If Fido or Fluffy is part of your family, the topic of spay or neuter has probably come up.  To many pet parents, these procedures are as routine as puppy or kitten vaccines.  Surprisingly, though, pet owners are often unaware of what spaying or neutering entails, and the special considerations for their own little Fido or Fluffy.

Spay and neuter are surgical procedures in pets to remove the reproductive organs.  In females, the ovaries and uterus are removed.  This is called a spay, and it is comparable to complete ovariohysterectomy in women.  In males, the testicles are removed.  This differs from vasectomy in men, which is a birth control procedure that leaves the testicles intact.

As with any surgery, spaying and neutering procedures are multifaceted.  Only best practices should be acceptable to ensure safe general anesthesia, O.R. cleanliness, surgical technique, and pain management.  Since shortcuts increase patient risk and discomfort, be sure to discuss these issues with your veterinary team so that your Fido or Fluffy receives only the best care.  Fortunately, the American Animal Hospital Association inspects hospitals and accredits those with a proven track record of excellence, including in areas of anesthesia, surgery, and pain control.  These hospitals would have the red “AAHA-accredited” logo proudly displayed in their front lobby.

Traditionally, pets were spayed or neutered by six months of age.  Performing these surgeries in young cats and dogs eliminated unplanned pregnancies and litters, unwanted heat periods, and undesirable sexual behavior.  That’s because sexual maturity, or puberty, doesn’t affect cats and dogs until six months of age or older.

However, if the decision whether and when to spay or neuter your Fido or Fluffy is left to you, here is some information to consider.

Unless you are a breeder, or you intend to show your pet, spaying and neutering is probably a good idea.  Responsible pet ownership includes being proactive to prevent unwanted litters.  In addition, spaying prevents pyometra, a life-threatening infection of the uterus.  Neutered dogs develop fewer diseases of the prostate, and generally wander less and are less aggressive.

For most pet owners, the question is not whether to spay or neuter their pet, but when is the best time to do it?  The answer to that question is: it depends on several factors.

If your pet is a cat, aim to spay or neuter at five to six months of age.  Cats are precocious animals and reach puberty by six months.  Unspayed females go into heat and will get pregnant.  Although Mr. Fluffy doesn’t go into heat, if he is not neutered, his urine odor suddenly changes when he hits puberty.  He’ll announce his active hormones by spraying pungent urine on walls, laundry, bedding, or furniture.

Although dogs may also reach puberty at six months of age, there are other factors to consider for Fido.  Of particular significance are gender, and breed.

Female dogs that are spayed have a lower risk of developing breast cancer later in life.  In fact, every heat period for the first few years increases this risk.  Regardless of your dog’s breed, spaying her before her first heat will essentially eliminate her risk of developing mammary cancer later.

Other cancer risks may increase or decrease, depending on age of spay or neuter, and breed.  Interestingly, these risks vary by breed.  For example, spaying and neutering decreases the risk of some cancers, but increases the risk of others.  This pattern is different in golden retrievers compared to Labrador retrievers.  Be careful not to extrapolate from one study and assume that the same risks hold true for another breed.

Another consideration is how big Fido will be at maturity.  Spaying or neutering larger dogs while they are still growing may risk joint or orthopedic problems later.  Sex hormones influence long bone growth.  Spaying or neutering removes the sex hormones and alters what nature intended for growth.  Doing this before these bones are finished growing can affect joint physics and predispose Fido to injuries later.  For larger male dogs, waiting until their bones are finished growing is generally a good idea.  For female dogs, the orthopedic benefit of waiting for maturity should be weighed against the risk of mammary cancer.

Spayed and neutered pets tend to be more overweight.  With pet obesity on the rise, be sure to watch Fido’s and Fluffy’s calorie intake, especially after the spay or neuter surgery.

Some spayed dogs also develop urinary incontinence later in life.  These cases often respond favorably to medication, including hormone therapy.

For pets, the advantages of spaying or neutering often outweigh the disadvantages.  Discuss pros and cons with your veterinary team, so that you can make the best decision for your Fido or Fluffy.