**7. Conclusions**

In this chapter, we describe the embryology, physiological function and congenital diseases associated with pulmonary veins. The developmental process of the cardiovascular system is complicated, and every step is crucial. The CTS, TAPVC and PAPVC are rare congenital cardiovascular diseases in human and other animals, and can be asymptomatic or life-threatening. The improvement of advance imaging modules helps in diagnosing these abnormalities, particularly those have multiple concurrent developmental diseases. Knowledges regarding to the treatment intervention in the veterinary medicine is much less than the human medicine, further studies are welcome to provide more information.
