Dogs in the wild don’t need baths. Why do our dogs? Well, they don’t need baths, but if they want to live in our homes, and sometimes even sleep in our beds, they have to look and smell cleaner than dogs normally do. Shampoos can be formulated for general cleaning, or for specific purposes, such as killing fleas or soothing irritated skin. Since there are more effective methods of accomplishing both of these tasks, we’ll focus only on the sudsy substances that do the best job of cleaning your dog’s hair, without irritating his skin, or making him sick.