Aortic endocarditis in the dog: the vegetation on echocardiography
7-year-old, 25 kg crossbred dog with fever, lethargy, shifting lameness and a new diastolic murmur over the left heart base. Right parasternal long-axis echocardiogram (outflow tract view):
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An irregular hyperechoic lesion is seen on the aortic valve. Which statement about its interpretation is correct?
chevron_right Show answer and explanation
A. It is typical of myxomatous aortic degeneration
Myxomatous degeneration mainly affects the mitral and tricuspid valves; aortic involvement is rare and mild. An irregular mass on the aortic valve is not explained that way.
B. Negative blood cultures would rule it out
Negative blood cultures are common in endocarditis (prior antibiotics, Bartonella, fastidious organisms). They do not rule out the diagnosis.
C. It strongly suggests infective endocarditis
Correct. An irregular, hyperechoic and often oscillating mass on the aortic valve, with a new diastolic murmur and fever, is highly suggestive of infective endocarditis; the vegetation is a major echocardiographic criterion. Take serial blood cultures before starting antibiotics.
D. It corresponds to normal valve nodules
Normal aortic cusp nodules are tiny, smooth and symmetrical. They do not form an irregular mass or come with a new diastolic murmur.
lightbulb Key takeaway
A vegetation on the aortic or mitral valve is a major criterion for endocarditis. Aortic involvement carries the worst prognosis because of the aortic regurgitation and heart failure it causes; take at least three blood cultures before antibiotics and, if negative, think of Bartonella.
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Updated: November 1, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.