The High Court has upheld the legality of using ventilation shutdown as a last resort for culling commercial flocks in the event of an outbreak of avian flu, according to a BBC report.

Lord Justice Auld rejected a claim from the RSPCA who brought the case to the court that ventilation shutdown was “disproportionate”.

Ventilation shutdown was allowed under an amendment in April 2006 to the Welfare of Animals regulations 1995 for use in “exceptional circumstances”.

After the ruling, the RSPCA stressed that it still opposed the method which it claimed would cause “substantial suffering and distress”. The charity argued that the rules were incompatable with a 1993 EU directive on the welfare of animals at the time of slaughter or killing.

The judge added: “The practical difficulties of providing an all-purpose method – or variety of methods – of ventilation shutdown, so as to provide a guarantee of no distress, pain or suffering when meeting an emergency in all circumstances and countrywide are so obvious as to demonstrate the unreality and imbalance of the RSPCA’s case.”

Reacting to the decision, RSPCA head of external affairs David Bowles said: “The RSPCA is disappointed with the outcome of the review, and continues to strongly oppose the use of ventilation shutdown, on the basis that it would cause substantial suffering and distress to birds.”

DEFRA said the technique would be used only if no other method was possible.