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Should we spay or neuter our pet, and if so, when?

To spay or not to spay?

This is an important question worth investigating. The best place to start is a conversation with your veterinarian, but the following is a list of factors and scientific facts to consider:

The Background
Dogs and cats are very good at reproducing. They have few predators in the US and are very good at finding food and safe habitats in which to raise their families. In communities where pets are not routinely spayed (female sterilization) or neutered (male sterilization), overpopulation becomes a huge burden on society and the ecosystem. This leads to disease, animal suffering, and the needless euthanasia of millions of animals. Over time, the development of techniques and anesthetics safe for very young animals were developed. When animal shelters began the policy of spaying and neutering every pet, both young and old, euthanasia of homeless animals dropped by millions. This is good news. 

The benefits of sterilizing a pet:

  • Decrease in homeless animals that carry disease and disrupt local wildlife.
  • Prevention of in and outdoor urine spraying/marking by male cats.
  • Prevention of unwanted litters.
  • Decreased territorial aggression.
  • Prevention of pyometra in female dogs and cats (A life-threatening uterine infection that must be treated with emergency surgery.)
  • Prevention of bleeding perianal tumors in older dogs.
  • Decreased rate of mammary tumors in female dogs and cats.
  • Decreased uterine, ovarian, and testicular tumors. 

When is the best time to spay or neuter a pet? 

Many cats have been spayed or neutered before adoption. If not, however, we recommend having the procedure performed after the kitten vaccines are complete; approx 4-6 months of age. "Fix felines by five (months)." 

For dogs, there are several other factors to consider:

  • Large (over 45 pounds expected adult weight ) male dogs (and to a lesser extent female dogs) have an increased rate of ACL tears (cruciate ligament of knee) if sterilized before 1 year of age. This is a severe knee injury that often requires surgical repair. 
  • Female dogs (and less so males) that are spayed before 1 year of age may be more prone to incontinence. (This can often be treated successfully, however,  with oral hormone replacement.)
  • Spaying and neutering at any age reduces metabolic rate a bit, so pets are more likely to gain weight if they are fed the same amount as they were fed prior to surgery.
  • Some female dogs have a recessed vulva (deep fold) if they are spayed before their first heat, leading to an increased frequency of skin fold infections and urinary tract infections. 
  • Some cancers seem to be more common in dogs that are spayed early and some cancers seem less common if the pet is spayed or neutered early, so the jury is still out on this.
  • A good summary may be found here on the AAHA site >>



When to Schedule Surgery


4-6 months of age

Small Dog (adult weight less than 45 lbs.)

6 months of age (before the first heat cycle)

Dog (adult weight more than 45 lbs.)

12-15 months of age (at skeletal maturity)

Important factors (or exceptions) to discuss with your veterinarian before scheduling surgery

  • Behavior Concerns

  • Group activities such as camp or dog parks

  • Urinary issues (infection, incontinence, or vulvar conformation concerns)

  • Plans for breeding your pet

  • Certain cancers


Should we spay or neuter our pet Countryside Veterinary Hospital