A model for the induction of Pasteurella multocida type-A pneumonia in pigs.

A model for the induction of pneumonia caused by Pasteurella multocida type-A was developed. Anesthetized pigs were dosed intratracheally with 10(10) colony forming units of P. multocida type-A suspended in a total dose of saline based on the pig's body weight (8 mL/kg). A severe bronchopneumonia was present when the treated pigs were euthanized seven days postinfection. The mean percentage of pneumonic lesions in the treated pigs, as determined by morphometric measurement, was 14.03 +/- 7.01 (X +/- SD). In contrast, in the control pigs, the mean percentage of pneumonic lesions was 0.59 +/- 0.52. For the treated pigs during the period following induction of pneumonia, weight gain and feed intake were reduced significantly (p less than 0.05) compared to the controls. It was shown that severe pneumonia could be induced without the use of other infectious agents, which could potentially confound the experimental model.