ALL COWS born in Ireland from tomorrow will be required to undergo mandatory testing for a bovine form of viral diarrhoea which can prove fatal if spread to vulnerable calves.

Agriculture minister Simon Coveney has issued an order which will require all newborn cattle born from January 2013 onward to be tested for the Bovine Viral Diarrhoea Virus.

Anyone who owns or controls a newborn bovine will be required to take a sample from the animal and submit it to a designated laboratory to be tested for the virus.

Bovine viral diarrhoea can often be difficult to immediately diagnose because it is spread by a small population of cows which become ‘persistently infected’ with the virus, but which themselves become immune to it within just a few weeks.

This means a mother which can appear perfectly healthy is actually passing on the virus to its own offspring, some of which could appear completely healthy but which may in turn act as a carrier for the disease and facilitating its spread to other healthy calves.

In many cases, however, calves which become persistently infected are stunted and never reach their full growth or fertile potential.

Other symptoms of the virus include spontaneous abortions among pregnant cows, infertility, and a mucosal disease which can see cows develop blisters and ulcers around the mouth and snout, and which usually proves fatal.

The virus poses no threat to human health, however.