A horse owner presented with tricuspid valve endocarditis, a rare and severe infection. The patient's symptoms and history of animal contact prompted investigation for zoonotic pathogens. Diagnosis was confirmed through blood cultures identifying Streptococcus equi subsp. zooepidemicus (SESZ). This bacterium is a group C streptococcus primarily associated with horses and other animals, uncommonly causing human infections, especially infective endocarditis. The case highlights the importance of considering zoonotic transmission in patients with relevant exposures and atypical presentations. Prompt identification of SESZ is crucial for appropriate treatment and favorable outcomes in such rare cases.
Key note: Zoonotic pathogens, particularly those from animal contact, should be considered in endocarditis cases with unusual epidemiology.