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Mad Cow Disease

Explainer: What is BSE - and should we be concerned about this case?

Where does BSE come from? Is there any risk to humans? Why is this case generating such attention? And what’s the possible damage to business?

shutterstock_205975501 Shutterstock / the goatman Shutterstock / the goatman / the goatman

A CASE OF BSE has been confirmed in a five-year-old dairy cow on an Irish farm.

The story dominated newspaper headlines and broadcast news bulletins when it first broke on 11 June.

Confirmed this evening, it is the first BSE case found in Ireland since 2013.

So what is BSE – or Mad Cow Disease? And why is this case generating such attention?

Your questions, answered…

BSE… What is it?

Bovine Spongiform Encephalopathy (BSE) is a disease that affects adult cattle.

It attacks the brain and central nervous system of the animal – and eventually causes death.

Commonly known as Mad-Cow Disease, it has a long incubation period, meaning that it usually takes four to six years for infected cattle to show signs of the disease.

Symptoms include disorientation, clumsiness – and, occasionally, aggressive behaviour towards other animals and humans.

What happened in the 1990s?

The BSE crisis, which reached its peak in Ireland the mid-1990s, was hugely damaging to the industry.

The Irish Farmers Association estimated back in 1996, when the crisis was at its worst, that it had knocked over £1 billion (in punts) off the value of the cattle herd.

Tens of thousands of cattle were culled in response.

File Photo: A dairy cow has died on a farm in County Louth of suspected BSE (mad cow disease). A further test is needed to confirm the cow was infected. It is expected the second result will be known in a week. The last case of the disease in Ireland was /Photocall Ireland /Photocall Ireland

Where does BSE come from? 

BSE was first confirmed in cattle in the UK in 1986.

The first case in Ireland was confirmed in 1989 – when there were 15 cases confirmed.

The brain disease ‘Scrapie’ was first recorded in sheep way back in 1732 – and was first discovered in a cow in France 1883.

It’s believed it reappeared in cattle between the 1970s and 80s when changes in the ‘rendering’ process meant it ‘jumped species’ (see below).

How does it spread? 

Most experts agree that BSE was most likely spread by cattle eating feed that contained contaminated Meat and Bone Meal (MBM) – produced in a process called rendering (where otherwise unused animal products are taken from the carcass and are cooked for a long time).

MBM was incorporated into cattle feed until it was banned in the 1990s.

Experiments have shown that cattle can contract BSE if they are fed infected brain tissue. This seems to support the idea that BSE was transmitted to cattle through their animal feed.

shutterstock_265088387 Human prion protein Shutterstock / Science Photo Library Shutterstock / Science Photo Library / Science Photo Library

What controls have been put in place?

The practice of feeding Meat and Bone Meal to cattle has been banned in Ireland since 1990.

Controls on MBM were strengthened in 1996 -1997.

Due to the BSE crises in other member states, a ban was introduced throughout the EU on feeding MBM to all farm animals in 2001.

(Note: More detail on controls available from the FSAI and Department of Agriculture)

What is the danger to people? 

BSE only develops in cattle – but it belongs to a family of prion diseases, several of which can affect humans.

The most commonly known disease in this group among humans is Creutzfeldt-Jakob Disease (CJD) – a rare and fatal form of dementia that normally occurs in people aged between 40 and 80.

CJD is not a new disease among humans – but in 1996, scientists discovered a new strain of CJD that occurs predominantly in younger people.

Evidence has shown that the protein that accumulates in the brains of patients with this new form of CJD is similar to the protein found in cattle infected with BSE, rather than that found in classical CJD.

Because of this discovery, the new illness in humans is known as variant CJD or vCJD.

Human BSE memorial Day Thomas Goodwin from Glasgow, father of Grant (in picture) who died aged 30 from vCJD, marks Human BSE memorial Day in London in 2010. PA WIRE PA WIRE

What’s the link?

The occurrence of the new form of CJD in the UK , where there was a high incidence of BSE, suggested that there might be a direct link between BSE and vCJD.

Some people who had developed vCJD were known to have eaten potentially BSE-infected meat products.

Researchers concluded that the most likely origin of the new disease was human exposure to the BSE agent.

Like BSE in cattle, vCJD is always fatal in people.

So is there any risk here? 

The Food Safety Authority of Ireland were quick to point out that, as the animal didn’t enter the food chain, there is no risk to humans.

Agriculture Minister Simon Coveney and other senior government officials have also been stressing that beef is perfectly safe. “Absolutely no risk,” Coveney said in a radio interview.

File Photo: A dairy cow has died on a farm in Coun Eamonn Farrell / Photocall Ireland Eamonn Farrell / Photocall Ireland / Photocall Ireland

So why is this case generating such attention?

Beef is huge business in Ireland – and the suspected BSE case doesn’t do us any favours on the publicity front.

The OIE (World Organisation for Animal Health) last week put Ireland on ‘clear’ status regarding our beef after 11 years of being seen as a controlled risk.

The Department of Agriculture conceded that the new case will likely see Ireland’s international beef status downgraded.

In 2014, Ireland exported an estimated 524,000 tonnes of beef – worth approximately €2.27 billion, along with live exports worth €172 million.

So, obviously, we could do without international news stories like this…


And what are farmers saying? 

The IFA is satisfied that export and domestic markets reacted in a ‘calm and balanced manner’.

President Eddie Downey said consumers can be reassured about the “robustness of the food safety controls in place in Ireland”.

Meat Industry Ireland also said that international markets remained unaffected by the incident.

“Following the initial announcement, member companies have maintained close contact with customers in Ireland and abroad and have reported business as usual in international markets,” the group said in a statement.

s Simon Coveney Photocall Ireland Photocall Ireland

[Sources: FSAIDepartment of Agriculture, Bord Bia, IFA,, Guardian

More: Suspected BSE case is ’80% likely’ to test positive for the disease

Read: ‘How does a five-year-old cow have BSE?’ – Simon Coveney

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