What’s the Right Age to Spay or Neuter a Dog?

March 5, 2020
The benefits of spaying or neutering a dog have become better known in recent decades to the point that they've become routine. In fact, if you adopt a dog from a shelter, it's quite probable that they've already had this procedure.

Many pet owners may wonder about the right age to get their pet neutered or spayed, but recent studies have revealed that choosing the right age to spay or neuter a dog may not be that straight forward.

The benefits of neutering or spaying a dog

Firstly, neutering and spaying are strongly linked to greater life expectancy. Life expectancy increases by 26% for females and 18% for males when compared with dogs that haven’t been spayed or neutered.

This happens because the procedure significantly reduces the risk of death from a number of diseases, including some types of cancer, trauma, and infections.

Although there are associated risks, such as other types of cancer and orthopedic problems, the benefits outweigh the potential problems.

Three young puppies who may be the right age to spay or neuter a dog.

When is the right time to neuter or spay a dog?

Often, the procedure is performed at a very young age, even as young as two or three months old. This mainly happens in animal rescue shelters and is done to control the canine population.

This is seen as an important step for animal rescue organizations because only 40% of pet owners comply with their neutering or spaying commitments. As a result, it’s seen as a sensible move to spay or neuter a dog prior to adoption.

Ultimately, this practice aims to help public health and prevent animal suffering as a result of overpopulation. Questions still remain about the safety and long-term effects of carrying out the procedure at such a young age, despite there being considerable literature on the topic, some of which is contradictory.

Is there a right age to spay or neuter a dog?

New information about the benefits and risks of carrying out the procedure in later life is coming to light all the time, and, doubtlessly in the future, current recommendations will continue to be reviewed and reassessed.

  • Small breeds – dogs that weigh less than 22 kg in adulthood: the recommended age is six months old in males, and in females, before their first heat – about 5 or 6 months old.
A large dog next to a small dog.

  • Large breeds – dogs that weigh more than 22 kg in adulthood: recommendations are less strict.

If males are neutered when they’re older, the risk of some types of cancer and orthopedic problems is reduced. However, there are some behavioral problems that may need to be addressed.

For females, spaying in adulthood can reduce the risk of some types of cancer but increase the risk of others. Like males, it can also reduce the risk of some orthopedic problems.

Large dogs

A recent study on the link between the age of neutering/spaying and performance was carried out on 450 trained service dogs. The results determined the following optimal ages for neutering or spaying:

Age of neutering/spaying
Dog in a shelter Before adoption (from 6 weeks old)
Small breed, male or female Before 5 months old
Large breed, female Before 5 months old
Large breed, male – freely roaming Before 5 months old
Large breed, male – house pet Between 7 and 11 months old. Ideally, after closing the growth plates: 15-18 months

In summary, we can see, taking the pros and cons into consideration, that the recommended age is to spay or neuter a dog between 5 and 6 months old for most dogs.

As with all things, there are exceptions, and it’s always a good idea to discuss any concerns you have with your vet. They’ll help you make the right decision, both for you and your pet.

  • Zlotnick, M., Corrigan, V. K., Griffin, E., Alayon, M., & Hungerford, L. (2019). Incidence of Health and Behavior Problems in Service Dog Candidates Neutered at Various Ages. Frontiers in veterinary science, 6, 334.
  • Bushby, P. A. (2018). The Optimal Age for Spay/Neuter: A Critical Analysis of Spay Neuter Literature. In Southwest Veterinary Symposium.