Bovine spongiform encepalopathy

Bovine spongiform encepalopathy (BSE), popularly known as mad cow disease, is an incurable, progressive, and fatal neurological disease. It appears to be transmitted by abnormal prion proteins in the brain.

Affected animals develop excitability and salivation followed by ataxia. This disorder has been associated with consumption of scrapie infected ruminant derived protein.

Prevention

It has largely been controlled in the industrialized world, through vigorous quarantine and herd euthanasia. A major step was a prohibition of the use of central nervous system products in animal feed; while cattle are vegetarians, it was a surprise to many that a number of commercial cattle feeds did contain meat by-products as a source of protein.

As an example of the stringency and effect of control, a single case was reported, in the Netherlands, in September 2008, the first in over two years. ProMed added to the Reuters report, "the number of slaughtered cows, older than 30 months, which were compulsorily tested in Dutch slaughterhouses for BSE, was about 405 000 -- all with negative results. Suspected cases are withheld until the receipt of final results from the Central Veterinary Institute (CVI) in Lelystad. According to CVI, sporadic cases of BSE may still occur in the Netherlands during the coming years." An interactive epidemiological map is available.[1].

Human disease

This condition may be transmitted to humans, where it is referred to as variant or new variant Creuzfeldt-Jakob syndrome.