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August 1, 2010

Why Spay/Neuter is Important

Humane Society International

  • Puppies may be cute, but too many is a tragedy. Paul Cotney/istockphoto

The implementation of sustainable spay and neuter programs is the most effective method of addressing canine and feline populations that have exceeded the capacity of the local community to properly care for them.

Reasons to spay/neuter animals

Spay/neuter benefits animals for a number of reasons. Among them:

Spay/neuter slows population growth

Without spay and neuter initiatives, homeless animals are often euthanized, neglected or die of disease. Sterilization is critical for management of overpopulation and related disease control concerns.

On the subject of an effective approach to rabies vector control, the World Health Organization (WHO) states:

“There is no evidence that removal of dogs has ever had a significant impact on dog population densities or the spread of rabies. [...] Three practical methods of dog population management are recognized: movement restriction, habitat control and reproduction control."¹

Spay/neuter curbs undesirable hormone-related behaviors

Females no longer have a heat cycle; this eliminates the attraction and approach of unwanted attention by male dogs.

Roaming is greatly reduced; male dogs, especially those used for security, are less likely to wander off an owner’s property if they do not have the hormone drive to pursue a female in heat. This way, they can better serve as watchdogs, might not be tied up, and are less likely to contract disease or suffer injury. Castrated dogs may actually be more protective, as they no longer are distracted by the temptations of breeding or fighting with other males.

Spraying and marking in males is reduced.

Behavioral anxiety and aggression is decreased; this in turn helps decrease the occurrence of dog bites.

Spay/neuter reduces health risks for the animals themselves

There are a number of potentially fatal health conditions and transmissible diseases that animals can contract or develop as a result of being intact and breeding; for example, pyometra, TVT, reproduction cancers. These risks are eliminated when the animal is spayed or neutered.

On the whole, animals who have been sterilized at an early age tend to live longer, healthier lives, potentially increasing their lifespans by an average of one to three years for dogs, and three to five years for cats.


Myth: An animal needs to have a litter/one heat before sterilization.

Fact: Waiting for this to occur actually increases medical risks for the animal.

Myth: Spay/neuter is unnatural or upsetting to the animal.

Fact: The domestication of animals removed them from the "natural order" and placed responsibility for their care with humans. Applying human emotions to animals is neither realistic nor applicable when it comes to identifying a need for sterilization.

More facts

Euthanasia rates increase exponentially in areas where there are no viable spay/neuter programs readily available.

Dogs are 15 times, and cats are 45 times, as prolific as humans.

Dogs and cats enjoy many behavioral and health benefits from surgical sterilization.

Read more myths and facts about spay/neuter

Making change 

When evaluating the risks that result from domestic animal overpopulation, including public health concerns, animal health risks and behavioral concerns, spaying and neutering clearly becomes the undeniably responsible option.

Working together, we can solve this problem. Participate annually in World Spay Day and find resources near you.

¹WHO Expert Committee on Rabies: Eight Report (WHO Technical Reports Series: 824), 1992, ISBN 9242208248, ISSN 0373-3998, NLM: WC 550, form # 9.4 Dog population management.