RALEIGH, N.C. — The U.S. Food & Drug Administration said a pet food company improperly tested, or failed to test, tainted dog food that was distributed throughout the southeast United States last year.

Diamond Pet Foods recalled about 1 million pounds of dog food in December after dozens of dogs became ill or died after eating the food.

The FDA's report, which is expected to be officially released this week, carries no penalties for the company.

Dr. Mary Ann McBride, a veterinarian with the North Carolina Department of Agriculture, said the state came to the same conclusion that the FDA did: that the corn contracted a deadly fungus, which in turn poisoned some batches of dog food.

But McBride said is impossible to test every kernel of corn.

"Diamond Dog is a well-respected company," she said. "I have no concerns about their products. They unfortunately got a bad batch of corn."

Still, the company wants to make sure it is doing everything it can to try to prevent it from happening again by doing more testing.

But for affected dog owners an understanding of the problem comes too late.

"Certainly, (we're) just kind of disappointed that it happened and that we were in the fray of the, or in the aftermath of that mistake," said Dr. Gentry Matthews, whose dogs died after eating the food.