Following is a letter I received from the RCD(RHDV) Program (in reply) 7 September 1997


Rabbit Calicivirus Disease Program
(A biological control initiative against the European wild rabbit)


Mrs Marguerite Wegner
Rabbit Information Service
PO Box 30
RIVERTON WA 6148


Dear Ms Wegner

In answer to your queries regarding RCD baits the following information has been supplied by the Chair of the RCD Program Science Sub-Committee.

Q.Are the RCD/RHD baits being tested in open field testing?

A.The baits are being tested in cage trials and in open pens.

Q.What type of tests are being undertaken to test these baits?

A.The tests are in rabbits. Wild rabbits are trapped and blood tested for antibodies to RCD virus. They are then fed baits containing various concentrations of virus. The mortality rate is recorded. Livers from dead animals are tested for the presence of the virus and recovered animals retested for antibody.

Q.What precautions are being undertaken to make the baits species specific to the intended target animal (i.e. rabbits)?

A.For the pen trials the bait is put out in the late evening to reduce the opportunity for the baits to be taken by birds, sulphur crested cockatoos in particular. This is to make sure that there is sufficient bait for the rabbits.

Q.How can you regulate the dosage of RHD ingested by any animal that eats the RHD baits when such ingestion of baits occurs in the field?

A.Obviously the dosage is determined by the individual animal. For rabbits, an average nightly consumption can be calculated on a population basis and an amount distributed that would be likely to be consumed in one night.

Q.What type of broadcasting of these baits do you envisage will be sought by the proponents?

A.Probably small amounts placed near warrens. Cost is likely to be the major factor.

Q.When do you believe that these baits will be ready for approval by NRA?

A.The latest estimate is the end of October 1997.

Q.Are the baits being developed a wheat based bait?

A.No.

Q.Is it an aim of developing the RCD/RHD baits, that the RCD baits will eventually be available for purchase by farmers over the counter (once the baits are approved by the NRA)?

A.That has not been decided but most likely it will be restricted to State pest control officers to ensure proper storage conditions and distribution at times when the bait is most likely to be effective. This is a decision of the NRA. The current injectable form is not available over the counter.


Yours sincerely


M Hillier
Executive Officer
RCD Management Group

7 September 1997