In plain words
Ignorance is the mark of the animal. “Paśyatīti paśuḥ”, that which sees is a paśu. One whose sight is outward is a paśu, an animal. One whose sight is inward is Paśupati, the Lord of beings. One who does not restrain the senses is an animal. Bad qualities are what an animal is born with. However one tries, they do not change so quickly or leave; nor have animals the capacity to understand when told. For example: though you raise a tiger with great Prema from the time it is small and train it well in good ways and feed it, when it is hungry it will want beef; it will not eat pūrī and potato. That is why it is said “Among creatures, birth as a man is hard to win”: among the beings that are born, man is holy and human birth is rare. Why? By effort man can change the bad saṃskāras he was born with. Man born as a paśu can become Paśupati. An animal is born cruel and dies cruel.