Quadricuspid aortic valve (QAV) is a rare congenital heart condition in which the aortic valve is comprised of four, rather than three, sinuses and cusps. The clinical significance of QAV is unclear; it is diagnosed most frequently in humans and has not been reported in cattle. QAV was identified in three female Holstein cattle at necropsy for unrelated clinical conditions. Although heart murmurs were identified on clinical examination, no animal had heart failure. In all three cases the non-coronary cusp of the aortic valve was comprised of two separate cusps, resulting in a quadricuspid valve. Histological examination of the abnormal valves did not reveal consistent significant microscopic lesions. The clinicopathological consequences, genetic basis and incidence of QAV in cattle are unclear; however, veterinarians and pathologists should be aware of this condition as a possible differential diagnosis in cattle with heart murmurs.

Aortic valve

Cattle

Congenital anomaly

Heart

Holstein

Quadricuspid

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