Anatomical observations about the closure of the ductus venosus in the dog (Canis familiaris).

The observation of the anatomical closure of ductus venosus was carried out in 108 dogs (62 females and 46 males) with age varying between 3 hours and 21 days old. We have observed that within 2 days old, the ductus venosus was found pervious in 100% of the animals sacrified; 3 days old, in 81% of the animals; 4 days old, in 62% of pups; 5 days old, in 25% and over 6 days old, the ductus venosus was anatomical closed in 100% of the animals. We have also observed that the closure starts within 48 hours on the caudal vena cava caudal side.