Narrated Abu Huraira
Allah's Messenger (ﷺ) said, "While a man was walking he felt thirsty and went down a well and drank water from it. On coming out of it, he saw a dog panting and eating mud because of excessive thirst. The man said, 'This (dog) is suffering from the same problem as that of mine. So he (went down the well), filled his shoe with water, caught hold of it with his teeth and climbed up and watered the dog. Allah thanked him for his (good) deed and forgave him." The people asked, "O Allah's Messenger (ﷺ)! Is there a reward for us in serving (the) animals?" He replied, "Yes, there is a reward for serving any animate."
Narrated Asma' bint Abi Bakr
The Prophet (ﷺ) prayed the eclipse prayer, and then said, "Hell was displayed so close that I said, 'O my Lord ! Am I going to be one of its inhabitants?"' Suddenly he saw a woman. I think he said, who was being scratched by a cat. He said, "What is wrong with her?" He was told, "She had imprisoned it (i.e. the cat) till it died of hunger."
Narrated `Abdullah bin `Umar
Allah's Messenger (ﷺ) said, "A woman was tortured and was put in Hell because of a cat which she had kept locked till it died of hunger." Allah's Messenger (ﷺ) further said, (Allah knows better) Allah said (to the woman), 'You neither fed it nor watered when you locked it up, nor did you set it free to eat the insects of the earth."