Submitted to: Research Workers in Animal Diseases Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 8/31/1995
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: The pathogenicity of a low passage Pasteurella multocida (PmA:1) duck challenge culture (4.4 X 10**9 CFU/ml) and a bovine PmA:3 culture (3.8 X 10**9CFU/ml) were compared in the goat. One ml of each Pm strain was injected transthoraciclly into six susceptible weanling goats. The goats were observed for 4 days, then were euthanatized and necropsied. There were no significant differences between the two groups in mean volume of pneumonic tissue at the injection site: duck, 9.4 cm**3 (+/- 4.98SD), and calf, 15.2cm**3(+/- 9.46SD). No significant differences were noted in mean daily rectal temperatures, mean total WBC counts, hemoglobin, packed cell volume, serum haptoglobin, or indirect hemagglutinating antibody titers on days 0 and 3. At necropsy, Pm cultures were recovered from the following tissues, and locations: in the duck group, nasal, 2/6; pharynx, 5/6; proximal trachea, 3/6; distal trachea, 6/6; thoracic fluid, 4/6; right lung, 6/6; kidney, 1/6; liver, 1/6; spleen, 1/6; and thoracic lymph node, 0/6; and in the calf group, nasal, 4/6; pharynx, 2/6; proximal trachea, 5/6; distal trachea, 2/6; thoracic fluid, 0/6; right lung, 6/6; kidney, 0/6; liver, 1/6; spleen, 0/6; and thoracic lymph node, 1/6. The mean Pm bacterial titers at the injection site of the right lung were, 7.37 X 10**7 CFU/ml for the duck group, and 3.5 X 10**7 CFU/ml for the calf group. Histopathologically, similar lesions of exudative necrotic pneumonia were present in both groups. It was concluded that at the concentrations given, the duck Pm strain and the calf Pm strain were of similar pathogenicity in the goat.