When all types of dogs are taken into account, litters have an average of between 6 and 10 small puppies, reports the Tampa Bay Humane Society. Radiography is the best way to assess litter size. This requires that the puppies' skeletons have been mineralized, so that they are visible on an X-ray. This mineralization process begins around 45 days of gestation.
However, this method is not 100 percent accurate, since skeletons may be sitting on top of each other, making it a bit difficult to count. However, this is the best method, since the skulls can be easily counted once prey approaches calving. The size of a puppy litter can be influenced by many different factors, including random circumstances. Therefore, it's almost impossible to predict.
Despite what you've read, you'll never know exactly how many puppies a pregnant female will carry until she's examined by a veterinarian. If the average litter size is six to seven puppies, this means that you could have between 18 and 21 puppies in a year. Another benefit of a late x-ray is to delay the amount of radiation puppies are exposed to when they are extremely underdeveloped. When a dog has its first litter, it will have fewer puppies than when it grows a little and has litters later on.
Even if you keep as planned as possible, in the end, the number of puppies your dog has in his litter depends on Mother Nature. Let's say that for your breed the average litter size is between 8 and 12 puppies, some breeders want to help their mother reach 11, 12 or even 13 puppies. For example, spaniels and retrievers usually have four to eight puppies at a time, while smaller dogs, such as terriers, can only have two, maybe three in a litter. Instead, look at the size of the litter in general, the more puppies there are in the litter, the healthier they will be.
This is because puppies' bones have fully developed at this time, so counting skulls on an x-ray is less likely to be inaccurate. If a dog and her babies together were producing babies, they could have up to 67,000 puppies in a matter of 6 years. After some math, I determined that a female dog would have a 3.2% chance of giving birth to six puppies of the same sex (assuming an equal chance of producing males or females). A traditional way to try to guess how many puppies will be in your dog's litter is to try a sensation for puppies.
Not knowing how many puppies your dog expects can catch you off guard if there are any complications during the birth of puppies. Around day 45 of gestation, puppies will begin to form a suitable bone structure, such as harder bones that have been mineralized to a greater extent. When my first dog was pregnant, I was confused and had no idea how many puppies would be in a litter.