Veterinary experience at Orchard Vet Centre, Armagh has highlighted how BVD can affect animals of all ages, and the practice welcomes the compulsory BVD tissue tagging which is being introduced from 1st March.
Veterinary surgeon, John Henderson highlights one of the cases he has been involved with “The farmer had lost 3 finishing cattle from the same house to pneumonia. Regular treatment had little or no effect and the cattle had died. The subsequent post mortem showed severe sudden lung damage. When another animal was lost we decided to investigate why big strong cattle from the same group were dying so easily. We blood sampled the rest of the cattle in that pen, about 12 or so, and a U grade Belgian Blue bullock proved positive for BVD. It was a PI (Persistently Infected) that was weakening the other cattle in its pen by showering them with BVD virus from its breath, urine and dung. This animal was quickly slaughtered and the problems stopped. This is unusual as most PI animals will die before they reach that age but it shows how dangerous a PI can become if it is retained in the herd.”
John added “Every week in the practice we take blood tests from cattle we suspect are PI’s. Positive results turn up on a regular basis. Sometimes these are weakly, stunted calves way behind their comrades but sometimes they are good suckled calves, often bought from a mart, who suddenly take sick with scour and other diseases which prove impossible to clear up. These PI calves had been fine until the stress of the movement and change of environment bring on the BVD related diseases which are always fatal.”
John has also noted a few farm visits where he was doing pregnancy scanning and the results were very poor for a farm where management was excellent and previous scans had always shown results above average. The cause of the poor fertility was eventually established – it was due to one or two positive PI animals in the herd.
He added “This virus weakens the immune system and allows common infections to get a grip on the cattle. If the virus gets into pregnant cows it can kill the developing embryo causing more cows to run to the bull. Any foetuses that survive run the risk of being born as PI’S, continuing the cycle of BVD infection into the next year. BVD can thus become an ongoing cause of lost income.”
In order to inform farmers about the new scheme Orchard Vet Centre is organising a meeting in conjunction with Countryside Services.. Ian McNiece from Countryside Services explained “There will be a full explanation on how to use the tissue tagging system, and veterinary advice on all aspects of the sampling procedures particularly on dealing with positive results. Any farmer is welcome to attend the meeting.”
The meeting will take place in the City Hotel, Armagh next Tuesday (9th February) at 7.30 PM. For further details Countryside Services can be contacted on 028 8778 9770 while Orchard Vet Centre can be contacted on 028 3751 0088.