Normal variation: It is not uncommon for a dog to have a small litter size, especially if it is their first litter. The average litter size for dogs varies by breed, but most dogs will have between 4 and 6 puppies. However, some dogs may only have 1 or 2 puppies, and this does not necessarily mean that there is anything wrong.
Age of the dog: As dogs get older, their fertility may decline, which can lead to smaller litter sizes. This is especially true for dogs over the age of 7 or 8.
Health problems: Certain health problems can affect a dog's fertility and lead to smaller litter sizes. These health problems may include uterine abnormalities, hormonal imbalances, or infections.
Nutrition: A poor diet can also lead to smaller litter sizes. Dogs that are not getting enough nutrients may not be able to produce as many healthy eggs, which can result in a smaller litter size.
If you are concerned about your dog's litter size, it is always a good idea to talk to your veterinarian. They can help you determine if there is a problem and recommend any necessary treatment.