Pasteurella spp. infections of the lower respiratory tract in dogs and cats

Đurđa Slavić, Murray Hazlett

Animal Health Laboratory, University of Guelph, Guelph, ON

AHL Newsletter 2020;24(4):20.

From mid-2007 to Sept 2020, Pasteurella spp. were isolated from respiratory tract samples of 18 dogs and 25 cats (Table 1).  Only cases that had accompanying pathology testing were included in this analysis.  Most of the samples processed for bacteriology were lung tissue, but there were also some swabs and lavage samples.  In only 5 cases (2 cats and 3 dogs), species identification of Pasteurella could not be confirmed and these were reported only to the genus level.  When identified to the species level, as expected, P. multocida was predominantly isolated from cats (15), followed by P. dagmatis (8).  In contrast, P. canis (9) was the most frequent isolate from dogs, followed by P. dagmatis (4).  Other Pasteurella spp. were isolated sporadically from both dogs and cats (Table 1).  In a few cases, more than one species of Pasteurella was isolated from dogs (2 cases) and cats (3 cases).  Histologically, pneumonia and septicemia were the most commonly-diagnosed conditions (Fig. 1).    

Pasteurella spp. are common members of bacterial flora of upper respiratory tract and oral cavity of dogs and cats.  They usually cause opportunistic infections in their hosts, frequently in combination with other pathogens.  Pasteurella spp., predominantly P. multocida, are also implicated in bite wound infections in other animals, including humans.  In addition, P. multocida occasionally causes primary infections such as fowl cholera in poultry and hemorrhagic septicemia in swine, cattle, and water buffalo.   AHL

 Pasteurella species



Pasteurella spp.



Pasteurella canis



Pasteurella dagmatis



Pasteurella multocida



Pasteurella oralis



Pasteurella stomatis







Table 1. Isolates of Pasteurella spp. from lower respiratory tract of canine and feline autopsy cases, 2007-2020.

       - (2+) in a 12-month-old cat. C. Histology from B, showing large outpouring of neutrophils overlying pleural surface. (H&E

Figure 1. A. Pasteurella dagmatis pleuropneumonia in a 6-month-old cat. A pure culture was isolated.
B. Pleuropneumonia associated with Pasteurella oralis (3+) and Salmonella S. I:4,5,12:i:- (2+) in a 12-month-old cat. C. Histology from B, showing large outpouring of neutrophils overlying pleural surface. (H&E)