Irish Authorities have identified a suspected case of Bovine spongiform encephalopathy (BSE), or "mad cow disease", on a dairy farm in County Louth, the first such case to be discovered in the republic since 2013.

The Irish Department of Agriculture said the five-year-old diseased cow was discovered as part of ongoing inspections of animals that die on farms.

"The animal was not presented for slaughter and did not enter the food chain. Confirmatory tests are being undertaken and results will be available in approximately one week," the department said in a statement.

If the case of BSE is confirmed it is likely that the World Organisation for Animal Health will downgrade Ireland's recently awarded "negligible risk status," severely denting confidence in Ireland's beef trade.

In the event, Ireland will revert to a "controlled risk status" from which it was only upgraded last week. The result will mean existing controls, as a result of Ireland's last case of BSE, will remain in place for a number of years.

The Irish Minister for Agriculture Simon Coveney said this appeared to be an isolated case, and there was absolutely no risk to people.

Coveney had earlier praised the lowering of Ireland's threat level as a landmark decision saying the new status "reflected the huge progress made over many years in eradicating this disease from the national herd".

Bovine spongiform encephalopathy (BSE)

Transmissible spongiform encephalopathies (TSEs) are a family of diseases of humans and animals characterized by spongy degeneration of the brain with severe and fatal neurological signs and symptoms.

In animals, scrapie is a common disease in sheep and goats. Mink and North American mule deer and elk can contract TSEs. Bovine spongiform encephalopathy (BSE) is also a TSE, affecting a number of species (cattle, human, cats, some types of animals in 300 settings).

BSE is a transmissible, neuro-degenerative fatal brain disease of cattle. The disease has a long incubation period of 4-5 years and it is fatal for cattle within weeks to months of its onset.

From October 1996 to March 2011, 175 cases of mad cow were reported in the United Kingdom, 25 in France, 5 in Spain, 4 in Ireland, 3 each in the Netherlands and the United States of America (USA), 2 each in Canada, Italy and Portugal, and one each in Japan, Saudi Arabia and Taiwan. The number of cases in the United Kingdom peaked in 2000 with 28 deaths. It has since declined to about 2 diagnosed cases and 2 deaths per year in 2008

Source: World Health Organisation