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Neutering of Dogs and Cats - Position Statement
August 13, 2019
The Canadian Veterinary Medical Association (CVMA) strongly recommends that cats and dogs not intended for breeding be neutered before sexual maturity, except when there are scientifically justifiable health or behavioural benefits that might be gained by delaying the procedure.
- The CVMA supports all educational efforts to promote responsible pet ownership. Prevention of unplanned breeding (permanently accomplished by neutering companion animals) is an integral part of being a responsible owner.
- Neutering dogs and cats can also provide health and behavioural benefits, such as reduced risk of some diseases and undesirable behaviours that are influenced by reproductive hormones.
- An owner’s decision to neuter, including when to neuter their pet, should be made in consultation with a licensed veterinarian after an assessment of each patient.
- The CVMA advocates for pre-pubertal neutering of cats.
- The CVMA advocates for pre-pubertal neutering of dogs, except when there are valid evidence-based reasons to delay the procedure.
- The CVMA advocates for further research into preliminary data that may suggest large and giant breed dogs benefit from neutering after growth plate closure.
- The CVMA supports neutering of dogs and cats prior to adoption from animal shelters.
- Neutering is defined in this document as the surgical removal of gonads (testicles or ovaries, which might also include removal of the uterus) in both male and female dogs and cats. It is a method of contraception and has the added benefit of aiding in the prevention of diseases of the reproductive system (1).
- The CVMA holds that surgical neutering of dogs and cats is a veterinary procedure. As such, all neutering procedures must adhere to sound veterinary surgical and aseptic technique with adequate pain control to minimize complications (2).
- The CVMA supports all educational efforts to promote responsible pet ownership. Prevention of unplanned breeding is essential to controlling pet overpopulation, and is an important part of being a responsible owner.
- Neutering prior to sexual maturity reduces the incidence of reproductive hormone dependent diseases, reduces surgical complication rates, and shortens recovery and healing times (3,4). Research shows a significant reduction in mammary gland tumours in female dogs and cats neutered prior to sexual maturity (3-5). Pyometra and other uterine or ovarian diseases are also prevented with the removal of these organs in female dogs and cats.
- The benefits of pre-pubertal neutering of male cats include preventing the birth of more kittens that contribute to the cat overpopulation crisis, as well as reduced urine marking, and some forms of aggressive behaviour (5,6). Reproductive hormone influenced behaviours of male cats, such as urine spraying, makes them undesirable as household pets, and is a common reason for relinquishment to shelters (3).
- For male dogs, in addition to preventing unwanted pregnancies, neutering reduces certain undesirable behaviours such as status-related aggression, urine marking, mounting, and roaming (3,7). Neutering male dogs can also prevent most types of prostate disease (e.g., hyperplasia and prostatitis), with the exception of prostate cancers and paraprostatic cysts (8).
- There are some studies suggesting a negative impact from pre-pubertal neutering in large breed dogs. These studies implicate certain bone developmental abnormalities, urinary sphincter incontinence, cancers and undesirable behaviours, in some neutered large and giant dog breeds, particularly when neutered before full maturity (9-12). More research is required to explore these issues, as current data are conflicting, few breeds have been investigated, small sample sizes are studied, and most are retrospective studies. Longitudinal and case control studies are lacking.
- The CVMA strongly supports neutering of all cats and dogs at animal shelters prior to adoption to prevent ongoing contributions to pet overpopulation issues. Low compliance rates have been reported for post-adoption spay and neuter shelter programs (4). The rate of owner relinquishment increases for sexually intact dogs and cats (4,13).
- Vasectomy and tubal ligation result in contraception, but do not remove the gonads. These are surgical procedures with no additional benefit to the animal to prevent reproductive hormone dependent diseases, as hormones are still produced. These techniques also do not have the added benefit of preventing undesirable reproductive hormone dependent behaviours (e.g., status-related aggression, urine marking, mounting, and roaming). Thus, these surgeries are not commonly performed by veterinarians, nor recommended by the CVMA.
- The CVMA supports research into safe and efficacious nonsurgical methods of sterilization. However, preliminary research into immunocontraception (i.e., vaccination), chemical castration (e.g., zinc and calcium chloride neutering), and hormonal (e.g., GnRH) treatments has not yielded a consistently safe, efficacious, and marketable approved product for clinical use (14-16).
