Infective endocarditis (IE) is a bacterial disease that commonly occurs in dogs. Difficulty in diagnosis and underreporting of IE in dogs contribute to the reported low prevalence rate of the disease. The mitral and aortic valves are the worst affected by IE. Common causative microbial agents include Staphylococcus spp, Streptococcus spp, Escherichia coli, and Bartonella spp. Congestive heart failure, immune-mediated disease, and thromboembolism are the major complications of IE. Diagnosis of IE by echocardiography and long-term treatment with broad-spectrum antibiotics may contribute to the timely detection and treatment of the disease.