Dog litter sizes vary from one puppy to more than a dozen newborns. The recorded largest litter had 24. While litter size can impact many aspects of whelping and raising puppies, it does not actually impact the size of the individual puppies. The parents’ genes, the puppy’s breed, and the mother’s health and nutrition determine the puppies’ size at birth.
According to the American Kennel Club, one of the biggest factors in litter size is breed. Small-breed dogs, such as Chihuahuas, do not have room in their bodies for large litters, therefore they tend to produce only two to four puppies per pregnancy. Large-breed dogs, such as Great Danes, usually have larger litters, 10 to 12 puppies being common. Breed type also impacts the size of the newborns. Small-breed puppies are typically several inches smaller than large-breed puppies, regardless of the number of dogs in the litter.
Unusually small puppies are not a result of large litters. Instead, their size can usually be traced back to the health and nutrition of the mother dog before and during her pregnancy. Because the unborn puppies share the nutrition she takes in from her food, she needs an ample diet to properly nourish the puppies. Without sufficient food, the puppies will not reach appropriate size and may suffer health problems. According to veterinarian Kathleen Hefner, writing for the American Kennel Club, most puppies who die soon after birth were probably born from malnourished mothers.
Even though litter size does not impact puppy size, large litters can cause problems for the mother dog and her new babies. If the mother’s uterus attempts to carry more puppies than she can physically handle, her life and the puppies’ lives can be threatened. Also, large litters tend to produce more stillborn puppies and runts. With so many neonatal puppies vying for nutrition, those in the center of the womb often do not get sufficient nourishment, which can cause them to be born small or to die. Great Pyrenees breeder Catherine de la Cruz warns that large litters can trigger earlier-than-expected whelping, which can be a problem for the puppies’ unprepared human grandparents.
While accurately predicting the size of an expectant mom’s litter is difficult, some other factors do contribute. Research shows older mother dogs have smaller litters than younger canine moms. Also, dogs who had their first litter at an older age will have smaller litters. The mother’s weight can be a factor. Obese female dogs tend to have smaller litters than healthy-weight dogs. However, any pregnant mom can experience a large litter relative to normal within her breed. A veterinarian can do an ultrasound to estimate the size of the litter so the household can prepare adequately for the new arrivals.
- American Kennel Club; "Breeder's Handbook: Variables That Influence Litter Size; Bretaigne Jones'
- Litter Size and Singleton; Dr. Carmen L. Battaglia
- White Fire Great Pyrenees; Whelping the Litter; Catherine de la Cruz
- Guinness World Records: Largest Litter - Dog
- VCA Animal Hospitals: Did You Bring Home the Runt of the Litter?
- American Kennel Club; The Care and Feeding of the Breeding Bitch Part One; Kathleen Hefner
- Comstock/Comstock/Getty Images