Eight years' experience with a register of pig herds monitored for Aujeszky's disease.

The Pig Health Control Association launched a control scheme for Aujeszky's disease in Britain in January 1978. Participating herds must not show clinical signs suggestive of Aujeszky's disease and must be serum-sampled every six months for the absence of antibodies. Importations are allowed only from listed herds, or through hysterectomy or hysterotomy, embryo transfer, or artificial insemination (the donor animals in each case having been serologically screened beforehand). During the subsequent eight years, 103 herds have qualified, and at the end of 1985, 49 herds (average size 249 sows) were listed. Despite a high degree of inter-herd stock movements, no clinical or serological evidence of Aujeszky's disease has occurred, and the disease has not arisen in any herd established from the listed herds. During the same period, Aujeszky's disease was spreading in Britain and an eradication programme began in March 1983. By the end of 1985, 502 herds not on the Pig Health Control Association's scheme comprising 421,825 pigs had been slaughtered, together with 259 serologically positive animals in 69 other herds. The Pig Health Control Association's register has provided a safe source of stock.