Open Veterinary Journal, (2025), Vol. 15(6): 2284-2285

Letter to the Editor

10.5455/OVJ.2025.v15.i6.2

Determining the earliest age for neutering and spaying specific companion dogs

Krishna Prasad Acharya^1*, Sarita Phuyal², Lynette Arnason Hart³ and Benjamin L. Hart³

¹Animal Disease Investigation and Control Division (ADICD), Department of Livestock Services (DLS), Lalitpur, Nepal

²Department of Livestock Services (DLS), Central Referral Veterinary Hospital (CRVH), Kathmandu, Nepal

³School of Veterinary Medicine, University of California, Davis, CA, USA

*Corresponding Author: Krishna Prasad Acharya. Animal Disease Investigation and Control Division (ADICD), Department of Livestock Services (DLS), Lalitpur, Nepal. Email: kpa26 [at] cantab.ac.uk

Submitted: 02/05/2025 Revised: 23/05/2025 Accepted: 29/05/2025 Published: 30/06/2025

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Dear Editor

Neutering (including spaying) has now become a widely used population control measure for companion animals. Dogs and cats as young as 8 weeks of age are neutered, often the majority of them at 4–6 months of age (Howe, 2015; Oliveira-Martins et al., 2023). Many owners prefer to neuter their animals at an early age because it is easier to perform the surgery and leads to less pain and faster healing as compared to adults. However, in recent years, concerns have been raised due to health complications associated with early gonadectomy. Research has shown that joint disorders, hemangiosarcoma, mast cell tumor, lymphoma, osteosarcoma, and cognitive impairment are sometimes linked to spay/neuter before 1 year of age (Hart et al., 2020a, 2024). Such early-age spay/neuter involves the removal of the gonads, which stops the secretion of the hormones, such as testosterone and estrogen that are necessary for normal bodily functions and overall health. Recent evidence has shown that for many larger dogs, a better time for neutering the animal would be when the animal is at least through puppyhood and the growth of the long bones is completed so that the increased risk of health problems such as joint disorders sometimes associated with early-age neutering would not occur. Some evidence has shown that dogs weighing less than 20 kg can be neutered from 6 months of age without increased risk of joint disorders (American Animal Hospital Association, 2019; Anon, 2023). However, for dogs with a predicted body weight exceeding 20 kg, it is better to wait until they are at least 12 months of age (Hart et al., 2020b; Anon, 2023), and for those over 40 kg, it may be better to wait until 24 months of age (Anon, 2023) to reduce the risk of joint disorders such as elbow or hip dysplasia or cranial cruciate ligament tear or rupture (Hart et al., 2020b). In addition to increasing the likelihood of obesity, recent studies have also revealed that neutering dogs or shortening their exposure to gonadal hormones increases the risks of behavior problems such as fear aggression (Farhoody et al., 2018; McGreevy et al., 2018; Starling et al., 2019) and other health problems (Oberbauer et al., 2019; Zink et al., 2023). It has been suggested that the increased rates of various diseases are caused by the prolonged highly elevated LH secretion that follows gonad removal (Kutzler, 2020). Considering this scientific evidence, a charity in the UK, the Royal Society for the Prevention of Cruelty to Animals has changed its neutering policy (Hatton, 2023). However, other charity organizations and stakeholders performing neutering seem not to have modified their early-neutering policies. The early-age neutering of companion dogs prior to adoption from shelters is often required, as in the state of California (2023 California Food & Agricultural Code, 2023), despite the increased risk of becoming large dogs. This complexity suggests that the entire situation and social context for each dog should be considered when deciding about neutering, also recognizing the challenges in communities where many dogs run free. Therefore, it is necessary to adopt a new paradigm, predefining the earliest age to consider neutering for a specific dog based on its breed and likely adult body weight to prevent undue health risks from early-age neutering, with cautionary consideration of possible problems that may arise with intact dogs in the local context.

Conflict of interest

None.

Author’s contribution

KPA conceived the concept; KPA and SP drafted the initial manuscript while all authors contributed significantly to revising this for submission. All authors agreed on the final version for submission to the journal.

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References

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