Patent Ductus Arteriosus (PDA) L to R

PDA (Patent Ductus Arteriosus) L to R: Papillon, 6 weeks old, weighing 550 g, The patient was much smaller than the littermates. A machinery murmur was present (maximum underneath left shoulder).
Note that this puppy with L-R shunt has a normal systolic gradient across the shunt but the diastolic gradient is quite low (sign of a large shunt). The pda can be seen on CDI as well as on B-mode images. This puppy went to surgery.