[Prospective study of the presence of atrophic rhinitis and AR-pathogenic Bordetella bronchiseptica and Pasteurella multocida bacteria in piglets of health-certified pig-breeding farms].

Two hundred eight-week-old piglets from 20 pig-breeding farms, on which the clinical findings did not provide any justification for suspecting the presence of atrophic rhinitis (AR), were examined for this disease. Clinical parameters were brachygnathia superior (BS) and snout-distorsion (KD). Piglets with BS (n = 48) were observed on 13 farms and with KD on 8 farms. Morbid anatomical parameters were deviation of the nasal septum (SD) and atrophy of the ventral conchae (AVC). SD was observed in 76 piglets from 17 farms. Piglets with AVC gradation greater than or equal to 1 were recorded on 20 farms and with grade greater than or equal to 3 on 12 farms. The average gradation of AVC over all farms was 1.3 varying from 0.2 to 2.9. Bacteriological studies were done in the piglets for Bordetella bronchiseptica (BB) and AR pathogen Pasteurella multocida (PM+). The score of AVC showed a significant increase on farms on which infections with PM+ and BB was present. It is indicated that pig-herds with an average AVC gradation smaller than 0.7 do have a chance of less than 10% to be infected with PM+. BB was isolated from 52 piglets, from the nose in 49 cases and from the trachea in 27 cases respectively. PM was isolated from 67 piglets. Examination by equine blood agar showed that 15 piglets were positive for PM in the nose, 32 animals being found to be positive for PM by examination using mice. When mice were used in studies of the tonsils, 59 were found to be positive for PM. Of 45 piglets infected with type D, 16 were found te be PM+ following the guinea-pig skin test, the results being regarded as doubtful in two cases. Epidemiological studies for BB and PM+ on 117 breeding-farms in the Province of Overijssel showed that 92% of these farms were infected with BB and 28% with PM+. To be able to qualify breeding-farms as 'not being suspected of AR' concentrated clinical, pathological and bacteriological studies are required.