The equine neonatal cardiovascular system

Fetal circulation, which allows for transport of oxygen and nutrition from the placenta, transitions at birth to neonatal circulation, where the lungs are no longer bypassed. Because of this change and the immaturity of the neonate's body systems, neonatal cardiovascular physiology is different from adult physiology, and this must be considered during the physical examination and assessment of the foal. The foal's cardiovascular system is more sensitive to the effects of sedation and systemic disease, and these can initially be overlooked but have an important clinical impact. An array of congenital cardiac anomalies are described in foals with a range of clinical consequences, although these are rare. This article summarises key features in foals to help detect, diagnose, treat and prognosticate cardiovascular pathology in foals.