See if this works for you. The following was adapted from
http://www.aphis.usda.gov/lpa/issues/bs ... rview.html
Bovine Spongiform Encephalopathy (BSE)
Bovine spongiform encephalopathy (BOW-vine SPONGE-uh-form en-SEP-uh-LAW-path-ee) (BSE), widely known as "mad cow disease," is a degenerative disease affecting the brain and spinal column of cattle. Worldwide there have been more than 180,000 cases since the disease was first diagnosed in 1986 in Great Britain. BSE has had a large impact on the livestock industry in the United Kingdom. The disease has also been found across Europe in Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, Liechtenstein, the Netherlands, Northern Ireland, Poland, Portugal, Slovakia, Slovenia, Spain and Switzerland as well as in Israel and Japan. However, world wide, over 95% of all BSE cases have occurred in the United Kingdom. BSE is not known to exist in the United States.
BSE belongs to the family of diseases known as the transmissible spongiform encephalopathies (TSE's). These diseases are caused by an unknown agent. They share the following common characteristics
a. a prolonged incubation period of months or years;
b. Progressive mental deterioration leading to death.
c. Under a microscope, the BSE affected brain tissue looks like a sheep disease called scrapie;
d. The only affected organs are the brain and spinal column nervous system;
e. The animalâ€™s immune system is not triggered by the infection.
Similar Diseases of Humans and Other Animals
TSE's are all caused by similar but unknown agents acting only in the brain. TSE's include scrapie (which affects sheep and goats), transmissible mink encephalopathy, feline spongiform encephalopathy, chronic wasting disease of deer and elk, and in humans, kuru, Classical Creutzfeld-Jakob Disease (CJD), Gerstmann- Straussler syndrome, fatal familial insomnia, and vCJD.
Clinical Signs of BSE in Cattle
Affected animals may have â€œmood swings,â€ such as nervousness or aggression; abnormal posture; loss of coordination and difficulty in standing up; decreased milk production; or loss of muscle mass despite continued appetite. There is no treatment and affected cattle die.
The incubation period ranges from 2 to 8 years. Following the onset of clinical signs, the animal's condition deteriorates until it dies or is destroyed. This usually takes from 2 weeks to 6 months. Most cases in Great Britain have occurred in dairy cows between 3 and 6 years of age.
The Cause of BSE
The cause of BSE as well as other TSE's is yet to be completely understood. Three main theories on the nature of the agent have been proposed:
Â· An unconventional virus.
Â· A prion or abnormal protein, lacking nucleic acid, capable of causing normal prion protein in the host to change and form more abnormal protein.
Â· A virino or "incomplete" virus composed of naked nucleic acid protected by a host protein.
The BSE agent (1) is smaller than most virus particles and is highly resistant to heat, ultraviolet light, radiation, and common disinfectants that normally kill viruses or bacteria; (2) causes no immune response in the host; and (3) has not been observed under a microscope.
How BSE Is Diagnosed
There is no test to detect the disease in a live animal. Currently there are two laboratory methods to confirm a diagnosis of BSE: 1. Microscopic examination of the brain tissue to identify changes; 2. Techniques to detect the resistant form of the prion.
Can the USDA guarantee that BSE will never occur in the United States?
There are still a number of unknowns regarding the origin and transmission of BSE. Given these scientific uncertainties, we cannot assure zero risk from BSE. However, we can and will continue to monitor new scientific findings and world events and adjust our regulations and policies to keep the risk of BSE infecting the national herd as low as
BSE Has NOT Been Found in the United States
No cases of BSE have been confirmed in the U.S.A. since we started testing for it in 1990.
What About Other Animal TSE's in the US?
These TSE's HAVE been found in the United States: Scrapie in sheep and goats, transmissible mink encephalopathy, and chronic wasting disease of deer and elk.
The Cause of BSE in Great Britain
The study of the epidemic suggests that BSE in Great Britain came from one common source involving animal feed containing contaminated meat and bone meal. The cause is suspected to be from either scrapie- affected sheep or cattle with a previously unidentified TSE. Changes in meat processing in the late 70'sâ€”early 1980's may have allowed the agent's survival in meat and bone meal.
For more information about BSE in the United Kingdom, please visit the Department for Environment, Food and Rural Affairs (formerly the Ministry of Agriculture, Fisheries and Food, UK) web site.
