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Approximately 3.5% of sheep presented for post-mortem at AFBI regional laboratories have died from Ovine Pulmonary Adrenocarcinoma (OPA), or Jaagsiekte. That compares to a figure of 2.2% from 2012.
At an OPA awareness event held at CAFRE’s hill farm at Glenwherry last week, AFBI vet Jason Barley told farmers present that the condition is now common in most NI sheep flocks.
He outlined how OPA is a highly infectious and fatal lung condition that is easily transmitted between animals, both old and young.
It has been confirmed in lowland and hill flocks, with all sheep breeds being affected by the disease.
Tumors
OPA is caused by the Jaagsiekte virus which leads to tumours in the lungs. Symptoms include loss of body condition, as well as increased problems with pasturella and viral pneumonia in animals, especially housed sheep.
Diagnosing the condition in live animals is difficult as there is no blood test to confirm the presence of the virus.
As symptoms are slow to materialise in younger sheep, the early signs of OPA are often missed or accredited to a different disease.
Scanning
However, the use of purpose-designed ultrasound scanners is helping to control the incidence of OPA in flocks.
Scanning the sheep’s lungs identifies tumours early, and these animals can be immediately separated from the flock for culling.
Sheep vet Patrick Grant demonstrated how the scanner works, with the optimum time to scan being the summer months, between weaning and the onset of breeding.
Costs of scanning are around £2/ewe, with Grant confirming that, to date, the flocks scanned have around 5% to 6% of sheep affected by OPA.
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