nedarim 65

dead snakes and dogs who allow one to enter a house.

and the live rabbit who made the elders sit on the floor in mourning.

Vowing not to enter a house because of a snake or dog inside. Later in the page there is a story of King Zedikah who saw Nebuchanezzer eat a live rabbit. Zedikiah had to swear an oath not to tell anyone. When Nebuchanezzer's oppression got tougher, he told the members of the Sanhedrin. Nebuchanezzer was furious as vows can only be cancelled in the presence of the one who initiated it. The Sanhedrin admitted their error and began mourning that became the destruction of the Temple.

pesachim 45

what falls in the cracks couldn't feed a dog.

eruvin 86

dog barking at the door is either saying
COME IN!
or
GO AWAY!
depending if it a male or female dog.

but for water there is no real barrier

(this page discusses if someone leaves their home on shabbat whether or not their absence affects the neighbours in the courtyard and if they are still needed to make the eruv. it is assumed that if they are visiting their daughter, they won't be returning. but if they are visiting their son, their daughter-in-law may not want them, and she will bark, so they will have to leave and return home during shabbat. the talmud quotes a saying "if a dog barks you can enter; if a female dog bark, leave"
Also on the page is a cistern that is shared between two courtyards, and devising a type of partition, while acknowledging that water intermingles and there is no real barrier)