PITTSBURGH -- A local woman said her dog died from eating tainted dog treats.

On Wednesday, Wal-Mart announced two brands of dog treats sold at its stores contained the chemical melamine.

Those products were pulled from store shelves in July, but have not been recalled.

Jodi Zeremski said her Chihuahua, Taco, never had health problems until she bought chicken jerky dog treats from Wal-Mart in early July.

Soon after eating the treats, Taco reportedly became ill and had to be put down.

A veterinarian said he died of kidney failure.

"Those were the only treats we bought. That was the only other thing that dog ate,” Zeremski said.

Gretchen Fieser, of the Western Pennsylvania Humane Society, said, "Melamine typically causes kidney failure. Some of the signs of kidney failure are depression. They can become very lethargic, not having very much energy, lying around and vomiting."

Wal-Mart has released a statement: "We will continue to work with the supplier to assure that the highest safety standards are met. Our thoughts are with anyone whose pet may have become ill."