Dog

Overview
Dogs are domestic animals that can be purchased at the Animal Store for 3,000 coins. They have no purpose except for accompanying you. However, if you herd animals, the dog will bark at the animals, making them go where you pointed them. This is just a feature, as even without a dog, you can herd animals

Money
Dogs have no product to sell, so there is nothing here.

Costs
Dogs need a animal feeder for 3000, and you have to periodically restock the feeder for 450 coins per box of Animal Food, or make them via Animal Food Factory.

Free Dog
Dogs can sometimes be found ambling around your farm, and if you interact with it, there will be a cutscene showing you petting the dog, and the words, 'You found a Dog!'. The dog is free, so it is best to wait until this happens rather than buying a dog itself from the Animal Store for 3000 coins.