Intrapulmonary arteriovenous anastomoses are common in clinically healthy dogs and may cause delayed left ventricular microbubble appearance during saline contrast echocardiography, potentially mimicking intracardiac right-to-left shunts. Oxygen supplementation significantly decreased IPAVA flow, suggesting that these physiological shunts may be dynamically regulated by inspired oxygen levels.
Cho et al. (Thu,) studied this question.