Hadith 125

the Messenger of Allah (ﷺ) said, "One day While a man was walking along a road, he became very thirsty. He found a well, so he went down into it and drank. Then he came out and saw a dog panting and eating dirt because of thirst. The man said, “This dog has become as thirsty as I was.” So, he went down into the well, filled his shoes, held them in his mouth, and gave the dog the water to drink, and Allah thanked him and forgave him. People asked: O Messenger of Allah (ﷺ), do we have a reward for treating animals? He (ﷺ) said: For every living thing with a moist liver, there is a reward.

Abu Hurayra (رضي الله عنه)Al-Adab Al-Mufrad 378Adab & Virtues of Mercy towards people