Female dogs experience a “heat” cycle approximately every six months, depending upon the breed. A female dog’s heat cycle can last as long as 21 days, during which your dog may leave blood stains in the house and may become anxious, short-tempered and actively seek a mate. A female dog in heat may be more likely to fight with other female dogs, including other females in the same household.
Female cats can come into heat every two weeks during the breeding season until they become pregnant. During this time they may engage in behaviors such as frequent yowling and urination in unacceptable places.
Spaying eliminates heat cycles and generally reduces the unwanted behaviors that may lead to owner frustration and, ultimately, a decision to relinquish the pet to a shelter. Most importantly, early spaying of female dogs and cats can help protect them from some serious health problems later in life such as uterine infections and breast cancer.