It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "The idea that disease is contagious is not correct. There is no reality to bad omens, and there is no truth to the owl being inauspicious." A man stood up and said: "O Messenger of Allah! Among a hundred camels, if a mangy camel joins them, it makes all of them mangy (and you say that disease is not contagious?)" The Noble Prophet (peace and blessings be upon him) said: "That is destiny; tell me, who afflicted the first camel with mange?"
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 4775
Hadith Gradingحکم دارالسلام:حديث صحيح لغيره، وهذا إسناد ضعيف لضعف أبى جناب