All bought-in sheep should be quarantined on farm for at least a month, before being allowed mix with existing flock members,” according to Professor Michael Doherty, from UCD’s School of Veterinary Medicine.

“This will give the purchaser an opportunity to assess what diseases, if any, the new arrivals are carrying,” he said.

Professor Doherty was speaking at the Teagsc Annual Sheep Conference in Trim recently.

“Farmers may well have enough disease-related issues  to cope within their existing flocks: so the last thing they need is to import additional problems.”

Doherty went on to point out that quarantine means strict isolation of the new arrivals from all other sheep already on-farm.

“Maintaining the highest levels of biosecurity is an absolute priority for the sheep sector,” he said.

“There is a host of diseases now impacting on the sheep sector, for which neither a cure or vaccination programme is available.

“What’s more, problems such as foot rot or scab may only be at the very early stages of development at time of purchase and, as a result, will not visible to the naked eye.

“So, again, it makes sense to quarantine bought-in animals for a number of weeks. If health problems are identified then the farmer can take the necessary steps in terms of dealing with these issues.”

Doherty referenced diseases such as Jaagsiekte, a chronic lung disease and CLA, a bacterial infection of the lymph nodes, as becoming more prevalent within the Irish sheep flock.

“Part of the problem is that we have yet to carry out comprehensive research to identify the spread of these diseases within the national flock. Only then can we come up with some form of eradication programme.

“Both of these problems were introduced to Ireland by way of sheep importations. The same can be said for CODD and Scrapie. There is also strong evidence to show that anthelmintic resistance has been introduced to individual flocks courtesy of bought-in sheep.

“So I cannot stress strongly enough the need for flockowners to isolate bought-in sheep directly after purchase.

“I would also advise flockowners not to allow other sheep producers to use their handling and dipping facilities. Again, this is just asking for trouble from a biosecurity point of view.”