Countries Other Than the United Kingdom With Confirmed Cases of BSE
In native cattle: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Ireland, Israel, Italy, Japan, Luxembourg, Liechtenstein, the Netherlands, Northern Ireland, Poland, Portugal, Slovakia, Slovenia, Spain and Switzerland. While there is a decline in the number of cases of BSE in the United Kingdom, confirmed cases of BSE have risen in other European countries.
Oman, the Falkland Islands, Canada, and the Azores have detected BSE in cattle imports from other countries known to have BSE.
On May 20, 2003, Canada had a cow test positive for BSE. Previously, there had been one case of BSE in a single cow in Canada in 1993. It had been imported from Great Britain and was dealt with by destroying the affected cow and all its herdmates, as well as other cattle determined to be a risk by animal health officials in Canada.
For more information, please see Office International des Epizooties.
Transmission of BSE
There is no reason to think that BSE spreads by contact between unrelated adult cattle or from cattle to other species. There may be a low level of transmission from cow to calf. British research shows that approximately 9-percent of offspring from BSE-affected cows will carry the disease compared to calves born to cows without BSE. The study did not determine if this was the result of genetics or true transmission. The research did point out that at this level if maternal transmission does occur, it alone will not sustain the epidemic (Wilesmith et al. 1997).
A recently published study found no disease transmission to embryos collected from cows with BSE. (Wrethall et. al., 2001).
What is the USDA policy in regard to BSE, and what actions has USDA taken?
The USDA policy has been to actively look for the disease and try to prevent it. The USDAâ€™s Animal and Plant Health Inspection Service (APHIS) has taken measures in surveillance, prevention, education, and response. Import restrictions started in 1989, and surveillance began in 1990. The USDA continually monitors all events and research findings regarding TSEâ€™s, as new information and knowledge may lead to changes in prevention measures. APHIS has also created a TSE Working Group to analyze risks of BSE to the United States, inform the public about the TSE's, and provide references for responding to questions about TSE's.
Is APHIS working with other agencies and groups to coordinate efforts?
Yes. APHIS has shared information and met with State and Federal agencies, including the Centers for Disease Control and Prevention (CDC), the Food and Drug Administration (FDA), the Food Safety and Inspection Service (FSIS), the National Institutes of Health (NIH), and stakeholders to assure we are taking the proper actions in response to changing knowledge and information concerning BSE.
Is BSE a notifiable disease in the United States?
Yes. Veterinarians must report the disease and animals that appear to be mentally affected.
What types of BSE surveillance are we doing?
USDA-APHIS, in cooperation with USDA-FSIS and State diagnostic laboratories, has a surveillance program which targets the cattle population where the disease would most likely be found if it were to occur.
Â· APHIS educates veterinarians, laboratory diagnosticians, industry and producers on the signs of BSE.
Â· APHIS monitors the remaining cattle imported from countries known to have BSE or have high risk factors for BSE.
Â· Since 1990, more than 60 diagnostic laboratories across the United States and all the USDA's laboratories continue to examine hundreds of cattle brains each year submitted from cattle showing signs of the disease during or before processing. FSIS performs inspections at all USDA processing plants, and inspectors are alert for brain type disorders. Any brain affected animals are condemned and tested. Public health laboratories also submit samples that have tested negative for rabies.
Â· The network of private veterinarians that refers unusual cases to vet schools or State laboratories around the United States provides an extensive informal but important surveillance system.
Â· USDA has trained more than 250 State and Federal field veterinarians located throughout the United States in the recognition and diagnosis of foreign animal diseases, including BSE.
Â· Veterinary pathologists at zoos in the United States routinely conduct examinations on the brains of dead zoo animals exhibiting similar signs since similar diseases have been found in seven species of exotic cattle at zoos in England.
What type of adult cattle do we test?
1. Neurologically ill cattle found on farm
2. Neurologically ill cattle at veterinary labs or hospitals
3. Rabies-negative cattle
4. Cattle condemned at processing for neurologic disease
5. Cattle that cannot stand (downers/fallen stock)
6. Adult cattle dying on farms from an unknown cause
Has the United States imported cattle from the United Kingdom?
Yes. Between 1981 and 1989, 334 cattle were imported from the United Kingdom and 162 from the Republic of Ireland. These imports have been traced, and there are only 3 cattle still alive in the United States (as of November 2001). These animals have been quarantined since April 1996. APHIS is trying to buy these cattle for testing. In July 1989, the import of live cattle from the United Kingdom was banned.
