The word BSE is short but it stands for a disease with a long name, bovine spongiform encephalopathy. Bovine means that the disease affects cows, spongiform refers to the way the brain from a sick cow looks spongy under a microscope, and encephalopathy indicates that it is a disease of the brain.BSE is commonly called “mad cow disease.”. sick cow has trouble walking and getting up. A sick cow may also act very nervous or violent, which is why BSE is often called “mad cow disease.”. It usually takes four to six years from the time a cow is infected with the abnormal prion to when it first shows symptoms of BSE.