This section is dedicated to animals, and how animals have a healthy attitude toward life. They aren't distressed and don't feel religious guilt.
Whitman begins to show his teeth regarding organized religion, particularly religions that focus on the ideas of guilt, shame, and hatred of the body. He is made "sick" by people "discussing their duty to God."
He also attacks an obsession with owning things and property.
The animals seem to bring him pieces of himself, little reminders of his own heritage and history.
He shares a moment of connection with a majestic stallion, and then he lets the stallion go gallop about. In his imagination, he is galloping faster than the stallion.