The cancer-causing virus Ovine Pulmonary Adenocarcinoma (OPA), an iceberg disease, is being seen more often on sheep farms, Shane McGettrick told farmers.
Shane was speaking at the Teagasc National Hill Sheep Conference last Thursday (February 24), at the Clayton Hotel in Co. Sligo.
McGettrick is a Laboratory manager with the Department of Agriculture, Food and the Marine’s Regional Veterinary Laboratory in Co. Sligo.
Speaking about iceberg diseases, Shane said: “An iceberg disease is when what you see is only the tip of it. There’s lot more going on than what the eye sees.
“One such iceberg disease we are seeing more of is OPA, which is a virus that gets into the lung and causes a tumour in the lung, which causes a lot of fluid to build up.
“That tumour actually causes the animal to suffocate in the fluid it’s producing. It’s one of the very rare things we see in nature in that it’s a virus causing cancer.
“And it’s becoming more common on sheep farms. Other iceberg diseases we are seeing are caseous lymphadenitis, which is a bacterial disease that enters through the lymph nodes.”
Shane then gave examples of other iceberg diseases.
“Border disease, which is the equivalent of Bovine Viral Diarrhea (BVD) in sheep and as the BVD eradication programme comes to an end in cattle, there is going to be an increased focus on border disease in sheep.
“Johne’s disease, which you are probably more familiar with in cattle, but it can also affect sheep, causing ill thrift.
“The last one I’m going to mention is Maedi Visna,” Shane said.
“We didn’t think we had this disease up until a few years ago. We’ve, however, identified a few cases of it recently. It’s something that sheep farmers are going to be hearing more and more about in the future, so I just wanted to mention it.”