Three Islands Veterinary Services

115 East Street North (PO Box 639)
Bobcaygeon, ON K0M 1A0


At what age can I have my pet spayed or neutered?
What is the best age to spay or neuter my dog?

For many years veterinarians have traditionally answer this question as 6-7 months of age, before your pet hits puberty. However, some new studies are suggesting that there may be benefits to waiting until after a dog is physically mature, usually after 12 months of age (18 months in the giant breeds). 

What are the BENEFITS to spaying and neutering after 12 months of age?
Although recent studies on Labrador's, Golden retrievers and German shepherds are not perfect, they do suggest that there is a very significant reduction in the risk of getting certain joint problems (hip dysplasia, ACL knee injuries and elbow dysplasia) if we spay and neuter these dogs after 12 months of age.  Also, male dogs who go through puberty may have a more "male" look to their head and chest.  Some people consider this appearance more desirable. 

What about cancer?
Some breeds may have a reduced risk of some types of cancer if spayed or neutered later in life.  Not a lot of studies have been done on this. (The exception is female breast cancer where the risk INCREASES when pets are spayed later in life). 

What are the DISADVANTAGES of spaying and neutering after 12 months of age?
Dogs will go through puberty before 12 months of age. 
Females will usually have had at least one heat cycle by then during which they will have 2-3 weeks of messy bleeding and attract male dogs and risk unwanted pregnancy.
Females also risk uterine infection and may develop undesirable hormonal behavioral changes.

Male dogs who hit puberty are often more difficult to manage. They may roam looking for females and staking territory, have undesirable urine marking, 'mount and hump' inappropriately and have increased risk of aggressive behavior.  They can be harder to train due to their hormonal distractions. 

What about other breeds? When do we spay and neuter them?
Unfortunately, we have more questions than answers. Most breeds do not have studies done on them. We do not know if the same findings that apply to labradors also apply to boxers or poodles.  Some breeds naturally have a very low risk of joint problems so will have much less benefit to a later spay or neuter

So what are the current recommendations?
At Three Islands Veterinary Services, we feel that each pet should be evaluated individually looking at breed risks and owner experience and owner desires.  We should talk about the pros and cons before booking a surgery, usually at one of the puppy vaccination/checkup appointments.   

It is certain that future studies and new information will change our recommendations but at this time these are our general guidelines:

- Animals in shelters: Consider unwanted pregnancies. Spay/neuter before adoption 

- Large and giant breed dogs with a known risk of ACL knee injury: Consider waiting to neuter/spay until full growth is achieved. 

- Breeds with high risk of osteosarcoma bone cancer or hemangiosarcoma cancer: Consider waiting to neuter spay after one year 

- Dogs with lots of mammary cancer in their line: Spay at 6-7 months of age 

- Does the dog owner have experience handling intact animals? If not, consider neuter/spay at 6-7 months of age before puberty

- Is there exposure to other dogs in the household or at doggie daycare or puppy training classes or boarding kennels where hormonal behavior problems may become an issue? If so consider neuter/spay at 6-7 months of age before puberty. 

- Remember that by spaying before the first heat cycle will reduce a female dog's chance of mammary cancer significantly.

There are many factors to consider and we would be happy to discuss them with you.