6 Month Old Tibetan Terrier won't stop biting & scratching himself!?

Check for fleas and have him checked for parasites. It could be a food allergy. Nutro and Science Diet are both full of the most common allergens. The most common allergens are corn, wheat, soy, yeast, chicken, beef, eggs and dairy products. Which Blue Buffalo formula are you using? Blue Buffalo has no corn, wheat or soy in any of their products. Their Lamb and Brown Rice formula has none of the common allergens. If that is not the one you are using, switch. It is high in Omega 3 fish oil also.