Canadian Veterinary Medical Association

Neutering of Dogs and Cats (spay and castration) – Position Statement

July 30, 2012


The CVMA believes that neutering is an important aspect of responsible pet care both because it helps to combat dog and cat overpopulation, and because of the health and behavioural benefits to the animals. The CVMA strongly recommends that all cats and dogs which are not part of a responsible breeding program be neutered before sexual maturity, except where there are valid health or behavioural benefits for delaying the procedure.


  1. The CVMA advocates for prepubertal neutering of pet cats and dogs, except where there are valid reasons to delay the procedure. As with any veterinary procedure, the decision to neuter should be made by the pet owner based on discussion with the veterinarian.
  2. The CVMA suggests that in most cases, male and female cats be neutered prior to 5 months of age.
  3. Research shows a significant reduction in mammary gland tumours in female dogs and cats neutered prior to sexual maturity (1,2). The benefits of early neutering of male cats include preventing the birth of more kittens that may contribute to the cat overpopulation crisis, as well as reduced aggression and marking behaviour (3).
  4. For male dogs, in addition to preventing unwanted pregnancies, neutering reduces inter-male aggression. There are studies suggesting a negative impact on bone growth from early spaying and neutering, particularly in large breed animals (4,5). More research is required to explore this issue.
  5. The CVMA strongly supports early (6-16 weeks) neutering of cats and dogs at animal shelters. This ensures that all animals are neutered before adoption and do not contribute to ongoing animal overpopulation issues.
  6. Ovariectomy alone is commonly performed on companion animals in parts of Europe. Potential advantages include minimizing surgical invasiveness and increasing surgical speed and time to recovery (6,7). Further research is needed to determine whether this is a preferred alternative to routine ovariohysterectomy.
  7. The CVMA supports all educational efforts to promote responsible pet ownership, including that neutering companion animals is part of being a responsible owner.
  8. The CVMA also strongly supports research into safe nonsurgical methods of sterilization.


  1. Root Kustritz MV. Determining the optimal age for gonadectomy of dogs and cats. J Am Vet Med Assoc 2007;231:1665-1675.
  2. Bushby PA, Griffin B. Veterinary Medicine: An overview of pediatric spay and neuter benefits and techniques. February 2011.
  3. Howe LM, Slater MR, Boothe HW, et al. Long-term outcome of gonadectomy performed at an early age or traditional age in cats. J Am Vet Med Assoc 2000;217:1661-1665.
  4. Zink C. Early Spay-Neuter Considerations for the Canine Athlete. [page on Internet] Available from: Last accessed Sept 5, 2012.
  5. Howe LM. Rebuttal to “Early Spay-Neuter Considerations for the Canine Athlete” [page on Internet] Available from: Last accessed Sept 5, 2012.
  6. Van Goethem B, Schaefers-Okkens A, Kirpensteijn J. Making a rational choice between ovariectomy and ovariohysterectomy in the dog: A discussion of the benefits of either technique. Vet Surg 2006;35:136-143.
  7. Coe RJ, Grint NJ, Tivers MS, Hotston Moore A, Holt PE. Comparison of flank and midline approaches to the ovariohysterectomy of cats. Vet Rec 2006; 159:309-313.

(Adopted July 2012)