VET’S CORNER BSE case is proof our testing works

S I left school and enrolled in the Faculty of Veterinary Medicine at Glasgow University back in the early 1990s, BSE was wreaking havoc in the cattle farming industry. This week, an isolated case of BSE was diagnosed in a cow from a farm in Aberdeenshire.

BSE or Bovine Spongiform Encephalopathy was a disease of the brain and spinal cord in cattle that resulted in severe neurological signs. Also known as “mad cow disease”, BSE would eventually be fatal.

Scientists believe that BSE is most often spread through the practice of feeding cattle various meats (rendered material) from slaughtered animals such as sheep, goats, and other cattle.

During this process, an abnormal protein that is linked to BSE can spread from a slaughtered diseased animal to a healthy one. This abnormal protein, called a prion, can withstand high temperatures and does not get destroyed during the rendering procedure.

The cells most often infected are the brain cells. The resulting solidification of the proteins causes the infected brain tissues to look like a sponge with several tiny holes, hence the name “spongiform encephalopathy.”

Cows with BSE may show nervousness or aggressive behaviour, difficulty with co-ordination, trouble standing up, decreased milk production, and weight loss. The disease is fatal, with death usually occurring two weeks to six months after symptoms start.

The only way to confirm the presence of BSE is by checking the brain tissue of an animal after it dies and this is exactly how the recent case in Scotland was detected. Despite the BSE incidence being at its height in the early 1990s, thousands of samples continue to be monitored in abattoirs to ensure that cases are picked up. It is a mark of just how rare BSE now is that this one cow has hit the headlines this week.

Back in the 90s, the animal proteins that were thought to be a potential source of BSE were banned from cattle feed and gradually, the incidence to BSE declined however we do not clearly understand how this recent case has occurred.

It is very important to understand that, since the 1990s, rigorous procedures were put in place to ensure that no brain or spinal cord tissue can make it into the human food chain so that there can be no risk to public health.

I find it very reassuring that this recent case was detected at such an early stage and that rigorous testing is now under way with the rest of the herd to ensure that this is a solitary case