Spay/Neuter of Dogs and Cats

 The Potter League only offers dogs and cats for adoption that have been spayed or neutered (Altered), and advocates, recommends and encourages the Altering of all dogs and cats except those that have overriding issue(s) resulting in veterinary recommendations to the contrary. 

I. What is it? 

Altering refers to the removal of the reproductive organs of female dogs and cats and the removal of the testicles of male dogs and cats. 

II. Why do it? 

There are homeless dogs and cats in every community. In the U.S. alone there are millions entering animal shelters every year. These numbers do not include “street animals” that do not get the opportunity to find a forever home and consequently, through no fault of their own, are faced with a very difficult existence. 

III. Pros 

  • Altering is important for reducing pet overpopulation, as it is the only 100% effective means of birth control. 
  • In general, Altered pets have a longer life span compared to their Unaltered counterparts and veterinary care costs are reduced. Some of the specific benefits to Altering pets include: 
    • Less likely for these animals to roam and thus be exposed to life threatening encounters with cars, other animals and mishaps 
    • Medical evidence indicates a reduced risk of certain types illnesses, including pyometra (potentially fatal uterine infection), uterine cancer, mammary cancer and other cancers of the reproductive system in female dogs, and testicular and non-cancerous prostate disorders in male dogs 
    • Tends to reduce assertive/aggressive behavior, including mounting, fighting, and biting. May reduce, and in some cases eliminate, urine marking in male dogs 
    • Barring other behavior issues in male cats, resolves ~90% of spraying/marking issues and can reduce howling and the urge to roam/fight with other male cats. In many cases, Altered male cats are reported to be calmer and mellower 

IV. Cons 

  • Cost associated with Altering 
  • Some medical studies suggest that Altering: 
    • Increases the risk of osteosarcoma (bone cancer) in some breeds of dogs if performed before one year of age 
    • Increases the risk of cardiac hemangiosarcoma, hypothyroidism, progressive geriatric cognitive impairment, obesity, orthopedic disorders and adverse reactions to vaccinations in dogs 
    • Increases the occurrence of “spay incontinence”, the risk of persistent urinary tract infections and, if done before puberty, the occurrence of recessed vulva, vaginal dermatitis, and vaginitis in female dogs 
  • Altering pets precludes the option of breeding 

V. Conclusions 

Although there is disagreement relative to some of the medical pros and cons on Altering, the behavioral advantages are generally accepted. What we do know for certain is that everyone in the animal community wants what is best for the animals. On the whole the risk to animals lives due to an increase in animal populations is greater than any health risks associated with spay or neuter surgery. In the absence of other ways to prevent animals from repopulating shelters with their offspring, shelters should continue to only offer animals for adoption that have been Altered. 

The cost of Altering can pose a challenging financial burden to some families and can be a significant factor in making this decision. The Potter League recognizes this and has been proactive in promoting and supporting low cost Altering options for all families. The Potter League Spay Neuter Clinic provides a low-cost resource for these procedures. 


  1. Long-Term Health Risks and Benefits Associated with Spay Neuter in Dogs
  2. JVMA News: Study Shines Spotlight on Neutering 
  3. AVMA Collections: Spay/Neuter