Great Pyrenees typically give birth to litters of between six and 12 puppies. For a breed like the Great Pyrenees that can grow larger than 100 pounds, this range is typical.
A 2011 study published in Theriogenology found that the variable that had the largest influence on litter size was the size of a breed; larger dogs produce larger litters. Miniature breeds had litters containing a mean of 3.5 puppies, while the mean litter size of giant breeds was 7.1. In addition to size, the age of the dog giving birth has a secondary influence. Generally, dogs aged 3 to 4 years produce the largest litters. Artificial insemination also tends to produce smaller litters than traditional mating methods.