Objective: To determine the prevalence of perinuclear antineutrophil cytoplasmic autoantibodies (pANCA) in dogs with confirmed or suspected immune-mediated hemolytic anemia (IMHA) or dogs infected with various vector-borne pathogens, including Rickettsia rickettsii, Bartonella henselae, Bartonella vinsonii subsp berkhoffii, Ehrlichia canis, Borrelia burgdorferi, and Leishmania infantum. Animals: 55 dogs with confirmed or suspected IMHA, 140 dogs seroreactive for vector-borne pathogens, and 62 healthy dogs and dogs seronegative for vector-borne pathogens. Procedures: Samples were allocated to subgroups on the basis of the health status of the dogs and the degree of seroreactivity against various vector-borne pathogens. Serum samples were tested retrospectively via indirect immunofluorescence assay to determine pANCA status. Results: 26 of 55 (47%) dogs with confirmed or suspected IMHA and 67 of 140 (48%) dogs seroreactive for vector-borne pathogens had positive results when tested for pANCA. Serum samples with the highest antibody concentrations against L infantum antigen had the highest proportion (28/43 [65%]) that were positive for pANCA. One of 20 (5%) dogs seronegative for tick-borne pathogens and 8 of 22 (36%) dogs seronegative for L infantum had positive results for pANCA. One of 20 (5%) healthy dogs had serum antibodies against pANCA. Conclusions and Clinical Relevance: pANCA were detected in a high percentage of dogs with IMHA and vector-borne infectious diseases. Therefore, pANCA may be a relatively nonspecific marker for dogs with inflammatory bowel disease, although they could represent a biomarker for immune-mediated diseases and infections.

In this study, the seroprevalence of Toxoplasma (T.) gondii and Bartonella (B.) henselae infection among stray cats in Daejeon City, Korea was surveyed. A total of seven samples were positive (7/118, 5.93%) for T. gondii including three samples from female cats (3/58, 5.2%) and four samples from male cats (4/60, 6.7%). There was no significant difference between the genders. A total 22 samples (22/118, 18.6%) were positive for B. henselae; nine were from females and 13 were from males. There was no significant difference between genders. Nineteen samples had a titer of 1 : 50, two samples had a titer of 1 : 100, and one sample had a titer of 1 : 200. The present study is the first to use serological tests to analyze B. henselae prevalence among stray cats in Korea.