A Shih Tzu (UK: /ˌʃiːˈtsuː/, US: /ˈʃiːˌtsuː/; Chinese: 西施犬; pinyin: Xī Shī quǎn literally 'Xi Shi dog', also spelled Shittsu) is a toy dog breed, weighing from 4 to 7.25 kilograms (9–16 lb) when fully grown. The breed was developed in China. 6 Health. The Shih Tzu may be more prone than other breeds to get a blood disease called immune-mediated hemolytic anemia, which causes their immune system to attack itself and kill off their blood cells. This can be found through blood tests but among the signs are yellowing of the skin/gums, tiredness, loss of appetite, and loss of balance that occurs over two days. Shih Tzu puppy. A number of health issues, some of them hereditary, have been found in individual Shih Tzu, and are listed below.