Expert lectures on myxomatosis

Press, 10 July 1985, Page 3

Expert lectures on myxomatosis

The rabbit population in Australia was reduced to less than 1 per cent of the original 750 million after the introduction of myxomatosis, an Australian researcher on the subject told a public meeting in Christchurch yesterday. “Areas which had been reduced to moss were producing pasture again. The whole country was transformed,” said Dr W. R. Sobey, an Australian scientist who has been involved in research on the disease for the last 30 years. The public meeting was organised by the Agricultural Pest Destruction Council to discuss the proposed introduction of the disease. The meeting was attended by about 100 people, including farmers, anti-vivisec-tionists, members of the Society for the Prevention of Cruelty to Animals, and other animal protection groups. Dr Sobey told the meeting that the virus had remained virulent over the last 30 years, and that immunity which was generated by it reached a plateau in the first five years. He said the first attempt at the introduction of myxomatosis in New Zealand in 1951, lasted only two years because of the lack of a carrier. In Australia, mosquitoes were relied on to carry the virus, as well as the European rabbit flea, but that flea had not yet been introduced in New Zealand. The climate in the areas worst affected by rabbits — the inland high country in the South Island — was too cold for mosquitoes. New Zealand had an advantage over Australia in the introduction of the virus, because of the extensive research which had been carried out on it since the introduction of mxyomotosis in Australia after World War 11. The introduction of myxomatosis in New Zealand would see an improvment in the environment he said. Dr Sobey said that rabbits were the worst agricultural pest in existence, and that there was a whole generation of people who were not aware of how damaging they were. Dr Sobey said that one worry expressed by opposition to myxomatosis was

that it could spread to commericially farmed rabbits. Rabbits could be immunised against the virus, he said. “I don’t know what cost it would be but it isn’t that much,” he said. The disease would not affect the domestic rabbit industry if the carriers of the virus were kept out. This was relatively easy to do. “In my experience it is possible to breed rabbits in one room and test for mxymatosis in the next,” said Dr Sobey. “Provided one is responsible and careful there is not much to worry about.” Those selling rabbits for rabbit meat could argue that it would make people reluctant to buy it, but they could also argue that domestic rabbits were the only ones totally free of myxomatosis. People could not pick up any disease from eating an infected rabbit, nor could domestic animals or any other animal, he said.

“Myxomatosis is a very specialised virus.” It was so specialised that it could only breed in rabbits. The life cycle of the flea carrying the virus was so close to that of rabbits that it was impossible for it to breed on other animals although cats and hares could carry it. In the 30 years that the virus had been in Australia not one other species had been affected. In answer to a question by an anti-vivisectionist, Dr Sobey said that the rabbit would begin to show the symptoms of the disease five to seven days after being infected. The first symptoms were a swelling of the mouth, eyes, ears and anus. The rabbits generally died as the virus took over more body tissues, after about 11 days. The chairman of the Agricultural Pest Destruction Council, Mr Ged Foley, told the meeting that the main infestations of rabbits were in the South Island high country. Poisoning them was not working, because of the reluctance of rabbits to accept the bait. Mr Foley assured the meeting that if myxomatosis were introduced and killed off 90 per cent of the rabbit population, as was expected, the pest destruction boards would do all that was in their power to try to eradicate the other 10 per cent of rabbits.