Evaluation of the relationship between causative organisms and clinical characteristics of infective endocarditis in dogs: 71 cases (1992-2005).
OBJECTIVE
To evaluate microbiologic findings in dogs with infective endocarditis (IE) and determine whether there were differences in clinical features of disease caused by different groups of infective agents.


METHODS
Retrospective case series.


METHODS
71 dogs with suspected or definite IE.


METHODS
Medical records were reviewed for results of bacterial culture and susceptibility testing, serologic assays for vector-borne disease, and PCR testing on vegetative growths. Cases were grouped by causative organism and relationships among infectious agent group, and various hematologic, biochemical, and clinical variables were determined. Survival analyses were used to determine associations between infecting organisms and outcome.


RESULTS
Causative bacteria were identified in 41 of 71 (58%) dogs. Gram-positive cocci were the causative agents in most (21/41; 51%) infections, with Streptococcus canis associated with 24% of infections. Gram-negative organisms were detected in 9 of the 41 (22%) dogs. Infection with Bartonella spp was detected in 6 of 31 (19%) dogs with negative results for microbial growth on blood culture. Aortic valve involvement and congestive heart failure were more frequent in dogs with endocarditis from Bartonella spp infection, and those dogs were more likely to be afebrile. Infection with Bartonella spp was negatively correlated with survival. Mitral valve involvement and polyarthritis were more frequent in dogs with streptococcal endocarditis.


CONCLUSIONS
Streptococci were the most common cause of IE and were more likely to infect the mitral valve and be associated with polyarthritis. Dogs with IE secondary to Bartonella spp infection were often afebrile, more likely to develop congestive heart failure, rarely had mitral valve involvement, and had shorter survival times.
Sykes
Jane E
JE
Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA.
Kittleson
Mark D
MD
Pesavento
Patricia A
PA
Byrne
Barbara A
BA
MacDonald
Kristin A
KA
Chomel
Bruno B
BB
D000818:Animals; D001473:Bartonella / Q000187:drug effects / Q000302:isolation & purification; D001474:Bartonella Infections / Q000382:microbiology / Q000401:mortality / Q000473:pathology / Q000662:veterinary*; D004283:Dog Diseases / Q000382:microbiology* / Q000401:mortality / Q000473:pathology; D004285:Dogs; D004697:Endocarditis, Bacterial / Q000382:microbiology / Q000401:mortality / Q000473:pathology / Q000662:veterinary*; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology / Q000401:mortality / Q000473:pathology / Q000662:veterinary*; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology / Q000401:mortality / Q000473:pathology / Q000662:veterinary*; D008297:Male; D012189:Retrospective Studies; D013291:Streptococcus / Q000187:drug effects / Q000302:isolation & purification; D016019:Survival Analysis