We've avoided shampoo in the first 8 months of puppy's life and if he gets a bit stinky we'd use dry shampoo and when he's muddy we'd just rinse him off with water, but recently since we transitioned to wet food he has got some stuck in his beard and so it's beginning to smell and water won't rinse it out . Any suggestions as to what shampoos are safe and healthiest for his coat, usa based?