* Age of the mother: Younger dogs tend to have larger litters than older dogs.
* Genetics: Some Shih Tzus are genetically predisposed to having larger or smaller litters.
* Overall health: A healthy Shih Tzu is more likely to have a larger litter than one with health issues.
* Environmental factors: Stress, nutrition, and other environmental factors can also influence litter size.
Generally, Shih Tzu litters range from 1 to 5 puppies, with an average of 3-4 puppies.
It's important to note that a responsible breeder prioritizes the health and well-being of the mother dog and puppies. They will ensure the mother is properly cared for during pregnancy and will not intentionally breed for the largest possible litter.