- Howe LM. Surgical methods of contraception and sterilization. Theriogenology 2016;66:500-509. Available from: https://www.ncbi.nlm.nih.gov/pubmed/16716381 Last accessed December 19, 2018.
- CVMA Veterinary Surgical Procedures – Position Statement. July 16, 2014. Available from: https://www.canadianveterinarians.net/documents/veterinary-surgical-procedures Last accessed December 19, 2018.
- Root Kustritz MV. Determining the optimal age for gonadectomy of dogs and cats. J Am Vet Med Assoc 2007;231:1665-1675. Available from: https://www.ncbi.nlm.nih.gov/pubmed/18052800 Last accessed December 19, 2018.
- Bushby PA, Griffin B. Veterinary medicine: An overview of pediatric spay and neuter benefits and techniques. dvm360 February 2011. Available from: http://veterinarymedicine.dvm360.com/overview-pediatric-spay-and-neuter-benefits-and-techniques Last accessed December 19, 2018.
- 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. Available from: https://www.ncbi.nlm.nih.gov/pubmed/11110455 Last accessed December 19, 2018.
- Spain CV, Scarlett JM, Houpt KA. Long-term risks and benefits of early-age gonadectomy in cats. J Am Vet Med Assoc 2004;224:372-379. Available from: https://www.ncbi.nlm.nih.gov/pubmed/14765796 Last accessed December 19, 2018.
- Neilson JC, Eckstein RA, Hart BL. Effects of castration on problem behaviors in male dogs with reference to age and duration of behavior. J Am Vet Med Assoc 1997;211:180-182. Available from: https://www.ncbi.nlm.nih.gov/pubmed/9227747 Last accessed December 19, 2018.
- Kutzler MA. Prostatic disease. In: Monnet E, ed. Small Animal Soft Tissue Surgery. Chichester, UK: John Wiley & Sons, 2012. Available from: https://onlinelibrary.wiley.com/doi/10.1002/9781118997505.ch66 Last accessed May 16, 2019.
- Hart BL, Hart LA, Thigpen AP, Willits NH. Neutering of German Shepherd Dogs: Associated joint disorders, cancers and urinary incontinence. Veterinary Medicine and Science 2016;2:191-199. Available from: https://onlinelibrary.wiley.com/doi/full/10.1002/vms3.34 Last accessed May 16, 2019.
- Gob CS. Age of Neutering in Large and Giant Breed Dogs. Clinicians Brief. August 2016:19-23. Available from: http://www.greysandstrays.com/uploads/6/1/0/6/61062155/amo_age_of_neutering_in_large-___giant-breed_dogs.pdf Last accessed May 16, 2019.
- Hart BL, Hart LA, Thigpen AP, Willits NH. Long-term health effects of neutering dogs: Comparison of Labrador retrievers with golden retrievers. PLoS ONE 2014;9:e102241. Available from: https://www.ncbi.nlm.nih.gov/pubmed/25020045 Last accessed May 16, 2019.
- Duffy DL, Serpell JA. Non-reproductive effects of spaying and neutering on behavior in dogs. AAC&D 3rd International Symposium on Non-Surgical Contraceptive Methods for Pet Population Control. Alexandria, Virginia. November 2006. Available from: https://www.acc-d.org/docs/default-source/3rd-symposium/duffy_abstract_ppt.pdf?sfvrsn=2 Last accessed May 16, 2019.
- Association of Shelter Veterinarians Position Statement. Early-Age Spay-Neuter of Dogs and Cats. February 2014. Available from: http://www.sheltervet.org/assets/docs/position-statements/earlyagespayneuter.pdf Last accessed December 19, 2018.
- Kutzler M, Wood A. Non-surgical methods of contraception and sterilization. Theriogenology 2006;66:514-525. Available from: https://www.ncbi.nlm.nih.gov/pubmed/16757019 Last accessed December 19, 2018.
- Root Kustritz MV. Nonsurgical contraceptives for dogs and cats (Proceedings). dvm360 May 2011. Available from: http://veterinarycalendar.dvm360.com/nonsurgical-contraceptives-dogs-and-cats-proceedings Last accessed December 19, 2018.
- Literature on Calcium Chloride Sterilization for Veterinarians. CaClCa. Available from: http://www.calciumchloridecastration.com/literature-calcium-chloride-sterilization-veternarians/ Last accessed December 19, 2018.
(Revised June 2019)
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