The older the prey, the smaller the litter, especially in larger breeds. Mothers raised 2 to 5 years old tend to have the largest litters. Despite the age of the prey, the first 2 litters will generally be smaller than the later ones. A typical Golden Retriever litter can have four to 12 puppies.
Usually, the first litter of a female Golden Retriever is smaller than the later litters. First-time pregnancies tend to produce fewer puppies. The breed of dogs selected for mating and, therefore, breeding surely has an impact on the number of puppies produced. Smaller breeds usually give birth to smaller litters compared to larger breeds.
Usually, the size of a dog litter is mainly based on the size of the dog's body simply because biologically, larger bodies are capable of carrying a larger litter than smaller bodies. Towards the end of your dog's pregnancy, the vet will likely be able to feel the mother's belly or take an X-ray to determine an “exact number of puppies in their belly” (although it can be easy to miss one of the puppies, so you'll never know for sure until the little wiggles start to come out). For example, dogs of breeds that normally produce litters of five puppies can only produce one or two for their first litter. The average number of puppies in a litter of German Shorthaired Pointer ranges from 8 to 12 puppies, but smaller and larger litters are expected.
But understand that this is a statistical correlation, not a way to predict the number of puppies your individual dog will have. There is also a small time interval, between day 28 and 35 of pregnancy, in which the veterinarian can feel your dog's abdomen safely. According to the Association of American Feed Control Officials (AAFCO), the minimum level of crude protein on a dry matter basis for a pregnant dog's diet is 22 percent. Dogs under the age of seven generally have smaller litters than older dogs, but they should never be raised too early or too old.
But just as each dog breed differs in size, function and personality, they also differ when it comes to litter size, according to AKC registration data. The dogs that produce the largest litters are middle-aged dogs, while very young and old dogs tend to produce smaller litters. In the old days, the practice consisted of counting the number of nipples the dog had to obtain an average number of puppies to expect in a litter (the so-called half-nipple rule), but this practice proved to be inaccurate for many reasons. That's why Shih Tzu, Pomeranians and Chihuahuas have litters that usually range from one to four puppies, while Cane Corsos, Great Danes and other giant breeds usually give birth to eight or more puppies.
Larger litters will most likely occur when the male dog is less than 5 years old, since it is easier for sperm to enter the female's eggs and most sperm are of higher quality. You can't put two parents who previously produced large litters and expect puppies to produce large litters two years later as well. We have a mastiff pitbull mix that got pregnant with a Newfoundland and had 16 puppies this time 12 that survived and the last time had 15 puppies all survived the same mother same father both times fathers as mothers of 3 years like four or five.