Excessive washing and harsh shampoos both lead to dry, irritated skin, though. Dogs should be bathed as infrequently as possible as long as they're clean, healthy-looking and smelling fresh. Any shampoo you use on a dog should be gentle and nonirritating. Also, always use a canine conditioner -- never a human one -- after every bath.
Using People Shampoo
Most shampoos made for humans contain ingredients that are too harsh for sensitive doggy skin. Their use is likely to cause dry, itchy skin that's stripped of its natural protective and moisturizing oils. This is true of most people products with labels that claim the shampoos are "gentle" or "moisturizing." However, there's one exception: Baby shampoo for people is fine to use on your dog. It actually is gentle, nondrying and moisturizing enough for regularly washing a canine companion. Still, limit baths to no more than every few weeks or months.
Other Shampoo Options
Human baby shampoo is a good pick for regular bathing. However, mild soap-free canine shampoos are just as suitable for consistent use. Opting for hypoallergenic products without soap, detergent, fragrances and dyes is usually best, as these are typically the least irritating. Shampoos containing soap, whiteners or bluing agents should be reserved for occasional use when your dog is really dirty.