CATS:
Many feline veterinary organizations recommend that cats be spayed or neutered before they reach 5 months old. NNN recommends 16 weeks. Many cats reach sexual maturity by 5 – 6 months old and can get pregnant or start to spray. For more information, please see www.felinefixbyfive.org.
For feral cats, we recommend spaying and neutering as soon as the cats or kittens can be safely trapped and brought to the clinic! Female cats can be spayed while pregnant or nursing kittens. Kittens can be spayed or neutered as young as 12 weeks of age (3 pounds).
DOGS:
Some research published in the past decade has caused confusion about the best age to spay and neuter dogs. Your veterinarian can discuss these studies in more detail with you if you are having trouble making a decision about when to schedule surgery for your dog.
In general, spaying female dogs before their first heat cycle will prevent unintended pregnancy, eliminate the risk of pyometra (infection of the uterus), and minimize the risk of breast cancer. Neutering male dogs before six months of age will minimize behaviors such as humping and marking, and will eliminate the risk of testicular cancer and minimize the risk of prostate infections.