Dunedin- A medical research company is applying to have rabbit calicivirus registered as a pesticide so it can be sold on the open market.

Dunedin-based Zenith Technology has applied to the Pesticides Board to have a calicivirus product, RCD-ZEN, registered. It hopes to have the product available for sale to farmers in the late summer or early autumn.

The virus has to be registered as a pesticide before it can be sold and used by contractors. A purified strain of the virus will be imported from Australia by the Ministry of Agriculture, which Zenith Technology will process and make available for use as a biological control.

Managing director Max Shepherd said the virus would be sold in 100ml bottles with instructions on how to use it as a biological control, based on experience from Australia. "By doing this we will provide farmers with a product of known potency and free from contaminating agents" Farmers have been using their own bush chemistry to brew up calicivirus from internal organs taken from infected rabbits. This has mostly been spread on carrots and oat baits as a biocide, similar to the way 1080 poison has been used.

Dr Shepard said the virus should not be used as a biocide as it could lose its virulence, spread unkown biological contaminants, and introduce immunity through sub-lethal doses or ingestion of inactive virus.

The biggest threat was rabbits developing immunity from the farmers brews, which would make use of purified virus ineffective. "There are a lot of dangers with the way it has been used," he said. Dr Shepherd said Zenith had been approached by a number of farmers and vets concerned RCD was losing its potency in the feild and looking for a solution.