Spaying holds many benefits for dogs, but at what age should they be spayed? Spaying is possible from just a couple of months old, but the ideal age for spaying depends on who you ask.
So, when can dogs be spayed? According to the ASPCA, at eight weeks old, the average healthy puppy can be spayed. This practice is the same for most rescue organizations and animal shelters.
Rescues and animal shelters spay dogs as soon as possible for three reasons
Firstly, to try to control the pet overpopulation problem that leads to millions of animals being euthanized in shelters each year.
Secondly, to prevent people from breeding newly adopted dogs and adding to the pet overpopulation problem and encouraging backyard breeders.
Thirdly, early spaying and neutering helps to control hormone levels which can lead to behavioral problems like roaming.
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The Traditional Age For Spaying
Traditionally, vets have advocated spaying dogs between the ages of six and nine months.
The average female dog will experience her first heat cycle by six months old, so waiting until right around this time gives a dog a maximum amount of time to grow and develop while still catching most before their first heat cycle.
But if most female dogs experience their first heat by six months, why wait until nine months for some?
Some vets also recommend waiting until nine months old to spay. Waiting like this lets a dog have her first heat cycle, and it gives that dog a little longer for its skeleton to mature and for its body to undergo the natural changes that happen during puberty.
Waiting To Spay Until Skeletal Maturity
Other sources recommend waiting until the skeletal maturity of a dog before spaying. This age is going to vary based on the breed of the dog.
For example, a Corgi will be their adult size when they are ten to eleven months old. A Great Dane, however, does not reach skeletal maturity until twelve to fifteen months old.
Those vets who advocate waiting for skeletal maturity before spaying do so because scientific research has indicated numerous health implications when performing the process earlier.
Spaying At A Year And A Half
Some sources recommend waiting to spay until a dog is around eighteen months old. This recommendation is based on the age of complete maturation in some larger breeds.
Spaying at eighteen months in large breed dogs gives those dogs’ skeletons to completely mature. This is important specifically because of the joint problems associated with early spaying and neutering.
Large breed dogs have a prevalence for joint problems as it is and adding more risk factors too that only increases the chance that a dog will experience painful and malformed joints.
Health And Behavioral Implications Of Spaying Too Early
Some of the published findings relating to health and behavioral problems associated with early spaying and neutering include:
Cornell University College of Veterinary Medicine found that dogs spayed at a young age were much more likely to suffer from hip dysplasia. This is a consequence of being exposed to lower levels of estrogen than dogs spayed later in life.
A 2002 study found that Rottweilers that were spayed and neutered earlier in life had a higher risk of developing bone cancer (osteosarcoma.)
A Texas Tech University study found that dogs spayed and neutered at an earlier age were more likely to experience a CCL rupture than dogs spayed at a later age.
An increased risk of other types of cancers including mast cell tumors, hemangiosarcoma, lymphoma, and transitional cell carcinoma.
An increased prevalence of urinary incontinence (especially in female dogs.)
An increased likelihood of obesity.
Spaying And Neutering In Older Dogs
When we ask “when CAN dogs be spayed?” versus “when should dogs be spayed” it’s also important to look at the older adult and senior dogs. Should they be spayed and neutered too?
This time the answer depends on the individual dog. If you have an older dog and are contemplating spaying or neutering, we recommend talking to your veterinarian directly.
While spaying and neutering older adult and senior dogs still have benefits, those benefits have to be weighed against any risks caused by age. For example, senior dogs with heart conditions often have trouble with anesthesia, so it may be best for them not to undergo spaying or neutering.