Is there a good “age” to spay a female puppy? In my case a Keeshond, so a medium sized dog.
When I was in veterinary school it was an article of faith that dogs should be spayed before their first heat. Several reasons were offered: dogs spayed after their second heat develop breast cancer at 30 times the rate of those spayed before the first heat. Dogs spayed before the first heat cannot get pregnant or suffer from any of the myriad complications that pregnancy may entail. Younger dogs’ uteruses have smaller blood vessels, so the risk of hemorrhage during surgery is low. Young dogs tolerate anesthesia better than older dogs. Young dogs are less likely to be obese (this means that the surgery will be simpler and require less time under anesthesia).
All of the above statements were and are true. But recently some slight evidence has come out to suggest that there may be some mild downsides to early spays. Dogs who are spayed early may be more likely to suffer from obesity later in life. Spaying later may reduce lifetime risk of knee injury. And in one study with a very small sample, extreme longevity was linked to leaving dogs intact.
On balance I believe that spaying before the first heat is in most dogs’ best interest. I generally recommend spaying at 4 – 6 months. But remember that few things in life are simple or completely cut-and-dried — especially something as intricate as spaying a dog.