"I was a companion rider on a female donkey with Al-Fadl. We came while the Prophet and his Companions were performing Salat at Mina." He said: "We dismounted from it and joined the row. The donkey then passed in front of them, and this did not invalidate their Salat."
Jami` at-Tirmidhi Book 2, Hadith 189
← Previous Hadith that Allah's Messenger said: "If the one who passed in front of the person performing Salat knew what he was doing, then for him to stop (and wait for forty) would be better for him than to pass in front of him."

Jami` at-Tirmidhi Book 2, Hadith 188 Next Hadith → Allah's Messenger said: "When a man performs Salat, and there is nothing in front of him like the post of a saddle, or a camel saddle, then his Salat is severed by (passing of) a black dog, a woman, and a donkey." It was said to Abu Dharr: "What is the problem with the black dog rather than the red or white one?" He said: "O my nephew! I asked Allah's Messenger just as you have asked me. He said: 'The black dog is a Shaitan (devil).'"

Jami` at-Tirmidhi Book 2, Hadith 190