I’m agreeing with Amy. Maybe try an elimination diet…if you’re switching Kibbles, try to make a list of identical and different ingredients and which kibble he did good or bad on.
There’s that possibility of environmental allergies as well. I think you can get allergy pills for dogs, so you might try that if you’re pretty sure it’s not food related. Try giving raw local honey daily, too. I know many people who swear by it for theirs and their dogs’ allergies.
Only way to see if the shampoo does it is by ditching it and seeing if that makes any difference. My lab is occasionally itchy, so I use a medicated shampoo (I can’t remember the name of mine, but Malaseb is very similar I think).
You also might try another shampoo: Shea Moisture African Black Soap shampoo. It’s not designed for dogs, but it is an organic shampoo that has ingredients to help dandruff and itching. I use it myself and we loooooove it. (You can prob find it online, but it’s usually at Walmart, Target, and Walgreens for about 10$)
Shampoos usually won’t fix a problem though, just mask it. Get a skin scraping done to make sure it isn’t something like mange. Best wishes and hopefully you can get through this!
