Fear Allah regarding these dumb animals. Ride them when they are fit, and eat them when they are fit
Authentic hadithعن سهل بن عمرو رضي الله عنه قال: مرَّ رسول الله صلى الله عليه وسلم ببعير قد لَحِق ظَهْرُه ببَطْنِهِ، فقال: «اتقوا الله في هذه البهائم المُعْجَمة، فاركَبُوها صالحة، وكُلُوها صالحة».
Sahl ibn ‘Amr (may Allah be pleased with him) reported that the Messenger of Allah (may Allah's peace and blessings be upon him) passed by a camel whose stomach touched to its back, so he said: “Fear Allah regarding these dumb animals. Ride them when they are fit (for riding), and eat them when they are fit (for eating).”
Explanation
The Prophet (may Allah's peace and blessings be upon him) saw a camel whose belly was touched to its back because of starvation, so he ordered kindness and gentleness in treating animals. It is incumbent upon a person to be kind to animals by not overburdening them beyond their ability, and not neglecting to feed them sufficient food and drink. So, when one rides them, let them be fit for riding, and when eats them, let them be fit for eating.
Source · Narrated by Abu Daoud - Narrated by Ahmad
From the Hadith Encyclopedia (hadeethenc.com).