Spongiform encephalopathy, or mad cow disease

Spongiform encephalopathy, or, as it is called in the people, cow rabies is a disease that affects cattle. The disease manifests itself as signs of aggression, paralysis of the limbs, photophobia, which is quite similar to the usual rabies of mammals. There is an opinion that cow rabies is dangerous for humans. Encephalopathy of cows is common in England, but several cases of the disease have been documented in other European countries.

Infectious agent

Until now, scientists around the world can not figure out what actually causes mad cow disease. Numerous studies in no way confirm the viral or bacterial nature of this disease of cattle. The majority of researchers are inclined to think that in the development of the disease an enormous role is played by abnormal prion protein, which has a violation in its structure.

It is also well known that the causative agent of cow rabies can withstand boiling for three hours, is not at all "afraid" of disinfection, and can persist for years in the dried state or at subzero temperatures.

The causative agent causes degenerative changes in the brain, as a result of which it collapses and turns into something resembling a sponge. Hence the disease and received its name "spongiform encephalopathy".

What is the source of infection?

Scientists came to the conclusion that the infection of cows occurs as a result of feeding them meat-and-bone meal obtained from sheep, sick scrapie. It is known that this disease in small cattle causes profound changes in the central nervous system, leads to paralysis and exhaustion.

Just like in the case of spongiform encephalopathy of cows, the nature of the scrape pathogen is not fully understood.

The transmission of an infectious agent through the air, or by aerogenic means, has not been confirmed.

Mad Cow Fever: Signs

Incubation, or hidden, period of the disease can last from a year to several years. For spongiform encephalopathy, the following symptoms are typical:

• Shaky walk;
• Perversion or lack of appetite, refusal to feed;
• Convulsions;
• Paralysis of the limbs;
• Progressive exhaustion;
• Decrease in productivity.

Cow rabies can also manifest itself in a violent form. In this case, during periods of seizures, the animal starts to break off from the leash, loudly roar, rush to obstacles, dig the ground with horns. It can be strongly pronounced aggressiveness, especially brightly manifested when the animal hits a limited or narrow space.

How is "mad cow disease" diagnosed?

The diagnosis is first made according to clinical symptoms and epizootic data. The veterinary laboratory sends the brain of the fallen animals.

In turn, the main work of veterinary laboratory assistants is to detect the changes in the sent material, characteristic for spongiform encephalopathy of cows. Treatment is not developed.

Danger to humans

Most scientists are inclined to believe that people who ingested meat from cows infected with spongiform encephalopathy are at risk. Even if today they have no signs of disease or degenerative changes in the brain, no one guarantees that in 20-30 years the disease will not make itself felt.