The main problem with medicated shampoos is that they were invented for horses and later marketed for dogs. They are industrial strength detergents and they dry out already damaged skin.
The second problem is that they are almost always prescribed for the wrong thing. Most of them are anti-bacterials which are fine at killing germs but really hard on itchy, inflamed skin. Dogs that lick their paws aren't usually suffering from a bacterial or fungal infection. If they are, it's a secondary problem and there are better ways to handle it. The primary issue is inflammation caused by histamine, as a result of allergies. The objective is to make it itch less so the dog stops licking his skin off and causing all the other resulting problems (infections, sores, scabs, bleeding, hair loss, etc.).
The second category of medicated shampoos are the ones prescribed for seborrheic dermatitis. These shampoos are in the T-Gel, Selsun Blue family. They are not gentle shampoos. They are designed to dissolve oils and fat deposits on the scalp. They are especially harsh on dogs whose skin is already dry and itchy. Very few dogs ever get dandruff. The ones that do don't lick their paws as a result. These shampoos will make things more itchy, not less.
Only a few medicated shampoos are actually designed for allergic skin inflammation. One variety contains hydrocortisone. It works pretty well for serious skin itching. It's also relatively safe for your dog because all the hydrocortisone goes down the drain and your dog can't ingest it. But it doesn't last more than a few days and the baths require 20 minutes of soaking. It's a good backup plan for bad flareups but isn't really a good management tool. It's more of a bad case scenario.
The theory behind the other variety of shampoo for allergic dogs is that it creates a surface that is too slick for bacteria to adhere. That sounds pretty good, but bacteria aren't the problem. It's inflammation and itching. Unfortunately, this shampoo is excellent at removing every last molecule of oil and moisture, leaving skin more dry and itchy than before.
If you are currently using a medicated shampoo, you can give it a test by lathering up both your arms past your elbows, then rinsing and drying. If your skin feels great, we stand corrected. If your skin feels dry, or uncomfortable, or itchy, it’s probably making your dog's skin feel the same way.
The best shampoo is no shampoo. If you want to help your dog feel better, give him a bath in some luke warm water with a few tablespoons of baking soda dissolved in it. The baking soda will absorb pollen and raise the pH level of his skin. It can often relieve itching for a few hours and calm down irritated skin.
Most shampoos for people are too acidic for a dog. Acidic shampoo lathers up great and makes your hair shine. But a dog has more alkaline skin than a person, and sometimes shampoo that makes hair look good isn't that great on their skin.
The best choice is shampoo with aloe vera, oatmeal, and coconut cleansers. Don't use anything that's medicated or has any special ingredients or perfumes. It may not make your dog's hair quite as silky smooth, but his skin will be in a lot better shape.
Try to bathe your dog as little as possible. Even the mildest shampoo can wash away natural skin oils. We just mean keep it under once a week for little dogs and once a month for big ones.
If they are really stinky, that's a different story. If there's no visible infection, they may be eating stinky foods. Some game meats and alternative proteins can be pretty stinky, especially fish. If you currently give your dog fish oil capsules, you might want to reconsider. We've never heard of any dog ever having a significant benefit from fish oil, but we've heard of quite a few who have fishy breath, fishy burps, or fishy body odor. A significant number of dogs are also allergic to fish or fish oil. The idea behind giving your dog fish or fish oil is sound, but in practice it never seems to help and can often have unintended results.