Shih Tzu puppies should eat three times daily, and an adult Shih Tzu should eat once per day, according to All Shih Tzu. A puppy needs to eat an ounce of food for every pound it weighs. Adult dogs need to eat half an ounce of food per pound of weight.
While many dogs do fine with having a constant supply of dog food, the Shih Tzu breed is prone to obesity and does better with a monitored diet. Obesity may not be a problem in younger dogs, but it can become a problem in older ones that are less active. Miracle Shih Tzu recommends limiting treats and not overfeeding to prevent obesity.