In addition, 5 head of cattle imported from other countries in Europe in 1996 remain under quarantine. APHIS, in cooperation with the States and industry, continues to buy these animals for testing. No evidence of BSE has been found in any of these imported animals.
Does the United States still permit the feeding of ruminant protein to ruminants?
No. On August 4, 1997, the Food and Drug Administration (FDA) established regulations that prohibit the feeding of most mammalian proteins to ruminants.
What proactive initiatives are underway to educate farmers, veterinarians, extension agents, etc.?
An important part of the USDA's active surveillance program is the training of veterinarians in the signs, diagnosis and sampling for BSE. Videotapes of cattle showing clinical signs of BSE have been distributed to veterinarians in Federal and State governments, laboratories, and pathology departments of veterinary colleges. Microscope slides showing typical BSE lesions have been distributed to the laboratories, and Federal Foreign Animal Disease (FAD) diagnosticians have trained in Great Britain in BSE recognition. BSE fact sheets, risk assessments, and reviews have also been sent to State and Federal veterinarians, private practitioners, other industries, and to producers. In addition, APHIS personnel have given numerous presentations to various animal health groups. Finally, over 250 Federal and State veterinarians throughout the US have been trained in the recognition of FAD's including BSE.
What measures has USDA-APHIS taken to prevent the introduction of BSE?
In 1989, APHIS banned the import of all cattle and restricted the import of certain cattle products from the United Kingdom and other countries where BSE was diagnosed.
On December 6, 1991, APHIS restricted the import of cattle meat and banned most byproducts of cattle origin from countries known to have BSE (56 Federal Register [FR] 63868 and 63869). Prior to this, the products were prohibited by not issuing permits.
Certain products cannot be imported into the United States, except under special permit for scientific, educational or research purposes, or under special conditions to be used in cosmetics. These products include serum, glands, collagen, etc.
As of December 12, 1997, APHIS has prohibited the import of live cattle and most cattle products from all of Europe. The restrictions applied to Albania, Austria, Bosnia-Herzegovina, Bulgaria, Croatia, Czech Republic, Denmark, Federal Republic of Yugoslavia, Finland, Germany, Greece, Hungary, Italy, the former Yugoslavian republic of Macedonia, Norway, Poland, Romania, Slovak Republic, Slovenia, Spain, and Sweden. These actions were in addition to those already in place regarding countries that had reported BSE in native cattle.
This action was taken in 1997 because the Netherlands, Belgium, and Luxembourg have reported their first cases of BSE in native-born cattle. There is evidence that European countries may have had high BSE risk factors for several years and less-than-adequate surveillance.
An interim rule was published and the comment period closed on March 9, 1998. Criteria to assess the risk factors were developed in accordance with the standards adopted by the Office of International Epizootics (OIE).
Have we allowed the importation of cattle semen and embryos from BSE-affected countries?
Yes. BSE has never been detected in embryos, semen, or reproductive tissues of BSE-affected cows and bulls. Embryo transfer experiments have been completed in cattle. This recently published study found that the disease is not transmitted via embryos collected from cows with BSE.
Import protocols exceed the recommendation of the Office of International Epizootics (OIE). All bulls producing semen for export to the United States are required to meet all 5 of the following conditions:
1. The semen donor has not been on premises where BSE has occurred within 5 years of the date of embryo or semen collection;
2. The semen donor is not affected with BSE;
3. No progeny of the semen donor is affected with BSE;
4. The parents of the semen donor are not affected with BSE; and
5. The semen donor has not been fed ruminant-derived protein.
What actions are taken at USDA-inspected slaughter establishments to ensure that cattle with brain diseases would not enter the human food supply?
All cattle sent for processing in the United States are inspected by FSIS for signs of brain impairment. Any animals with signs during this inspection are condemned, and the meat is not permitted for use as human food. The brains from these animals are sent to USDA's National Veterinary Services Laboratories for analysis.
Does USDA have a response plan in the event a case of BSE or TSE is diagnosed in US cattle?
Yes. In 1990, APHIS developed a plan to respond to a confirmation of BSE in the US In August 1996, a joint APHIS-FSIS working group updated this BSE response plan. The purpose of the plan is to provide a step-by-step plan of action in the event that a case of BSE is detected in the United States. The plan outlines those events that should take place, including identifying suspect animals, confirmation, the investigation, animal and herd disposal, and informing the public. The plan has been shared with other government agencies that have developed their own plans to coordinate with those of USDA.