Bovine spongiform encephalopathy (BSE), also known as "mad cow disease," is a slow, progressive, fatal disease of the nervous system of cattle. It typically occurs in cattle 5 years of age or older. BSE has been found in cattle native to the USA and Canada. Scientific evidence suggests BSE is associated with a rare human disease called variant Creutzfeldt-Jakob disease (vCJD).WHAT CAUSES BSE AND HOW DO CATTLE BECOME INFECTED?Diagnosis of BSE is difficult because there are no live animal tests. PREVENTING transmission of the BSE agent is the ONLY safeguard available because there are no treatments and no vaccines available.
The causative agent of BSE is believed to be an unconventional transmissible prion protein. These proteins accumulate in brain tissue, causing changes in behavior that progress to dementia and death.WHAT IS THE USA DOING TO PREVENT BSE TRANSMISSION IN CATTLE?It is widely believed cattle become infected by eating feed contaminated with BSE-infective material. The suspected source of infectivity is rendered proteins derived from ruminants.
The USDA regulates the importation of animals from countries with BSE, and actively tests cattle for the disease. FDA's "Mammalian Protein Ban" in place since 1997 prevents livestock producers from feeding prohibited materials to ruminants.Prohibited materials are protein-based materials, including meat and bone meal, derived from ruminants.
Ruminant animals are any animals with a four-chambered stomach including, but not limited to, cattle, sheep, goats, buffalo, elk, and deer.