Officials previously said that the California Holstein with mad cow disease had shown no signs of the illness. Now they say it was lame and had taken to lying down, the AP reports. It was "humanely euthanized after it developed lameness and became recumbent," according to the USDA. Meanwhile, a congressman's office had said the cow was five years old; now the USDA says it was 10 years and seven months old. Cows older than 2½ face a higher risk of the disease, also known as BSE. Officials continue to say the food supply is not at risk; the cow was never meant for the meat market.