As investigations continue into the age of a BSE-infected Kerry cow which may be younger than six years, the number of cases of the disease so far this year has reached 200.
In the same period last year, the authorities had identified only 67 animals suffering from the disease on Irish farms.
The Department has stepped up its tests for the disease and the numbers have soared as a result of testing diseased and casualty animals being delivered to knackeries for destruction into bonemeal.
The Kerry investigation is concentrating on an animal which may have been born after the controls on feeding meat and bonemeal became fully operational.
One other young animal has already been identified so far this year.
The cases this week were in herds in Cavan, Cork, Tipperary, Monaghan and Clare and all the animals were six years or older.
The six-year-old case came from a Cavan dairy herd and the seven-year-old victims were found in beef and dairy herds in Cavan, Cork and Clare.
The eight-year-olds came from a dairy farm in Monaghan and the two nine-year-olds from beef farms in Tipperary and Cavan. An 11-year-old cow came from a Cork farm.
Three of the cases were detected by farmers on their own lands and the remaining six cases were found by the Department's active surveillance measures at knackeries.
Since the disease was identified here in 1989, 1,042 cases have been uncovered.
Up until 1996, the annual total was less than 20, but has been climbing since then.
All animals over 30 months destined for human consumption are tested for BSE and the specified risk material which could harbour the disease is removed from animals and destroyed.