It is narrated from Sayyiduna Zayd bin Khalid al-Juhani (may Allah be pleased with him) that he asked the Messenger of Allah (peace and blessings be upon him) about a stray sheep, and he (peace and blessings be upon him) said: "It is for you, or for your brother, or for the wolf."
And he asked him (peace and blessings be upon him) about a stray camel, and he (peace and blessings be upon him) said: "What have you to do with a stray camel? It has its water-skin and its feet with it; it goes to the water and eats from the trees. I leave it until its owner finds it."
Hadith Referenceالمعجم الكبير للطبراني / باب الزاي / 5234