There is a mild and gentle, unscented, pet soap / shampoo made with natural ingredients. This shampoo is so mild it can be used on pregnant and seizure prone pets. It lathers up great, cleanses, conditions, repels and kills fleas upon taking a bath. Since it is unscented, it s good for pets with sensitive skin. Some fragrances in soaps / shampoos, even mild ones, can irritate or aggravate skin, especially sensitive skin. I found this handcrafted, natural, pet soap at: Www.natural-goat-milk-soap.com/pet-care-information.html
I don't think Pugs have a special shampoo, so you can use any dog shampoo, "Dog shampoo" if its older. "Puppy shampoo" if its younger.