Can you add wheat dextrin to your dogs diet?

Yes, although I don't know why you would want to. Commercial dog food is very carefully blended to have the right balance of nutrients and all the reputable brands have a great deal of scientific research behind their formulae. Adding a supplement like wheat dextrin could throw off the balance of nutrients. Also, some dogs are allergic to wheat products, so adding wheat dextrin could cause an allergic skin reaction.

However, if you are advised by your veterinarian to add wheat dextrin, I would follow your vet's advise as he will know more about your dog's particular medical status and have a reason for adding the supplement.