The size of a litter can be influenced by several factors, including the breed of the dog, the age of the mother, and her overall health. In general, older mothers tend to have smaller litters than younger mothers, and bitches in their prime (between 2 and 5 years old) tend to have larger litters. Additionally, certain breeds, such as German Shepherds, are known for producing large litters.
It is important to note that the size of a litter does not necessarily reflect the quality of the puppies. Puppies from large litters can be just as healthy and well-behaved as puppies from smaller litters. However, it is important to make sure that the breeder is reputable and that the puppies are being properly cared for and socialized.