What Age Can My Dog Get Spayed/Neutered?

WHAT does spaying or neutering your pet mean?

Spaying a dog means removing a female dog’s reproductive organs.  Generally, when a female dog is spayed, the dog’s ovaries and usually the dog’s uterus are removed.  The surgery is also known as an ovariohysterectomy (when both ovaries and the uterus are removed) or an ovariectomy (when only the two ovaries are removed).  Both procedures are effective and safe.  Spaying a dog eliminates the dog’s heat cycle and the dog will no longer be able to reproduce/have puppies.    

Neutering a dog means removing a male dog’s reproductive organs.  When a male dog is neutered, both testicles are removed.  The surgery is also known as castration.  Neutering a dog eliminates the male dog’s ability to reproduce.  Most of the time, behaviors related to reproduction (like humping or marking) also decrease after neutering.  However, depending on the dog’s age and other environmental factors, this is not always the case.

WHY should you spay or neuter your pet?

Spaying or neutering your dog has numerous health benefits for your pet as well as eliminating unwanted litters.  Spaying female dogs helps prevent mammary cancer and can also prevent pyometra (a possibly fatal uterine infection that usually requires emergency surgery).  Neutering male dogs helps prevent testicular cancer, perianal diseases, and prostatic diseases.  Neutered male dogs are also typically less aggressive, less territorial, and wander less from home.  Additionally, spayed and neutered dogs tend to have a longer life expectancy than intact dogs. 

WHEN should you spay or neuter your pet?

The timing of spaying/neutering in veterinary medicine is a controversial topic.  We will briefly discuss the major pros and cons of early vs late spay/neuter and give you some general guidelines.  However, each individual owner should discuss their pet’s specific circumstances with their pet’s veterinarian. 

On average, female dogs reach sexual maturity and can have their first heat cycle at 6 months of age.  However, this can vary significantly with breed, size, and genetics.  Small breed dogs tend to come into heat earlier with the first heat cycle happening as early as 4 months of age.  Large and giant breed dogs may not come into heat for the first time until they are 12-18 months old. 

If a female dog is spayed prior to her first heat cycle, the risk of mammary cancer is essentially eliminated.  If a dog is spayed after her first heat cycle but before the second heat cycle, her risk of mammary cancer is present but still relatively low.  For dogs spayed after their second heat cycle, 1 in 4 dogs will develop mammary cancer. 

Recent studies have shown certain diseases, like urinary incontinence and some joint diseases (hip dysplasia, cruciate ligament tear), have a higher incidence in dogs that are spayed or neutered early in life.  The new research indicates that sex hormones (estrogen and testosterone) are important for skeletal growth and urethral sphincter maturity.  Interestingly, the size of the dog is an important determining factor for the development of disease.  Small dogs do not have a higher risk of developing urinary incontinence or orthopedic issues regardless of the time of spay/neuter.  Large breed dogs spayed or neutered before they are full grown do have an increased risk of developing urinary incontinence or orthopedic issues. 

With this information, it is apparent that it would be the best practice to spay a female dog AFTER she is done growing and BEFORE her first heat cycle.  The timing of this can be difficult to predict and is sometimes impossible if the dog comes into heat before done growing.  Below are the general guidelines and recommendations of when to get your dog spayed or neutered: 

For small to medium breed dogs, dogs should be spayed at 6 months of age. A small breed dog is a dog who weighs 25 lbs or less when full grown.  A medium sized dog is a dog that weighs 45 lbs or less when full grown.  Small and medium sized dogs do not have increased incidence of urinary incontinence or joint disease regardless of age at time of spaying. 

Large and giant breed dogs should be spayed generally between 9 and 12 months of age. If you have a purebred dog, inquiring with the breeder about the age of onset of your dog’s mother’s first heat cycle can help narrow down the timing.  If your dog has a lineage with urinary incontinence, spaying after the first heat cycle and before the second heat cycle is recommended.  

For small and medium breed dogs, neutering is typically recommended at 6 months. For male dogs, neutering at 6 months helps curb undesirable behaviors like humping, marking, and roaming for females.  If your male dog is a perfect gentleman and behavioral issues are not a problem, you can get your small to medium dog neutered any time between 6 months and 1 year of age. 

Large and giant breed dogs should be neutered between 1 and 2 years of age.

Additional considerations:

Getting your dog spayed at a later age can be more costly as your dog will be larger and require more medications, more anesthesia, etc.  Additionally, the surgical procedure itself is a more difficult procedure the older the dog gets as blood vessels and other structures are fully developed and larger.  Anesthetic risks and risks of internal bleeding tend to be higher the older your dog is. 

Overall, there are many factors to consider when thinking about the perfect time to get your dog spayed or neutered.  Talking to your veterinarian and evaluating your specific pet and circumstances is the best way to make the best decision for your pet. 

For more about the age to get your dog spayed/neutered, contact True Animal Vet at our office in The Woodlands, Texas. Call (281) 867-5968 to book an appointment today.

Dr. Lindsay Nicholson
Director of Medicine
True Animal Vet