[Clinical and microbiological investigations of atrophic rhinitis of Upper Austrian swine herds]

The aim of this study was to determine the distribution of the progressive and non-progressive atrophic rhinitis of Upper Austrian swine herds. Further on the resistance pattern of the pathogens involved to chemotherapeutics was tested. In the period of May 1993 to June 1996 a total of 56 Upper Austrian swine herds were examined and on the occasion of the animal herd health management 997 nasal swab-samples of young pigs taken. The area of this investigation included 14 Upper Austrian districts and the herds examined were divided into 3 types. Type 1 were swine herds of the swine breeding association (SZV), type 2 piglet producing farms (FP) and type 3 closed swine herds (GB). Sucking- and weaning piglets aged from 4 to 10 weeks were selected for these examinations. On the average 10 nasal swab-samples (2 swabs per animal) per herd were taken, microbiologically examined and the toxin by means of ELISA-tests determined. In terms of resistance testing (antibiogram) 20 different chemotherapeutics, which consisted of 11 different groups of drugs, were used. As a result of 997 nasal swab-samples examined, 304 (30.5%) P. m., 111 (11.1%) tox. P. m. and 35 (3.5%) B. b. were isolated. 50% of the Upper Austrian swine herds showed PAR by means of microbiological examination and ELISA-tests as well. The resistance pattern of P. m. and B. b. exhibited significant differences. Penicillin and lincospectin were highly resistant concerning isolates of B. b., but were highly sensitive for P. m. Enrofloxacin turned out as the most effective drug to the P. m.-toxin-negative- and B. b.-strains tested, because no resistance was observed. Finally efficient PAR control programmes of swine herds belonging to the Upper Austrian swine herd health service are described.