Chemical Castration in Dogs: A Comprehensive Guide

Nov 21, 2023 | Dog Behaviour

A landscape view of a veterinary clinic, with a calm and friendly dog lying on an operating table, surrounded by veterinary professionals preparing

Understanding Chemical Castration in Dogs

Chemical castration in dogs is a contemporary approach to dog sterilisation that’s gaining popularity among pet owners. This method involves the implantation of a hormonal chip, such as Suprelorin, under the dog’s skin. It’s a relatively simple procedure similar to microchipping and does not require anaesthesia, making it a less invasive alternative to traditional surgical neutering​​​​ and it is fully reversible.

Key TakeawaysDescription
What is Chemical CastrationA non-surgical, temporary method to sterilize male dogs using hormone implants
Duration of EffectivenessTypically lasts 6 or 12 months, depending on the implant used
Behavioural ChangesReduced sexual behaviours, less urine marking, and potential decrease in aggression
Side EffectsPossible swelling, changes in coat, and hormonal alterations
Comparing Chemical and Surgical CastrationChemical castration is reversible and does not require anaesthesia; surgical castration is permanent
Summary of Key Takeaways – Chemical Castration

How Chemical Castration Works

Chemical castration works by suppressing testosterone production in male dogs, either through hormonal implants or injections, resulting in temporary sterilisation.

Suppression of Testosterone Production

The process involves the suppression of testosterone production in male dogs, achieved by administering medication like gonadotropin-releasing hormone (GnRH) agonists.

These medications block testosterone, leading to a reduction in the dog’s sexual behaviour and fertility​​. Suprelorin, the most commonly used implant for this procedure, gradually releases Deslorelin, the active ingredient that suppresses testosterone production over time.

The Duration and Effectiveness

After the hormonal devices are in place, their job is to manage how long chemical castration will work. The length of time usually lasts either 6 or 12 months, depending on the type of implant used.

Dogs get an implant under their skin that slowly lets out a medicine called Deslorelin. It works by stopping testosterone from being made in their bodies.

Behavioural Changes and Side Effects

Dog owners often seek out chemical castration to address behavioural issues linked to male sex hormones, such as aggression, urine marking, and humping​​.

While it can significantly reduce such behaviours, it’s essential to understand that castration isn’t a substitute for proper training and socialisation. Additionally, some side effects, like changes in coat quality, appetite, and activity levels, might occur​​​​.

Surgical vs. Chemical Castration

Choosing between chemical and surgical castration depends on several factors. Including whether the dog owner intends to breed their pet in the future, concerns about permanent behavioural changes, and the dog’s health status.

One of the main benefits of chemical castration is it is fully reversible and does not require anaesthesia, which is beneficial for dogs that may have health issues making them unsuitable for surgery​​​​.

Chemical castration with hormone therapy like this gives owners a temporary and non-surgical choice for reproductive control in male dogs without lasting changes to their endocrine system.

Making the Right Decision

Before deciding on chemical castration, it’s crucial to weigh the pros and cons. It’s an ideal choice for dog owners who are considering breeding in the future or are unsure about making a permanent change.

Moreover, if the decision is against breeding, opting for castration, whether chemical or surgical, is advisable to prevent unwanted breeding and manage certain behavioural issues​​​​.

Pros and Cons of Chemical Castration

Chemical castration offers a temporary, non-invasive approach to dog sterilization, but it’s important to weigh the advantages and disadvantages before deciding.

Pros of Chemical CastrationCons of Chemical Castration
Non-surgical option reduces risk associated with anesthesia and surgery.Temporary solution requires repeated treatments over the dog’s lifetime.
Allows for future breeding as it is reversible.Less immediate compared to surgical castration; takes time to become effective.
Can help manage certain behaviors, such as aggression and roaming.Potential hormonal fluctuations could impact behavior unpredictably.
Eliminates the risk of testicular cancer.May not be as effective in reducing the risk of prostate disease compared to surgical neutering.
Effectiveness typically lasts for 6 to 12 months, providing flexibility.Cost can accumulate over time with the need for multiple treatments.

This table reflects key points to consider when contemplating chemical castration for dogs, highlighting both the potential benefits and the drawbacks of this method.

Chemical Castration for Golden Retriever

Factors to Consider Before Opting for Chemical Castration

Before opting for chemical castration for your dog, consider these important factors:

  1. Canine fertility control is a key consideration for dog owners thinking about future breeding or uncertain about permanent changes.
  2. The cost of chemical castration for dogs varies between £100 to £250 in the UK, depending on the vet and region, which should be weighed against other options.
  3. Ethical considerations in castrating dogs involve thoughtful reflection on whether chemical castration aligns with your values and the well-being of your pet.
  4. Consulting with a professional, such as a certified dog behaviourist and trainer, is crucial in making an informed decision about the best approach for your dog’s reproductive management and behavioral modification.
  5. Long-term impact of castration on dogs involves understanding its effects on hormone-driven behaviors and potential implications for anxiety and overall health.

The Impact of Chemical Castration on Dog Behaviour

Significantly influences certain behaviours in dogs. Behaviours driven by male sex hormones, like humping, urine marking, and aggression, may diminish after the procedure.

