Mitral Valve Endocarditis in a Labrador Retriever Caused by anActinomycesSpecies Identified asActinomyces turicensis

Successful treatment of mitral valve endocarditis in a dog associated with 'Actinomyces canis-like' infection

Infective endocarditis, an inflammation of the endocardial surface due to invasion by an infectious agent, is more common in middle sized to large breed dogs. We herein report a case of mitral valve endocarditis in a 9-year-old male-castrated Weimaraner caused by an Actinomyces canis-like bacterium, not previously reported in association with infection in dogs.

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.

DESIGN

Retrospective case series.

ANIMALS

71 dogs with suspected or definite IE.

PROCEDURES

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 AND CLINICAL RELEVANCE

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.

Clinicopathologic findings and outcome in dogs with infective endocarditis: 71 cases (1992–2005)

OBJECTIVES

To evaluate clinical, laboratory, and necropsy findings in dogs with infective endocarditis (IE).

DESIGN

Retrospective case series.

ANIMALS

71 dogs with possible or definite IE.

PROCEDURES

Medical records were reviewed for signalment, clinical features, and results of clinicopathologic testing and diagnostic imaging. Yearly incidence and the effect of variables on survival were determined by use of survival curve analysis.

RESULTS

The overall incidence of IE was 0.05%. Most affected dogs were of large breeds, and > 75% were older than 5 years. The aortic valve was affected in 36 of the 71 (51%) dogs, and the mitral valve was affected in 59%. Lameness caused by immune-mediated polyarthritis, septic arthritis, or peripheral arterial thromboembolism was observed in 53% of the dogs. Neurologic complications were diagnosed in 17 of 71 (24%) dogs. Thromboembolic disease was suspected in 31 of 71 (44%) of dogs. The mortality rate associated with IE was 56%, and median survival time was 54 days. Factors negatively associated with survival included thrombocytopenia, high serum creatinine concentration, renal complications, and thromboembolic complications.

CONCLUSIONS AND CLINICAL RELEVANCE

A diagnosis of IE should be suspected in dogs with fever, systolic or diastolic murmur, and locomotor problems. Dogs with thrombocytopenia, high serum creatinine concentration, thromboembolism, or renal complications may have a shorter survival time.