An 11-year old cow in Alabama is the fifth case of Bovine Spongiform Encephalopathy (BSE) to be found in the United States since 2003, the U.S. Department of Agriculture announced late on Tuesday.

The non-scientific name for BSE is mad cow disease, a prion disease that reached epidemic levels in Great Britain in the late 1980s and early 1990s.

Like the previous U.S. cases, the Alabama animal was ruled to be an atypical case of BSE.  Atypical is rare, and occurs in cattle older than 8 years, arising spontaneously in the population.

Also like the others, USDA says the Alabama cow was not slaughtered, never entered the food supply and presents no risk to human health in the United States or anywhere else.

The single animal was found positive for atypical (L-type) BSE, according to the  USDA Animal and Plant Health Inspection Service’s (APHIS) National Veterinary Services Laboratories (NVSL).

The cow was observed showing  clinical signs of BSE during routine surveillance at an Alabama livestock market. APHIS and Alabama veterinary officials are gathering more information on the case.

There are two types of BSE, classical and atypical. Classical BSE, which is associated with variant Creutzfeldt-Jakob disease (vCJD) in people, caused the British epidemic.

Meat-and-bone meal containing protein from rendered infected cattle caused Europe’s Mad Cow outbreak. BSE is not contagious.

In the U.S. regulations have prohibited the inclusion of mammalian protein in feed for cattle and other ruminants since 1997 and have also prohibited high risk tissue materials in all animal feed since 2009.

Only the first cow discovered with BSE in the United States was a classic case. It had been imported from Canada to Washington State. The latest case in Alabama is not expected to rattle cattle markets.

The United States has a “negligible risk” rating for BSE from the World Organization for Animal Health (OIE). OIE guidelines for determining status say that atypical BSE cases do not impact official BSE risk status recognition as this form of the disease is believed to occur spontaneously in all cattle populations at a very low rate.

The  finding of an atypical case will not change the negligible risk status of the United States, and should not lead to any trade issues, according to USDA.

“The United States has a longstanding system of interlocking safeguards against BSE that protects public and animal health in the United States, the most important of which is the removal of specified risk materials – or the parts of an animal that would contain BSE should an animal have the disease – from all animals presented for slaughter,” USDA’s statement said.