In the early 1986, cattle especially cows began dying in the Great Britain due to a mysterious illness. The animals greatly observed weight loss, became aggressive, were found unsteady on their hooves and moreover they lacked coordination. These group of symptoms were dangerous for the survival of the cattle and ultimately known as The Mad Cow Disease . The affected animal eventually died from it.
Exactly 4 years later a similar disease surfaced in humans in Great Britain. Now, humans were showing similar signs and symptoms as cattle suffering from Mad Cow Disease. Several hundred young people died due to this dangerous brain disorder. The symptoms exhibited include dementia, weakened muscles and loss of ability to body balance. At that time, investigative agencies and health officials concluded that this Mad Cow Disease resulted from eating beef that has been received and processed from cattle that suffered from Mad Cow Disease. So, the disease was transmitted from cattle to humans.
Later on, it was discovered that the disease can be transmitted from animals to animals also. And the causative agent was a mystery until the discovery that they are neither bacteria nor viruses but a special type of infectious proteinaceous particles known as prions.
These prions cause spongiform of the brains in the infected individuals. They are responsible for neurological degenerative diseases that are transmissible from one to another.