Isolation and characterization of Bordetella bronchiseptica from cats in southern Louisiana

The role of Bordetella bronchiseptica in respiratory disease of domestic cats is currently being explored. Clinical and experimental studies in the United Kingdom have shown Bordetella bronchiseptica to be a primary respiratory pathogen in cats; similar studies in the United States are limited. The purpose of this study is to report on the isolation, seroprevalence, and partial characterization of Bordetella bronchiseptica from shelter cats in southern Louisiana. A total of 614 cats from four local shelters were studied. All cats appeared to be asymptomatic for signs of respiratory disease. Bordetella bronchiseptica was isolated in 19/614 (3.1%) cats by oropharyngeal swab and in 6/614 cats by bronchial lavage. Using an antibody capture ELISA method, 148/614 (24.1%) cats were seropositive for Bordetella bronchiseptica. The 25 isolates of Bordetella bronchiseptica were further characterized by ribotype analysis, and a total of 17 different ribotypes were identified. Specific pathogen-free kittens were experimentally infected with five of the isolates, and four of the five isolates induced clinical signs typical of feline bordetellosis. It is concluded that Bordetella bronchiseptica is present in the cat population in southern Louisiana, the organism can be isolated from asymptomatic cats, some of these isolates can produce disease in specific pathogen-free kittens, and that Bordetella bronchiseptica isolates from cats in a relatively small geographic area are genetically diverse. This and other studies indicate that Bordetella bronchiseptica should be considered in cases of feline respiratory disease.