Pig industry under threat from disease

Source: http://www.thetimes.co.uk/article/0,,2-2001331316,00.html

by Valerie Elliott, Countryside Editor
September 24, 2001s

New diseases that are killing thousands of pigs and for which there are no known cures could prove devastating to the industry, according to farmers. Stewart Houston, chairman of the National Pig Association, said last night: "The effect of these new diseases is likely to be tragic and really could sound the death knell for the pig industry. So many people are now really struggling and they will have to decide whether to stay or quit the industry."

The disease takes 2 forms -- pigs suffer a sudden death and are found in their pens, or they become listless, gaunt, and physically waste away. Some also have a purple rash on their skin.

Farmers are desperate to find ways to protect their stock from the disease, for which there are no cures or treatments. Meat industry experts believe that about 300 000 pigs could die from the disease.

Vets insist, however, that there is no threat to human health.

The disease, which was first recognised in England in the South West 2- &-a-half years ago, is spreading quickly throughout the country. Last year the disease was confined to outdoor pig units in East Anglia, but has now been found at indoor units and spread as far north as Yorkshire and Humberside. Farmers and vets believe that the surge could be related to the outbreak of classical swine fever (CSF) in East Anglia last year.

Pig producers in Scotland, where there has been one suspected case, are so concerned that they have banned pigs from the south crossing the border, although foot-and-mouth movement controls remain in place for the moment anyway.

The 2 linked diseases are known as post-weaning multi-systemic wasting syndrome (PMWS) and porcine dermatitis nephropathy syndrome (PDNS).

PMWS appears to affect pigs aged 6-14 weeks. Pigs are normally reared for 20 to 23 weeks before going to slaughter.

PDNS affects pigs of 12 to 14 weeks. Once the virus is present in a herd it can take 2 years to eradicate.

About 60 per cent of the country's producers have experienced high rates of pig mortality. The cost in lost pig meat sales to the country is estimated at GBP 21 million [in 2oo1]. But the cost to the industry is far higher, as farmers must still pay for feed, vets, and carcass disposal, even though they receive no income from the dead animals. Pigs from farms with the diseases are unlikely to be sold as breeding stock.

Bob Stevenson, a veterinarian and pig adviser to the British Veterinary Association, said last night that there was near panic among farmers who were free of the diseases. "They worry about buying new stock because breeding companies cannot give assurances about the healthy state of their pigs. In disease terms it really is a big fear, especially as the disease is so new to the UK." However, he said that although some farms had experienced up to 30% mortality, some pigs appeared to recover with nursing and good stockmanship.

Government vets are planning a survey of private vets to establish the number of cases in the country this year and to see if there are similar patterns of pig behaviour.

Mr Houston will meet Elliot Morley, the Animal Health and Welfare Minister, next month to press the Government to fund new research into the diseases. Ministers and government vets know of the threat to the pig industry, but have been concentrating on wiping out CSF and foot-and-mouth. Mr Houston said that the real concern for farmers was that they did not know how best to protect their animals, and that there was no treatment on offer.

Vets believe that the diseases are linked to circovirus, which is found in pigs, but they do not know what triggers the virus to cause sudden death from the wasting condition. Some experts think the disease is spread by birds, rats, and mice. Farmers have been told to maintain strict pest control on their farms. Another theory is that the disease may be passed through semen. Stress is also thought to be a factor. Farmers are now reducing the number of pigs held in pens, cleaning out pens, replacing straw and water more frequently and ensuring that pig feed is free from mould.