St. John Bosco had a pet dog in his youth while St. Philip Neri had a cat in his old age. St. Francis of Paola had a pet fish that was cooked one day. So, St. Francis of Paola raised it from the dead by the power of God.
Saint Brigid even tamed animals. Back in her time, the law stated that if a thief was in a Church no-one was allowed to arrest him. One day a group of hunters chased a wild boar into Church and wanted to come in and kill it. The men said that the Church refuge rule did not apply to animals. Saint Brigid said the rule did indeed apply, and so the hunters were forced to leave. She then gave the exhausted boar a drink and it ended up living on her personal farm with the cows she owned.
St. Rocco and St Lazarus the Beggar are pictured with a dog, and St. Anthony of Padua even preached to fish that listened to him. St. Francis negotiated with a wolf and even preached to birds telling them to glorify God. St. Jerome had a lion, and St. Giles had a deer.
As we can see, kindness towards animals and creation is a sign of holiness and respect for God. Whether or not if we can talk with animals like some saints, we all need to show them respect.