Sometimes. It depends on if there are chemicals or pesticides added to the shampoo. The main difference in animal and human shampoo is the pH balance. Human shampoo is usually more acidic, and can irritate the thin-layered skin of animals like cats and dogs. Most dog/shampoos listed as "gentle", "everyday" or even "shed control" use common "human" shampoo ingredients like Panthenol-D, Sodium chloride, Sodium lauryl Sulfate, parabens, and Cocamidopropyl. In fact, Cocamidopropyl is an ingredient in Johnson & Johnson baby shampoo and is listed in most Pro-Pet shampoos! I've used their shed control on myself because it has Omega 3 Fatty Acids, which is supposed to be really good for hair, and it's a lot less expensive than some human shampoo. Always check the label for pesticides before using any animal shampoo, though.