Mad cow disease started spreading among British herds in the mid-1970s. The disease began to peak in 1993 with about 1,000 cases a week. By 1996, variant Creutzfeldt-Jakob Disease or vCJD was detected in humans and was linked to the epidemic. But did you know that a virus or bacteria didn’t spread it?
Mad Cow Disease does not spread by a virus or bacteria. It spreads due to a misfolded protein called a prion. When the prion gets in contact with normal proteins of the same type, this will cause the normal proteins to misfold and cause a reaction.
What is Mad Cow Disease?
Mad Cow Disease or Bovine Spongiform Encephalopathy (BSE) is an incurable neurodegenerative disease found in cattle. BSE is known to be caused by a misfolded protein called a prion. Cattle infected with the disease are believed to be fed with a meat-and-bone meal (MBM) which contains the remains of cattle or other animals that spontaneously developed the disease.
Research shows that the first probable infection of BSE happened in the 70s. However, the disease was only identified in 1986. The BSE epizootic in the United Kingdom reached an all-time high in January 1993, with almost 1,000 new cases every week. (Source: CDC)
What Are the Signs of Mad Cow Disease?
Due to the long incubation period, the signs of Mad Cow Disease are not seen immediately. However, some cows present with an abnormal gait, changes in behavior, hyper-responsiveness to certain stimuli, or tremors.
Hindlimb ataxia usually affects the animal’s gait and often manifests when muscle control is lost. This results in poor coordination and balance. On the other hand, behavioral changes include aggression, anxiety, frenzy, or just an overall change in temperament.
In addition, there are non-specific signs that have been observed, such as loss in weight, decreased milk production, ear infections, teeth grinding, and lameness. (Source: CDC)
Can Mad Cow Disease Spread to Humans?
The agent can be transmitted to humans when food consumed is contaminated with it. The spread to humans is believed to result in variant Creutzfeldt-Jakob Disease or vCJD.
Since 1996, there have been 230 people infected with vCJD. Most of the cases have been identified in the UK and other European countries. While Mad Cow Disease is rare in the United States, there were 4 cases reported. The last 10 cases were identified in 1996. (Source: Johns Hopkins Medicine)
How Can Mad Cow Disease Be Prevented?
In order to control the spread of the disease, a ban on feeding meat-and-bone meals to cattle has been implemented. There is a significant reduction of cases in countries where the disease was prevalent. For countries that have not had any instances of the disease, strict import protocol and feeding regulations are set.
Slaughterhouses also play a vital role in controlling the spread of Mad Cow Disease. Organs like the brain, spinal cord, trigeminal ganglia, intestines, eyes, and tonsils from cattle that are identified as a risk must be disposed of according to protocol. As of 2009, an enhanced BSE-related feed ban was implemented in the United States. (Source: Johns Hopkins Medicine)