Bovine Spongiform Encephalopathy (BSE)

What is Bovine Spongiform Encephalopathy (BSE)?

Bovine Spongiform Encephalopathy (BSE) is a slowly progressive, degenerative disease affecting the central nervous system of adult cattle. BSE is fatal in cattle that become infected. BSE is commonly called Mad Cow Disease. BSE is named because of the spongy appearance of the brain tissue of infected cattle examined under a microscope.

What causes BSE?

The exact cause of BSE is not known. However, it is generally accepted by the scientific community that the likely cause of BSE is abnormal, infectious forms of a type of protein, called prions, normally found in animals. In cattle with BSE, these abnormal prions initially occur in the small intestines and tonsils and are found in central nervous tissues, such as the brain and spinal cord, as well as other tissues of infected animals experiencing later stages of the disease.

Does BSE affect people?

Other species of animals can have diseases similar to the BSE found in cattle. The best-known occurrence is in sheep, which fall victim to a disease called scrapie. Similar versions also occur in mice, cats, deer, elk and mink. The Spongiform Encephalopathy diseases are not easily transmitted between species. A disease similar to BSE, called Creutzfeldt-Jacob Disease (CJD), is found in humans. This disease is very rare; the historic rate of occurrence is about 1 case for every million people. Although not scientifically proven, there is strong epidemiologic and laboratory data linking a rare, degenerative, fatal brain disorder in humans called variant Creutzfeldt-Jakob Disease (vCJD) to the consumption of BSE-contaminated product. As of June 2006, there have been 192 confirmed and probable cases of vCJD worldwide among the hundreds of thousands of people that may have consumed BSE-contaminated beef products. The vast majority of these cases have occurred in Britain, where BSE was first observed and the prevalence of infected cattle has been quite high. The one reported case of vCJD in the United States was in a young woman who contracted the disease while residing in Britain and developed symptoms after moving to the U.S.

How long can BSE be in an animal before it shows signs of the disease?

The incubation period (the time from when an animal becomes infected until it first shows disease signs) is from 30 months to eight years with only a few rare exceptions in younger animals. Following the onset of clinical signs, the animal's condition deteriorates rapidly. This process usually takes from two weeks to six months. Most cases in Great Britain occurred in dairy cows between three and six years of age.

What has been done to make sure BSE does not get into cattle in the United States?

The U.S. Department of Agriculture (USDA) is responsible for making sure that BSE does not get into the United States. The USDA program includes regulations controlling the entry of cattle and ingredients derived from cattle into the United States. USDA also manages an extensive program for testing cattle in the United States to confirm the absence of BSE.

Is there a concern about BSE and cosmetic products?

Current scientifically-based programs in Europe and the United States are designed to protect consumers of cosmetic products. Link to FDA programs to protect U.S. consumers:

More Information

More information about the regulations controlling entry of cattle and cattle-derived ingredients into the United States: USDA BSE Programs: USDA BSE Rules Being Strictly Enforced: In addition, the FDA has established regulations and monitoring programs to make sure that BSE-infected cattle materials do not enter the marketplace. This includes direct controls, such as prohibition of certain materials from use in FDA-regulated products, as well as record-keeping requirements. More information about the FDA programs: The European Union has implemented tight controls and monitoring to ensure that the incidence of new cases in cattle is controlled. Monthly reports of the incidence of new cases are released to the public. These reports clearly demonstrate the incidence of BSE in the European Union is steadily declining and has reached a very low level. The UK remains the country with the highest number of new cases. Link to monthly/yearly monitoring reports: Link to summary report: