Imaging diagnosis--tricuspid atresia in an alpaca

Postmortem magnetic resonance imaging findings of tricuspid atresia with ventricular and atrial septal defects and subvalvular pulmonic stenosis in a Japanese native Noma horse

The necropsy of a 2-day-old Noma horse that died of weakness showed an enlarged cardiac base and a narrow cardiac apex, suggesting cardiac malformation. The excised heart underwent imaging to investigate its luminal structure. On three-dimensional magnetic resonance imaging, the right atrium and right ventricle were discontinuous. The right atrium communicated with the left atrium and the left ventricle communicated with the right ventricle. The lumen narrowed near the pulmonary artery valve. Since the same findings were observed on gross examination, the foal was diagnosed with tricuspid atresia with ventricular and atrial septal defects, along with subvalvular pulmonic stenosis.

Tricuspid atresia with atrial and ventricular septal defects in a kitten

A 45-days-old mixed-breed female cat was referred to a veterinary specialty hospital for evaluation due to poor general condition, dyspnea of possible cardiac origin, and a heart murmur. The results of the physical examination, thoracic radiography, and echocardiography led to a diagnosis of hypotrophy of the right ventricle, tricuspid atresia, and atrial septal defect. Cardiovascular pathological findings confirmed the clinical diagnosis in addition to the observation of a ventricular septal defect. To the authors' knowledge, this is the first report of tricuspid atresia with atrial septal defect and ventricular septal defect in a cat.

Gross anatomy of the heart of the alpaca (Vicugna pacos, Linnaeus 1758)

The available information about anatomical characteristics of the cardiovascular system of the alpaca (Vicugna pacos, Linnaeus 1758) is scarce. The general objective of this work was to describe its heart anatomy. We dissected six adult animals and five neonates. The heart of the alpaca was located in the middle mediastinum, with a craniocaudal extension from the third to the sixth rib. No ligament that connected the fibrous pericardium to the sternum or to the diaphragm was detected. In the right atrium, there was a developed crista terminalis and small pectinate muscles. In the right ventricle, the septomarginal trabecula was very large. From the proximities of the interventricular septum arose small septomarginal trabeculae that ended in carnous trabeculae of the septal wall. The left atrium included little developed pectinate muscles. On the left ventricle, both papillary muscles were bilobed. Two left septomarginal trabeculas were detected in this ventricle. The left subclavian artery was originated from the aortic arch separately from the brachiocephalic trunk, and bicarotid trunk was present. The other branches of the subclavian artery were similar to the domestic ruminants. The arterial supply of the heart was of the right type. In conclusion, the heart anatomy of alpaca and the irrigation of thoracic cavity were more similar to those of old world camels and different from domestic ruminants.

Common Arterial Trunk in a 3-Day-Old Alpaca Cria

A 3-day-old alpaca cria presented for progressive weakness and dyspnea since birth. Complete bloodwork, thoracic radiographs, and endoscopic examination of the nasal passages and distal trachea revealed no significant findings. Echocardiogram and contrast study revealed a single artery overriding a large ventricular septal defect (VSD). A small atrial septal defect or patent foramen ovale was also noted. Color flow Doppler and an agitated saline contrast study revealed bidirectional but primarily right to left flow through the VSD and bidirectional shunting through the atrial defect. Differential diagnosis based on echocardiographic findings included common arterial trunk, Tetralogy of Fallot, and pulmonary atresia with a VSD. Postmortem examination revealed a large common arterial trunk with a quadricuspid valve overriding a VSD. Additionally, defect in the atrial septum was determined to be a patent foramen ovale. A single pulmonary trunk arose from the common arterial trunk and bifurcated to the left and right pulmonary artery, consistent with a Collet and Edwards' type I common arterial trunk with aortic predominance. Although uncommon, congenital cardiac defects should be considered in animals presenting with clinical signs of hypoxemia, dyspnea, or failure to thrive.

Ventricular septal defect and double-chambered right ventricle in an alpaca

A 20-month-old male alpaca was referred for evaluation of a cardiac murmur evident since birth. Echocardiography identified a ventricular septal defect (VSD) and a fibro-muscular band causing a stenosis of the right ventricular outflow tract. Right ventricular catheterization and selective angiography confirmed the diagnosis of VSD and double-chambered right ventricle with bidirectional shunting.