Isolation of BVD virus Positive cattle is critical 09/11/2020

Isolation of BVD virus Positive cattle is critical   

Strict isolation of BVD virus Positive cattle is essential if further transmission of the BVD virus is to be stopped and to protect herds that are clear of the disease: at the start of November this advice applied to 244 BVD virus Positive cattle alive in NI in 173 herds.

The rapid removal of virus positive animals is crucial but effective ‘distancing’ of known BVD Positive cattle as soon as they are identified is necessary in order to reduce the risk of the BVD virus spreading to healthy animals, particularly in-calf stock.  Isolation can prevent this contagious organism from circulating in the herd and therefore shorten the length of time for which the BVD virus is present on the farm.  Transmission of the virus to pregnant stock will mean that the virus will be carried over to the next breeding season, with likely adverse effects on fertility and calf health.

Latest data from the BVD Programme indicates that the number of herds affected by BVD continues to fall: approximately 1,700 cattle in 900 herds were disclosed as being BVD Positive in the last 12 months, a significant decrease from 2019 when approximately 2,000 BVD Positive cattle were disclosed in just over 1,000 herds.  However, in order to stamp out BVD, it is important that animals suspected of having BVD are segregated from the rest of the herd, until they either receive a BVD Negative result on a retest or are culled.

Isolation of an infectious or potentially infectious bovine is a requirement under the BVD Control Order (NI) 2016.  This applies to cattle with BVD Positive or inconclusive results as well as the Dams and Offspring of Persistently Infected (PI) animals.  The affected cattle must be isolated within housing (that is, not outdoors) to prevent direct or indirect contact with other susceptible animals. 

Isolation premises should be a discrete unit that is secure and suitable for housing cattle.  It should have a separate airspace and separate drainage from other farm buildings.  There must not be any physical nose-to-nose contact possible with other cattle or sheep and sharing of equipment (including handling facilities) or utensils with other groups of stock should be avoided.  Anyone working with these high-risk animals should wear footwear and clothing that is dedicated for the premises, or that can be cleansed and disinfected before leaving. 

The welfare of an animal in isolation is important and it is recognised that on occasion an isolated animal may need to be kept with another bovine animal.  (The additional animal may be the dam of a beef calf, or an animal that has had a BVD virus Negative test result and not be intended for breeding).

Once the isolation facility is emptied, cleansing and disinfection using DAERA approved disinfectants at the appropriate concentration should be completed, so that subsequent batches of stock do not pick up the virus from contaminated material.