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Why and When to Spay or Neuter
Your Pet

Below is a PDF document on the optimal age for spay/neuter - both the pros and the cons.


To summarize, this is what we do know....​


CATS Should be sterilized by 5 months of age. "Feline Fix by Five"

In 2016 the Veterinary Task Force on Feline Sterilization was convened to look specifically at spay neuter issues in cats. What they found was that having cats spayed before their first heat cycle:

  • Significantly decreases the risk for mammary carcinoma, which in cats is 96% malignant, and most do not survive one year.

  • Eliminates reproductive emergencies such as pyometra (a life-threatening uterine infection) and dystocia (difficulty birthing)

  • Prevents unintended pregnancies that may occur as early as 4 months of age

  • Potentially decreases behavioral problems linked with cat relinquishment.

DOGS - For owned dogs, the owner must make an informed decision based on species, breed, intended usage and current medical knowledge at hand.  For most breeds the protective effect of spay before the first heat cycle on mammary cancer far outweighs the potential risks associated with other cancers and orthopedic conditions.

  • Owned female dogs spay prior to 5 months of age.

  • Owned large breed male dogs - house pets– orthopedic concerns may outweigh all others – spay/neuter after growth stops 15 –             18 months. Keep in mind that some dogs will develop behavioral issues by this age, that may not be corrected by neutering.

  • Owned large breed male dogs - free roaming– population concerns may outweigh all others – spay/neuter prior to 5 months of age.

  • Owned small breed male dogs – no evidence at this time for orthopedic issues – castrate prior to sexual maturity – 5 months.


The chances of a sterilized dog getting certain cancers, some immune conditions and certain orthopedic conditions, is 3.0% versus the chances of an intact female dog getting mammary cancer at 20% or pyometra (a life-threatening uterine infection) at 24%.​​​​

Click below for Optimal Age Spay / Neuter Handout

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