[Respiratory diseases in poultry caused by viruses--occurrence and diagnosis (author's transl)].

The highly intensive conditions, that economic necessity has forced upon the poultry industry, have resulted in strongly changed environmental conditions and management which combined with the use of a constantly increasing number of live vaccines has highly complicated clearing up the etiology in diseased flocks. This is true not least as far as respiratory diseases concerns, which thereby often run an atypical course. A review, however, not complete, is given of the occurrence and diagnostic procedures in respiratory diseases caused by viruses, the greatest importance attached to infections caused by adeno- and infectious bronchitis virus.