Spongiform encephalopathy, or, as it is popularly called, mad cow disease - a disease that affects cattle. The disease manifests itself with signs of aggression, paralysis of the extremities, photophobia, which is quite similar to the usual rabies of mammals. There is an opinion that mad cow disease is dangerous for humans. Cow encephalopathy is common in England, but several cases have been reported in other European countries.
Causative agent of infection
Until now, scientists around the world can not figure out what really causes mad cow disease. Numerous studies do not confirm the viral or bacterial nature of this
cattle disease. Most researchers are inclined to think that an abnormal prion protein, which has a violation in its structure, plays a huge role in the development of the disease.
It is also well known that the causative agent of mad cow disease can withstand boiling for three hours, is not at all “afraid” of disinfection and can be stored for years in a dried state or at sub-zero temperatures.
The causative agent causes degenerative changes in the brain, as a result of which it is destroyed and turns into something resembling a sponge. Hence the disease got 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 with scrapie. It is known that this disease in
small cattle causes profound changes in the central nervous system, leading to paralysis and exhaustion.
As in the case of spongiform encephalopathy of cows, the nature of the causative agent of scrapie is not fully understood.
Transmission of the causative agent of infection through air, or aerogenically, has not been confirmed.
Mad Cow Disease: Symptoms
The incubation, or latent, period of the disease can last from a year to several years. The following symptoms are characteristic of spongiform encephalopathy:
- shaky gait;
- perversion or lack of appetite, refusal of food;
- cramps
- paralysis of the limbs;
- progressive exhaustion;
- decrease in productivity.
Mad cow disease can also be violent. In this case, during periods of seizures, the animal begins to break off the leash, roar loudly, rush to obstacles, dig the earth with horns. Aggression can be strongly expressed, it is especially pronounced when the animal enters a limited or narrow space.
How is mad cow disease diagnosed?
The diagnosis is initially made according to clinical symptoms and epizootological data. The brain of fallen animals is sent to the veterinary laboratory.
In turn, the main work of veterinary laboratory assistants is to detect changes in the material sent that are characteristic of bovine spongiform encephalopathy. The treatment has not been developed.
Danger to humans
Most scientists are inclined to believe that people who eat the meat of cows infected with spongiform encephalopathy are at risk. Even if today they have no signs of illness or degenerative changes in the brain, no one can guarantee that in 20-30 years the disease will not make itself felt.