Complex developmental cardiovascular anomalies in a Sahiwal calf: a case study on patent ductus arteriosus, defective interatrial septum and arterial malformations.

We document complex developmental anomalies of the cardiovascular system, including patent ductus arteriosus (PDA), additional pulmonary arteries, malformed interatrial septum (IAS), unconventional origin of the common brachiocephalic trunk (CBCT) and subclavian arteries, in a 1-week-old calf of the Indian Sahiwal breed. The PDA was comprised of a cylindrical tube of regular calibre. Additional pulmonary arteries originated from the pulmonary trunk immediately after the bifurcation into the pulmonary arteries. The IAS had the form of an inverted cone frustrum, which projected towards the left atrial chamber, with a wider opening towards the right atrium and a narrow opening towards the left atrium, and contained blood clots. The CBCT originated from the systemic aorta, with the right subclavian artery emerging as its first branch. Microscopic observation revealed that the PDA appeared similar to other blood vessels but with an uneven wall, resulting from a predominant smooth muscle cell population. The PDA had fewer internal cushions and less elasticity, suggesting a lower chance of conversion to the ligamentum arteriosum.