Francis of Assisi is perhaps the most beloved figure in the Church's relationship with animals. He preached to birds, negotiated peace with a wolf, and saw in every creature a reflection of the Creator's love. His Canticle of the Creatures celebrated all living things as "Brother" and "Sister." For Francis, loving animals was not separate from loving God — it was an expression of it.

Pope John Paul II spoke directly and boldly about the moral status of animals in a way no modern pontiff had before him. He affirmed that animals have souls — not rational souls in the human sense, but souls nonetheless — and called on humanity to treat them with love and solidarity. His vision of an integrated creation placed animals firmly within the scope of Catholic moral concern.

Aquinas approached animals through the lens of natural law and virtue ethics. While he held that animals lack rational souls, he argued that cruelty toward animals is sinful — not only because it harms the animal, but because it corrupts the human soul. Compassion, he taught, should extend to all creatures as a matter of moral formation.

A close contemporary of Aquinas and a devoted follower of Francis, Bonaventure saw in creation a kind of divine language. Every animal, he wrote, was a word spoken by God — a trace of the Creator left in the world for us to encounter. To mistreat an animal was, in a sense, to mar that trace. To love one was to love the Author behind it.

Gertrude of Nivelles is one of the Church's most unexpected animal saints. An abbess in Belgium, she became associated over the centuries with cats — and by extension with all small animals kept for companionship. She is a quiet but beloved reminder that the Church's tenderness toward domestic animals runs very, very deep.

St. Roch is perhaps the patron saint most directly associated with dogs. According to tradition, after contracting plague while ministering to the sick, Roch retreated to the forest to die — where a dog found him, licked his wounds, and brought him bread daily until he recovered. He is almost always depicted with a dog at his side, and is invoked for the protection of dogs and their owners.