However, it’s crucial to remember that while this method can aid in reducing specific behaviours, comprehensive training and socialization are indispensable for overall behaviour management.

This is particularly relevant for dog owners dealing with reactive dog training, fear aggression, or resource guarding issues in their pets​​​​.

Key Takeaways on Neutering and Chemical Castration in Dogs

Key Takeaways on Neutering and Chemical Castration in Dogs

Behavioral Implications of Neutering and Anxiety in Dogs

Neutering can potentially increase fearfulness and anxiety in dogs, making a behavioural assessment crucial to determine if behaviours like roaming and excitability are influenced by testosterone. If these behaviours are testosterone-influenced, chemical castration using a deslorelin (Suprelorin) implant can be a viable option to assess its impact before considering permanent surgical castration.

Neutering Decisions in Rescue Organizations

Rescue organizations such as the RSPCA and Dogs Trust are adopting more individualized approaches to neutering, especially for male dogs showing fear and distress. These dogs are now often referred to behaviourists, with neutering decisions made on a case-by-case basis.

Neutering and Fear Behaviour Post-Surgery

Negative experiences during neutering, including inadequate pain management, can contribute to post-surgery fearfulness in animals. To mitigate this risk, it is recommended that pets have positive experiences at the vet’s kennels before elective surgery.

Health Risks Associated with Neutering

A study by Hart et al. (2020) indicates increased risks of joint disorders and urinary incontinence in neutered dogs, particularly larger breeds. It suggests waiting until dogs are skeletally mature before neutering to minimize these risks.

Castration and Aggressive Behavior

There are conflicting findings about the impact of castration on aggressive behaviour in dogs. Castration could be part of a treatment plan for behaviours likely influenced by testosterone, but it should be accompanied by behaviour modification strategies.

Health Concerns Related to Testosterone and Neutering

Testosterone’s role in bone, muscle development, and cognitive health is highlighted, along with risks like osteosarcoma associated with neutering. The decision to neuter should consider these factors and be made on an individual basis.

Neutering and IVDD Risk in Dachshunds

Neutering is associated with an increased risk of intervertebral disc disease (IVDD) in Dachshunds, and the recommendation is to delay neutering until they are at least a year old.

Neutering and Increased Fearfulness

Evidence suggests that neutering, particularly at a younger age, can be associated with increased fearfulness in both male and female dogs.

Entire Male Dogs and Targeted Aggression

There are anecdotal instances where entire male dogs have been targets of aggression from other male dogs, possibly due to negative associations or pheromonal cues.

Neutering’s Effect on Reactive Dog Behavior

Early neutering is associated with increased risk of fearfulness and aggressive behaviors, though the extent of its impact depends on various factors including genetics and early experiences.

Types of Fear Associated with Neutering

The document identifies various contexts of fearfulness in dogs post-neutering, including fear of unfamiliar situations, noise-related fear, and fear associated with handling and grooming.

Deslorelin (Suprelorin) Implant for Behavioural Assessment

Deslorelin implants are recommended for assessing the impact of testosterone reduction on behaviour in male dogs, especially if they are already fearful.

Enrichment and Training: Essential Complements

While chemical castration can be a helpful tool in managing certain undesirable behaviours, it should not be seen as a standalone solution. Regular enrichment activities for dogs are vital for their mental and physical well-being.

Additionally, understanding the role of epigenetics in animals and the impact of environment on behaviour is key.

Training, particularly in addressing issues like trigger stacking in dogs, remains crucial in developing well-adjusted pets​​.

Types of Aggression and Castration

Understanding the types of aggression in dogs is important when considering chemical castration. While it can reduce hormone-driven aggression, it may not be effective for all aggression types.

This is where understanding the difference between genetic and learned behaviours, as explained in Is Aggression Genetic or Learned?, becomes essential.

For comprehensive behaviour modification, a combination of training, socialisation, and in some cases, chemical castration, is advisable​​​​.

Training and Socialisation

The role of training and socialisation in a dog’s life cannot be overstated. These are critical components in managing and shaping dog behaviour. Chemical castration may aid in reducing some hormone-driven behaviours, but it’s not a substitute for good training practices.

Building a strong owner-dog bond and understanding the ethics and techniques of dog training are essential for a healthy and well-behaved pet​​.

Behavioural Implications of Neutering and Anxiety in Dogs

As we consider the influence of hormone-driven behaviours and their impact on dogs, it’s crucial to recognize the behavioral implications of neutering and anxiety. Neutering can potentially lead to an increase in fearfulness and anxiety in dogs, emphasizing the importance of a thorough behavioural assessment.

It’s essential to acknowledge that rescue organizations like RSPCA and Dogs Trust are shifting towards individualized approaches for neutering, particularly for male dogs exhibiting signs of fear and distress.

Neutering decisions are now being made on a case-by-case basis, often involving referrals to behaviourists for comprehensive assessments.

Furthermore, early neutering has been linked to heightened risks of fearfulness and aggressive behaviours in dogs; however, the extent of its impact varies based on factors such as genetics and early experiences.

