The case definition of Bovine Spongiform Encephalopathy (BSE) is a disease of adult cattle; affected animals display signs of a neurological disorder. The onset is usually insidious, and the effects may last from a couple of weeks to several months.
It is progressive and fatal; diagnosis can only be confirmed by histopathological changes in the brain or the demonstration of prion protein in the brain, according to the Department of Agriculture, Food and the Marine.
The neurological signs of BSE
These changes may be accompanied by other non-specific clinical signs although the presentation can vary considerably between individuals.
BSE non-specific signs
- Decreased milk yield;
- Weight loss;
- Decreased appetite.
A detailed history of the cow is crucial and should be observed undisturbed while trotting and while confined. The sensory disturbances often manifest when a cow is left undisturbed for a few minutes after a period of excitement such a trotting.
Diagnosis should always be considered in a differential diagnosis of ‘downer cows’, particularly if the hind legs are in an abnormal position.
If BSE cannot be ruled out, based on the history of a downer cow, she should be considered to be a suspect BSE case.
BSE is considered to be a single animal disease, rather than a herd problem.
The elimination of BSE from the national cattle herd is of vital importance. It is essential that veterinary surgeons and farmers have a good knowledge of the signs of the disease. Questionable adult cattle, where the disease cannot be ruled out, should be treated as BSE suspects.
All suspect cases should be reported to the District Veterinary Office.
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