The Shih Tzu's life span is a range of 10 to 16 years. The average is 13 years.
This is an approximation and there are always exceptions. Many Shih Tzu do live until their early teens and some live until their mid teens. The oldest documented Shih Tzu was 23 years old. And the
oldest Shih Tzu currently living
and verified by AllShihTzu is 19 years old (at the time of this writing).
The age of 13 years is considered to be a moderate and average life expectancy in regard to canines. In the United States, dogs in general live to 12.67 years on average, without trauma factored in. When death by trauma is included, it drops to 11.1 years.
Note that overall, female dogs (of all breeds) live 1.5 years longer than males.
Keeping in mind the Shih Tzu's average life expectancy of 13 years, which is very close to the average of 12.5 for dogs in general, let's see how this compared to other pets and animals:
Cats (indoor): 12 to 18 years
Dolphins (bottlenose): 30 to 50 years
Ferrets (kept as pet): 5 to 10 years
Guinea Pigs: 4 to 8 years
Hamsters: 1.5 to 3.5 years
Horses: 25 to 30 years
Parakeets: 10 to 14 years
Rabbits (domesticated, pets): 8 to 12 years
A helpful study conducted by the University of Georgia recorded and summarized the top causes of death of dogs by looking at veterinary records that spanned over two decades. This extensive study documented 82 different purebred breeds, along with mixed breeds. In all, there were 74,556 dogs, including 826 Shih Tzu.
The findings offer a good understanding of the cause of death for this breed. Results are divided into two groups: Puppies, which are dogs under the age of 1-year, and adults which are dogs 1-year and older.
Leading Cause of Death for Puppies
For puppies (dogs under the age of 1-year), cause of death is the same across all breeds. The top 2 reasons are:
#1 Infection.
This includes parvovirus, distemper, and leptospirosis, which can be all but avoided with proper on-time vaccinations.
#2 Trauma.
Death by trauma included fatal injury to the head, body, or both. Some completely avoidable fatal traumas include being stepped on, accidentally falling down staircases, being dropped, and being hit by a car.
3 Top Leading Causes of Death for Adult Shih Tzu
#1 Cancer.
15.1% of Shih Tzu succumbed to cancer. This included a wide variety of cancers including mast cell tumors (a type of skin cancer), lymphoma (cancer of the lymph nodes), mammary gland tumors, bone cancer, and soft tissue sarcomas (includes a group of cancers that involve skin and surrounding tissues).
Note that approximately 50% of all cancers in canines are curable if caught early. Regarding mammary cancer, spraying can significantly reduce the chances of this when it is performed before the age of 2.5 years old.
#2 Urogenital.
13.9% of Shih Tzu died due to urogenital disease. These are issues involving the kidneys, bladder, or prostate. This also includes pyometra (infection of the uterus).
Out of all breeds, the Shih Tzu was among 12 in which death due to urogenital issues occurred most often.
#3 Infection.
7.9% of the Shih Tzu passed due to a fatal infection. This included the diseases as mentioned earlier, seen with puppies, but also fungal infections (such as blastomycosis and histoplasmosis) and protozoal disease (such as babesiosis and leishmaniasis). Additionally, this included bacterial infection, which can develop around a wound, such as bone fractures and breaks (which brings in the issue of trauma).