North Canterbury farmers are spreading rabbit calicivirus by the same do-it-yourself approach as their Mackenzie Basin counterparts as rabbits in the region are starting to breed.

The virus has been spread throughout some of the more rabbit-prone parts of the region during the past two weeks, even though it is not yet legal to possess or spread it. John Acton-Adams, who farms in the Amberley foothills 50 kilometres north of Christchurch, said spreading the virus in North Canterbury had only taken place in the past fortnight, after Cabinet decision to try to legalise its spread. The Government has not yet passed regulations to make the virus legal.

The rabbit breeding season had started, and farmers were in a rush to get the virus spread as soon as the Government cleared up the legal position, Mr Acton-Adams said. Newborn rabbits were immune to RCD for the first eight weeks and farmers wanted to achieve a kill while they were still dependant on adults and unable to survive by themselves. Farmers were sharing inoculant or having rabbits inoculated, waiting for them to die, then using the organs to make more "rabbit smoothie" inoculant, which was mixed with pulp or jam or sprayed on oats or carrots.

Farmers were first given clues on how to prepare the RCD inoculant by Ministry of Agriculture's semi-arid lands group at Lincoln, in 1991.