The first case of BSE, or Mad Cow Disease was discovered on 12/23/03 in the US. The purpose of this Q & A is to educate about the disease process in cattle. For human health and current political issues about BSE, please visit with your local health care provider or refer to local/national/Internet news sources.
What does BSE stand for?
BSE (at least in terms of veterinary medicine) stands for Bovine Spongiform Encephalopathy.
Bovine = Of, relating to, or resembling a ruminant mammal of the genus Bos, such as an ox, cow, or buffalo.
Spongiform = Resembling a sponge in appearance or texture; spongy
Encephalopathy = Any of various diseases of the brain.
Why is is called "Mad Cow" disease?
BSE is a relatively new disease, first diagnosed in Great Britain in 1986. The common name of "Mad Cow" is probably due to the loss of motor control, dementia and behavioral changes seen in the late stages of this disease.
What causes BSE?
BSE is an interesting disease from a medical standpoint because of the causative agent, prions (pronounced pree-ons). Which leads the to the question...
What is are prions?!
A prion is an infectious protein that are similar to a virus, but not a typical virus. Unlike viruses, prions aren't alive, so they can't be killed with the usual disinfectants. The body does not mount a typical viral immune attack against prions, either. Prion proteins can be denatured, but only at extremely high temperatures or with very strong chemicals, either way, not consistent with animal life so these are not treatment options. Diseases caused by prions are referred to as TSEs -- Transmissible Spongiform Encephalopathies.
How do prions infect cows?
The most common mode of infection is via feeding cows contaminated feed -- feed that contains animal proteins (from sheep or cows). Researchers are still studying modes of transmission and if heredity/genetics plays a role in an individual animals susceptibility to, or protection from, acquiring this disease.
How is BSE diagnosed?
BSE is suspected in animals that exhibit neurological problems such as: staggering, general loss of motor control, dementia/behavioral changes, increased startle reflex, weakness, weight loss, and decreased milk production. BSE is diagnosed by examining the brain tissue of the deceased animal and finding characteristic "moth eaten" appearance of the brain tissue.
How long does it take for BSE to develop in cattle?
BSE has a long incubation period, meaning that it can take months or years to show clinical signs. Once a cow starts showing signs, it is often terminal within 3 months.*
* (Merck Manual, 8th ed. p 898)
Is BSE always a fatal disease?
We eat lots of deer, elk and other wild game. Do they carry BSE?
No, but wild game have their own "version" of TSE disease, Chronic Wasting Disease (CWD), also a prion disease.
Can humans catch Mad Cow disease?
Technically, no, since this is a bovine disease. However, there is a human version, and it is called Creutzfeld-Jacob Disease, that has been linked to eating infected cow meat. This is an area of intense research at the present time, searching for clues about diagnosis, transmission and risk factors.
Where can I learn more about the human form of this disease and staying healthy?
What You Need to Know About Bovine Spongiform Encephalopathy
From Chemistry Guide, Anne Marie Helmenstine, Ph.D.
Mad Cow Disease - What is Safe to Feed Your Kids
From Pediatrics Guide, Vincent Iannelli, M.D.
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