Baba Kama 2:3

If a dog or a goat jumped off a roof and broke utensils, the owner pays full damages because there is a presumption that an animal may cause damage in this manner. If a dog took a cake off the fire to a stack of grain to eat it and a stray coal burned up the grain, the owner pays full damages for the cake and half-damages for the grain.

Baba Kama 2:4

An animal is presumed to cause damage (muad) if its owner was warned for three days; it is no longer presumed to cause damage (tam) if it went three days without incident. This is the opinion of Rabbi Yehuda. Rabbi Meir says that an animal is a muad if the owner was warned three times (even on the same day) and it goes back to being a tam when children can touch the animal without it goring.