Persistent left cranial vena cava and absent right cranial vena cava in a German shepherd dog with multiple congenital cardiovascular defects

Authors: Vila BCP, Wolf M, Garcia M, da Costa BN, Froes TR, Sousa MG
Publication: Australian Veterinary Practitioner, Volume 51, Issue 2, pp 114-124, Jun 2021
Publisher: Australian Veterinary Association

Animal type: Dog
Subject Terms: Cardiology, Clinical examination, Congenital disease
Article class: Clinical Report

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Abstract:

A 4-month-old male German shepherd dog was referred for investigation of lethargy and exercise intolerance, as well as a grade V/VI systolic murmur. Echocardiography revealed aortic and subaortic stenosis, post-stenotic aortic dilation and aortic insufficiency. The mitral valve was thickened with mild regurgitation. Coronary sinus dilation and an anechoic cystic structure in the region of the right atrium were also noted. Over two months, the dog developed left ventricular hypertrophy, systolic anterior motion of the anterior mitral leaflet, and aortic flow velocity increased. Computed tomography confirmed persistence of the left cranial vena cava and absence of the right cranial vena cava, with the costocervical and azygos veins terminating in the region of the right atrium, producing an atrial aneurysm. The dog has since been evaluated at 3-monthly intervals. Although exercise intolerance partially resolved after atenolol therapy, aortic velocity and pressure gradient have progressively increased, and concentric left ventricular hypertrophy has developed.

This is the first case report of a dog with combined valvular aortic and subaortic stenosis, absent right cranial vena cava, persistent left cranial vena cava, mitral valve dysplasia and right atrial aneurysm. Although congenital cardiac diseases were identified on echocardiography, a contrast computed tomography was needed to clarify the multiple complex cardiovascular abnormalities present.

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