ATYPICAL bovine spongiform encephalopathy (BSE) has been detected in a 14 year old Limousin cow in Ireland, the World Organisation for Animal Health (OIE) confirmed overnight.
Ireland’s Department of Agriculture, Food and the Marine (DAFM) was advised of a positive result to a rapid screening test carried out by an accredited private laboratory on May 12.
The suspect animal from Fethard, Tipperary, was sampled by DAFM staff as part of the ongoing official sampling of all fallen animals of 48 months and older.
The sample material and brain were subsequently forwarded to the National Reference Laboratory (NRL) where samples from different brain areas were found to have an identical molecular pattern indicating atypical H type BSE.
Final confirmatory test results were received from the NRL on 22nd of May 2020 confirming the case to be atypical H type BSE.
The cow involved in this case was a 14-year-old Limousin cow born on the 8th of March 2006.
The cow was part of a suckler herd of 73 cattle and remained in that herd until her death on Saturday May 9th.
The cow had had a history of neurological signs which were first noted at the end of March 2020, where the cow became ataxic and recumbent, but got back on her feet with some assistance.
A further such episode occurred in April 2020, and again on Saturday May 9th, the OIE report stated.
The farmer intended to call his private veterinary surgeon (PVP) to look at the animal at that time, but she had died before he had the opportunity to call his PVP. The cow was well conditioned, up to her death.
The OIE said all susceptible animals were culled and tested negative for BSE, and the case has now been resolved.
Following the first diagnosis of BSE in Ireland in 1989 a number of risk management measures were introduced, including legislation making it compulsory for veterinary surgeons, farmers and all other persons in charge of bovine animals to notify the Department of Agriculture, Food and the Marine (DAFM) of any animal displaying clinical signs consistent with BSE.
In 1990 a ban on the feeding of meat-and-bone meal (MBM) to ruminant animals was introduced.
Since the mid 1990s a series of cumulative risk management measures have been in place involving disease surveillance and control measures (removing infected animals); exclusion of specified risk material (SRM) from human food and animal feed chains (removing from all animals, and destroying, the tissues shown to be capable of transmitting the BSE agent); and preventing access to MBM by all ruminant animals.
The DAFM said clear evidence that these measures have been effective is provided by a substantial decline in the prevalence of disease observed over the past decade.
The incidence of BSE is expected to continue to decline, as animals born before the introduction of the additional controls in 1996 and 1997 leave the cattle population.
Since 2006, the majority of BSE cases have been diagnosed in animals that were over 12 years of age at the time of diagnosis.
In May 2008, the OIE officially recognised Ireland as a country with a controlled risk for BSE, a classification which was re-affirmed in June 2015. The classification recognises that Ireland’s regulatory controls are effective, and Irish beef can be safely traded internationally due to the interlocking safeguards described above.
Ireland last reported an atypical case of BSE in January 2017 when an 18-year-old cow returned a positive result after being tested at a Knackery as part of Ireland’s ongoing sampling of animals over 48 months old that have died on farm.
The 2017 case of atypical BSE did not have any impact on Ireland’s OIE ‘controlled risk’ BSE status, or trade access, the OIE indicated in a report. Ireland is one of the largest beef exporters within the EU group of countries.
There are two types of BSE currently recognised – classical and a-typical. Classical BSE is associated with the (now banned) feeding of meat-and-bone meal, and evidence shows that BSE is acquired in the first year of life, while atypical BSE is thought to occur spontaneously in older animals at a much lower incidence rate.