Which theory suits best? It came from Northern European mythology, where the cats influenced the weather and dogs influenced the wind. Which theory suits best? When people thought of cats and dogs fighting in a loud and abrupt manner, it started down pouring. Which theory best suits? In the 17th century, when there was heavy rain, the gutters would be filled with debris, including dead animals. Which theory suits best? In the 1700’s, the roofs were made with sod. The animals would lay on the sod. When there was heavy rainfall, the roof would get wet, causing the animals to fall off the roof. Coming from unknown origin, the idiom “Raining cats and dogs” refers to cats and dogs slipping off of sod roofs when they got wet during heavy rain during the early 1700’s.