The World Organisation for Animal Health (OIE) has reported the full background to the BSE case in Co. Louth.
Based on information received on from the Irish Chief Veterinary Officer Dr Martin Blake, Chief Veterinary Officer the OIE says the Department of Agriculture in Ireland was first of a positive result to a rapid screening test on Tuesday, June 9.
It was Thursday, June 11, when the Department made the result public.
The OIE says that the case first started when the animal, a Rotbunt female, born on 14 January 2010, went down. The animal was born, reared and spent its entire life on the same farm.
The farmer reported that the animal had fallen on 24 February 2015 but had recovered. The animal fell once again on June 6, 2015.
The animal did not recover and the farmer took the decision to have the animal euthanized. Approximately six weeks prior to death the farmer had noted that the animal had lost body condition, milk yield reduced, and the animal displayed some neurological signs such as nervousness and hyperexcitability.
The suspect animal was sampled by DAFM staff at a knackery as part of the on-going official sampling of all fallen (died on farm) animals of 48 months and older.
The sample material and the brain were subsequently forwarded to the National Reference Laboratory (NRL) where samples from different brain areas were subject to confirmatory testing using an OIE-approved confirmatory Western blot method (Biorad TeSeE).
In addition, the samples were subject to a two-blot protocol for the classification of BSE isolates. All the samples had an identical molecular pattern indicating classical BSE. In accordance with NRL protocols, samples from the animal were then sent for histopathology and immunohistochemistry on the medulla of the brain. These are further OIE confirmatory testing methods for BSE.
In addition, samples were also forwarded to the European Union Reference Laboratory in Weybridge, United Kingdom. Final confirmatory test results were received from both laboratories on June 25, 2015, confirming the case to be classical BSE.
Both the dam and grand-dam of the infected animal were tested for BSE when they were slaughtered as healthy animals in 2006 and in 2013. Both animals tested negative for BSE.
The identification of the ‘cohort’ group took into account animals born in the herd in the same year (2010) as the case, in the previous year (2009) and the following year (2011). The objective was to identify those animals which might have consumed the same feed as the case animal. Sixty three animals were still alive.
With regard to the progeny of the cow, all four animals were identified. All progeny and cohort animals that had been identified, traced and restricted were removed and slaughtered on June 22, 2015. Samples from all these animals were subjected to testing for BSE. Results from these tests were delivered on June 23, 2015 – all 67 animals tested negative.