Leaving a Female Dog Unspayed

Spaying is a common surgical procedure performed on many types of female animals, including canines. The surgery involves the extraction of the female reproductive organs, which are the fallopian tubes, uterus and ovaries. Once a female dog is spayed, she no longer is capable of bearing litters of young.


Unspayed dogs can typically bear two litters annually, with six to 10 offspring per litter. If a female dog lives in proximity to unneutered, unrestrained male dogs, litters of puppies are practically inevitable. The gestational period of canines is 64 to 66 days, according to the University of Missouri Extension.

Heat Cycle

Unspayed dogs go into heat, or estrus, roughly two times each year during their fertile years. When female dogs are in season, it may be apparent to observers, with a variety of key behavioral and physical indications. Some clues of estrus are bloody vaginal emissions, frequent urination, swollen reproductive organs, excessive vocalization, restlessness, anxiety and unusually vigilant behavior. If your pooch is around males of the opposite sex, you may notice her assuming a sexual stance as if to suggest mating activities. This conspicuous position involves raising the rear area and tightening up the hind limbs.

Sexual Maturity

The typical age for sexual maturity differs depending on breed type, and bigger canines tend to be later bloomers than smaller ones. Unspayed dogs usually go into heat anywhere in the range of 6 months to 2 years in age. Once they go into heat, their bodies are fully capable of reproducing. The ASPCA recommends spaying female dogs prior to 6 months of age. Today, altering is often done much sooner than 6 months -- often as early as 12 weeks and sometimes earlier. Consult your veterinarian regarding a suitable time frame for your pet's spaying.


Mammary cancer is relatively widespread in unspayed female dogs, the ASPCA notes. However, this cancer is much less common in pooches spayed before attaining physical maturity. Spayed dogs also have zero chance of experiencing uterine or ovarian cancer. On top of individual medical conditions, leaving female dogs unspayed allows them to breed, contributing to canine overpopulation issues.