Dogs used to urinate and come and go in the mosque during the time of the Messenger of Allah ﷺ, and they did not sprinkle water over any of that.
كانت الكلاب تبول وتقبل وتدبر في المسجد في زمان رسول الله ﷺ، فلم يكونوا يرشون شيئا من ذلك.
Bukhari narrated it (174), except that he said, Ahmad bin Shabib said, my father narrated to us, from Yunus, from Ibn Shihab, who said, Hamza bin Abdullah told me, from his father... and he mentioned the hadith.Abu Dawud added (382), "I used to sleep in the masjid during the time of the Messenger of Allah ﷺ, and I was a young unmarried man, and dogs would urinate and come and go in the masjid, yet they did not sprinkle anything because of that."The scholars said, this is to be understood as referring to the early period of Islam, when the masjids had no doors, then we were commanded to honor the masjids, purify them, and put doors on them.