Making Informed Decisions

In exploring the behavioural implications of neutering and anxiety in dogs, it becomes evident that making informed decisions about spaying or neutering is critical.

As pet owners contemplate these decisions, understanding that early neutering may carry an increased risk of fearfulness and aggression can guide them in seeking professional advice.

The evolving practices within rescue organizations underscore the necessity for personalised approaches when considering neutering options, especially concerning male dogs displaying fearful behaviour patterns.

Individualised Approaches to Neutering

Neutering decisions for dogs are now more tailored to each individual dog’s needs. Before opting for neutering, it’s crucial to consult a certified dog behaviorist and trainer. Behavioural assessment is essential in making the right decision, considering factors such as skeletal maturity and potential behavioural risks associated with early neutering.

For instance, a study by Hart et al. (2020) suggests waiting until larger breeds are skeletally mature before neutering due to increased risks of joint disorders and urinary incontinence.

Moreover, certain breeds like Dachshunds may be at higher risk of intervertebral disc disease if neutered too early, emphasizing the importance of an individualised approach when considering chemical castration in dogs.

Cost and Effectiveness of Chemical Castration

Cost in the UKBetween £100 to £250
Onset of EffectEffects start showing within a month of implantation
Full EffectivenessReached in about 4-6 weeks
DurationLasts for 6 to 12 months, based on the implant type
Behavioral ImpactReduction in hormone-driven behaviors, potentially lessening aggression and marking
ReversibilityNon-permanent, less invasive than surgical neutering

Chemical Castration in Dogs: Is It Worth It?

Administering the Suprelorin implant is an increasingly popular option for managing reproduction and certain behaviours in male dogs. While it offers a less invasive and reversible alternative to surgical castration.

It is important to consider it as part of a broader approach to dog care.

Consulting with a professional, such as a dog behaviourist, is crucial in making an informed decision about the best approach for your dog.

About Me

Jim Gillies, a Certified Dog Behaviourist and Trainer in Glasgow with over 10 years of experience, prioritises canine well-being through modern, science-backed methods. Handling 4000+ cases of 1-to-1 behaviour training, Jim is fully accredited, insured, and recognised for addressing various behavioural issues including aggression, separation anxiety, and more. Jim holds qualifications in level 5 (merit) Advance Diploma Canine Behaviour Management and level 6 Applied Animal Behaviour. Explore his insightful blog and podcast, sharing expert knowledge on dog training and behaviour. Certified by the IAABC, Jim’s expertise makes him a reliable choice for addressing your dog’s needs.

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Chemical Castration in Dogs – FAQ

Frequently Asked Questions About Chemical Castration in Dogs

Q: How much is chemical castration for dogs in the UK?
A: The cost of chemical castration for dogs in the UK varies but typically ranges from £100 to £250, depending on the vet and the region.
Q: How long does chemical castration take to work in dogs?
A: Chemical castration usually starts to show its effects within a month of implantation, with full effectiveness reached in about 4-6 weeks.
Q: What is chemical castration in dogs?
A: Chemical castration in dogs involves using a hormonal implant to temporarily suppress testosterone production, reducing fertility and certain behaviors influenced by male hormones.
Q: Can you chemically castrate a dog?
A: Yes, dogs can be chemically castrated using hormonal implants such as Suprelorin, which is a safe and reversible method.
Q: Does chemical castration work in dogs?
A: Yes, chemical castration is effective in reducing testosterone-driven behaviors and temporary infertility in dogs.
Q: How does chemical castration work in dogs?
A: Chemical castration works by implanting a hormone-releasing device under the dog’s skin, which gradually releases a substance that suppresses testosterone production.
Q: How long does chemical castration last in dogs?
A: The effects of chemical castration in dogs typically last for 6 to 12 months, depending on the type of implant used.
Q: How much does chemical castration cost for dogs?
A: The cost for chemical castration in dogs can range from approximately £100 to £250, depending on various factors such as location and veterinary practice.
Q: Is chemical castration safe for dogs?
A: Yes, chemical castration is generally safe for dogs. It is a non-invasive procedure with few side effects, but a veterinary consultation is recommended.
Q: Can a 9-year-old dog have chemical castration?
A: Yes, older dogs can undergo chemical castration, but a vet should assess their overall health to ensure they are suitable candidates.
Q: Can a dog mate a bitch after chemical castration?
A: While chemical castration reduces fertility, it’s advisable to keep a chemically castrated dog away from females in heat during the initial weeks post-implantation.
Q: Does chemical castration help in humping behaviors in adolescent dogs?
A: Yes, chemical castration can help reduce humping and other sexual behaviors in adolescent dogs by lowering testosterone levels.
Q: Does chemical castration reduce testicle size in dogs?
A: Yes, one of the effects of chemical castration can be a reduction in testicle size due to decreased testosterone production.


Hart et al. (2020)
Assisting Decision-Making on Age of Neutering for 35 Breeds of Dogs: Associated Joint Disorders, Cancers, and Urinary Incontinence.
View Article
The chemical castration chip for non-surgical dog castration.
View Article
Understanding Chemical Castration for Dogs.
View Article
Suprelorin® – Surgery-free alternative for dog castration.
View Article

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