EN
The first case of Aujeszky’s disease in cattle was found in an individual farm in 1980, and the next ones in large scale breedings. Since 1985 the number of outbreaks showed an increased tendency. Eight outbreaks of the disease was noted in four farms with one or two recurrences in three of them between 1985—1987. The total number of outbreaks was 11 between 1980—1991. Sick or latently infected pigs were the source of the disease. It was confirmed by serological examinations of pigs kept in close contact with cattle. The disease occurred eight times in the period between November and April indicating to its seasonal appearance. Sensitiveness of cattle to infection was high independently on the age, sex and breed. The shorter incubation period and more acute course of the disease was observed in calves than in adult animals. The morbidity rate did not exceed 30—37% though every case was fatal within 24 hours since the first clinical signs. Cerebral signs (excitement), significant pruritus of the head and neck, anorexia, salivation, meteorism, dyspnoe, sweating, mooings and paresis and paralysis before death were observed. Gross lesions were poorly marked, except for local skin lesions. Histopathologically non purulent lymphocytar meningoencephalitis was predominant. From the brain of dead animals Aujeszky’s disease virus was isolated, however, serological test performed in sick or healthy animals were negative.