Temporal course of experimentally induced enzootic pneumonia in SPF-swine
Bertschinger, H.U.; Keller, H.; Lohrer, A.; Wegmann, W.
Schweizer Archiv für Tierheilkunde 114(2): 107-118
1972
ISSN/ISBN: 0036-7281 PMID: 5060783 Document Number: 49712
Some workers consider the absence of macroscopically recognizable lung lesions in a representative number of slaughter pigs as the deciding criterion in the recognition of a herd free from enzootic pneumonia. It also represents an important supervision method in the Swiss pig health service. Pathogen-free pigs were infected with two mycoplasma strains recently isolated from outbreaks of enzootic pneumonia. With strain M, coughing commenced 18 days after inocluation, affected all animals between the 24th and 40th day, and disappeared by the 60th day. Strain V caused coughing by the 16th day, which disappeared by the 50th day. Two months after inoculation no gross P.M. lesions could be seen, except that in some lungs there were some small, uncharacteristic scars. It is concluded that the absence of macroscopic lung changes at slaughter does not necessarily mean the absence of enzootic pneumonia in SPF pigs.