Congrats! You’ve made the decision to adopt a new four-legged member into your family. As you undoubtedly want to get started on the right foot, you’ve visited your vet, bought pet health insurance, and plan to have the newest edition spayed or neutered. Perhaps you’ve done a little research on the best time to have this procedure done. The timing of puppy and kitten spaying and neutering is a hotly debated topic with much misinformation and myths, even amongst veterinarians.
Shelters vs. Veterinary Hospitals
Pediatric spaying and neutering is broadly defined as spay/neuter surgery performed between 6 and 16 weeks of age, or any time before the typically recommended 6 months of age. The most common reason this happens at such a young age is due to shelter situations. Shelters are anxious to get puppies and kittens adopted out, and want to help control the pet population by ensuring pets are altered before going to their forever homes. It is unrealistic for shelters to house these pets up to 6 months of age and then alter them.
In a veterinarian setting, this is less of an issue, as your vet hopes to develop a relationship with you and trusts you’ll return for the recommended procedures and the recommended times. The Journal of the American Veterinary Medical Association (JAVMA) has published surgical and anesthetic protocols based on clinical research reporting that early spay/neuter is safe in an effort to stem pet overpopulation.
So we know it is safe, but when is the right time for your pet? Here are some common misconceptions about spaying and neutering pediatric animals.
1. Early spaying or neutering will stunt growth: False
This is likely not clinically true. Some studies even suggest that the growth plates remain open longer when the pet is altered earlier, but this isn’t likely to make any appreciable difference in final size.
2. Early spaying/neutering will protect against certain cancers: True and False
This is true in the case of mammary cancer in females. Literature suggests that the risk of developing mammary cancer in a pet spayed before her first heat cycle is less than 1%, after her first heat cycle her risk rises to 8%. It is false, however, that early neutering protects against prostatic cancer in males. The incidence of prostatic cancer is equivalent in neutered and intact males. 
3. Early spaying causes urinary incontinence in females: Unknown
The jury is out on this one. Cornell university did a long term study on dogs spayed prior to three months and found 12% of the early spayed females versus 5% of the later spayed females developed incontinence, but a Texas A&M research projects suggests there was no change in the numbers affected based on age spayed. There have even been some studies showing the opposite to be true, that females spayed later had more urinary incontinence. Clearly there is a need for more research to settle this dispute.
4. Spaying and neutering causes obesity: False
It is statistically true that altered pets tend to be heavier than their intact counterparts, but obesity is highly linked to a variety of contributing factors and is largely preventable with diet and exercise. Even intact pets can be heavy if overfed.
5. My pet’s personality will change with spaying or neutering: False
There doesn’t appear to be any appreciable effect on personality with early spay/neuter. Certainly a pet spayed or neutered at any age will have fewer hormonally-driven behaviors such as urine marking, territorialism, roaming and fighting.
Be sure to talk with your veterinarian about the timing for your puppy of kitten to be spayed or neutered, and any reservations or questions you have about the procedure.