An outbreak of Aujeszky's disease occurred in a flock of 160 ewes which had been shorn and housed adjacent to pigs which were excreting Aujeszky's disease virus. The 29 affected sheep developed either the classical 'mad itch' signs associated with Aujeszky's disease in ruminants or signs of encephalitis. Aujeszky's disease virus was isolated from the central nervous system of the affected ewes. Five farm cats also became ill and died. Histological lesions of viral encephalitis were observed in one of the cats and Aujeszky's disease virus was isolated from its brain.