you'll be fine. When I first got my dogs I could not justify spending 8.00 on 12 oz of "dog" shampoo when I could buy pantene on sale for 1.99 and get 24 oz. of it. Dilute the shampoo (you don't need a gajillion suds) 50/50 with water. The big reason that dogs have a reaction to shampoo is you don't rinse all of the soap away. (which is why dog shampoo is what it is, it doesn't suds as much, and it is more "dilute" than people shampoo). So diluting the shampoo will help and just make sure to rinse rinse rinse. And make sure to keep it away from their eyes. Dog shampoo is really more like baby shampoo (the previous post is correct). And so you don't want the soap in their eyes.

Again, rinse rinse rinse.

I have a dog with skin irritations and he was FINE when I used human shampoo. In fact, I was out of dog shampoo yesterday and so I used Dial's Almond and Milk body wash (for humans) they are all fine, no itching, no redness, nothing.

I am a chemist and I can tell you, the shampoos are going to be nearly identical in terms of content.

And skin is skin. We are all mammals so dog's skin and hair is made up of keratin proteins just like human skin and hair. All people have slightly different pH values to their skin and hair and we all shop in the same aisle for shampoo and soap. Scientifically speaking, you will be fine!