his back and it pretty much went clear down to the bone... I don't know what it is, but it's not the sun's fault."
The $50,000 reward remains in place while the LACSD continues its investigation.