Updated: July 21, 2017

Agriculture officials say a rarely seen form of mad cow disease has been found in Alabama.

A statement from state Agriculture Commissioner John McMillan says the atypical form of a bovine disease was confirmed in an 11-year-old beef cow. The U.S. Agriculture Department says this is only the fifth case of the atypical form of the disease being confirmed in the United States.

McMillan says the animal was discovered during routine screening at a livestock market. The cow wasn't slaughtered and its meat didn't enter the food chain.

Mad cow disease can spread from by-products of cud-chewing animals being used in feed, but the state says that's not what happened. The state is calling the discovery a "rare and spontaneous" case of the disease, which can occur in older animals.