EXPRESS: Ebstein’s anomaly in two cats, including a rare variant with partial anterior tricuspid leaflet displacement

Case Summary Case 1: A 5‑month‑old male Ragdoll cat demonstrated acute anorexia, mild tachypnoea, and dull mentation. Cardiac auscultation revealed a grade 4/6 systolic murmur at the right cardiac apex. Echocardiography revealed marked right atrial enlargement, apical displacement of the tricuspid valve leaflets, and partial atrialization of the right ventricle, which were consistent with Ebstein’s anomaly (EA). Medical treatment was discontinued at the owner's request after 1 month. The cat remained relatively stable for several months but died from heart failure 16 months after the initial diagnosis. Necropsy confirmed apical displacement of the tricuspid septal leaflet and partial displacement of the anterior leaflet. Case 2: A 4-year-6-month-old spayed female domestic cat presented with lethargy, hyporexia, and acute tachypnea. Echocardiography revealed marked right atrial enlargement, apical displacement of the tricuspid septal leaflet, severe tricuspid regurgitation (peak regurgitant velocity 2.8 m/s), and partial atrialization of the right ventricle, which confirmed the diagnosis of EA. Clinical signs improved following medical treatment; however, the cat died at home 1 month later. Necropsy was declined, and the cause of death remained undetermined. Relevance and Novel Information This report describes two cases of feline EA and documents a rare morphological variant involving partial displacement of the anterior tricuspid leaflet. These findings expand current knowledge of anatomical variation in feline EA and may have implications for diagnosis and interpretation of echocardiographic findings.