OCCURRENCE OF SOME VIRUSES AND BACTERIA INVOLVED IN RESPIRATORY-DISEASES OF RUMINANTS IN HUNGARY

Serological surveys, virological and bacteriological investigations we re carried out on large populations of lambs and calves kept in intens ive fattening units on Hungarian large-scale farms, in order to study the occurrence of viruses and bacteria involved in the respiratory dis ease complex. The investigations were carried out in stocks where 5-20 % of the young animals succumbed to acute or chronic pneumonia every y ear. Serological surveys revealed that seropositivity to bovine adenov irus type 2 (BAV-2) and parainfluenza type 3 (PI-3) were the most wide spread viral infections both in cattle and sheep (BAV-2: 56% and 88%, PI-3: 76% and 41%, respectively). Antibodies against infectious bovine rhinotracheitis virus (BHV-1) were also found in a high proportion (4 5%) of sera of 3-8 month old calves, while in 2-6 month old lambs ovin e adenovirus 1 (OAV-1) was the third most frequent virus (22%). Bacter iological investigations demonstrated secondary infections caused by d ifferent Pasteurella haemolytica and Pasteurella multocida serotypes i n most cases. In cattle herds P. multocida A proved to be the predomin ant bacterium: it was isolated in each herd examined, while P. haemoly tica Al strains were isolated in 7 and Haemophilus somnus in 2 out of 13 herds. In sheep flocks P. haemolytica was the most frequent species isolated, 10 serotypes were cultured from pneumonic sheep but serotyp es A2, A1 and A8 were the dominant ones.