By Norma Jeanne Laurette

​There is unquestionably no doubt that there are too many unwanted dogs in the world. It absolutely breaks my heart to see so many homeless dogs on the streets or trapped in cages at shelters for extended periods of time, not to mention all the deserving and amazing dogs (all of them) that are being euthanized due to lack of space. The World Health Organization estimates that there are more than 200 million stray dogs in the world R1 and in North America alone, millions of dogs are in shelters every year, with hundreds of thousands euthanized due to overcrowding R2. These numbers stress just how important it is to rescue or adopt whenever possible and take steps to prevent the reproduction of unwanted dogs.

We know that spay and neuter can be part of the solution but is it detrimental to our dog’s health and wellbeing? Our dogs are not just pets, they are members of the family and as such, we want what’s best for them, including good health and longevity. The reality is that while beneficial at controlling overpopulation, spay and neuter procedures come with risk to our dogs. This decision is not one to be made lightly and many guardians including Greg and I have struggled to make the right choice.

​The most obvious benefit of spaying and neutering is the prevention of unwanted puppies. A single intact female can have two litters per year and one intact male can father hundreds of puppies over his lifetime. Spaying and neutering helps prevent accidental breeding and directly reduces the number of unwanted dogs R3. It prevents the suffering of countless puppies and adult dogs that would otherwise be forced into a hard life on the streets, spending their lives in a cage or being prematurely euthanized due to overcrowding.

From a medical standpoint, there are benefits for females. Female dogs left intact run a 26% risk of developing mammary cancer R29 and spaying before her first heat cycle reduces that risk to less than one percent. If she is spayed after her first heat, the risk increases to about 8% and after the second heat cycle it jumps to approximately twenty-six percent R4. Pyometra, a life-threatening uterine infection is also eliminated when the uterus is removed R29. 

For male dogs, neutering eliminates their 14% chance of developing testicular cancer and greatly reduces the risk of benign prostatic hyperplasia, which can cause discomfort, infections and urinary obstruction R5. The risk for BPH in intact males is 50% by 5 years of age and 95% at nine years or older.

Behavioural changes are another potential advantage of neutering male dogs. Neutered males are less prone to marking territory, roaming when they smell a female in heat and engaging in inter-male aggression in the presence of females in heat. It can also help reduce the risk of dogs escaping when they smell a female in heat and becoming lost, kidnapped, injured or killed R6.

​In spite of the benefits, these procedures are not without risk. With any surgery there is always a chance of complications or death from anaesthesia, infections and pain and suffering after surgery, not to mention a potentially traumatic experience at the vet clinic R7. 

Science has proven that there are potential long-term health issues in spayed and neutered dogs. Studies have shown that early spay or neuter, which is considered anything up to 6 months of age can increase the risk of certain cancers including osteosarcoma (bone cancer), hemangiosarcoma (cancer of the blood vessel cells) and lymphoma (cancer of lymphocytes), especially in large and giant breed dogs R8. 

Orthopedic problems such as hip dysplasia and cranial cruciate ligament rupture have also been linked to early spay and neuter. Reproductive hormones are important to skeletal development and removing them before the growth plates have closed can predispose dogs to structural problems later in life R9.

Spayed and neutered dogs are more likely to develop hypothyroidism, which can lead to lethargy, skin issues and infections, hair loss, cold intolerance, slowed heart rate, weight gain, weakness, lethargy, loss of coordination, seizures, depression and anxiety R20. 

After spay or neuter, a dog’s metabolism changes and they may require 20 to 30% fewer calories to maintain a healthy weight R10. Without proper adjustments to diet and exercise, many spayed or neutered dogs become overweight, increasing their risk for diabetes, arthritis and cardiovascular problems.

​The risks associated with early sterilization are higher in large and giant breed dogs. Removing the reproductive hormones before the growth plates have closed changes bone development and can lead to abnormal limb alignment, cruciate ligament injury and hip dysplasia R15. 

Hormones such as estrogen and testosterone also contribute to immune regulation, metabolism and cognitive function R16. Early spaying or neutering can subtly affect brain development and cognitive function in dogs by removing hormones that support neurodevelopment, metabolism and immune regulation R36. Interrupting these processes too early can leave a dog vulnerable to long-term health and learning challenges R36. 

Female dogs spayed at a very young age have also proven to have an increased risk of urinary incontinence, especially when surgery is performed before three months of age R19. 

While neutering often decreases escaping, roaming, and sexual behaviours, its impact on aggression is more complex. While some studies suggest that neutering can reduce inter-male aggression, others suggest it can also increase fear and fear aggression in some dogs, especially when dogs are traumatized during the vet visit for the procedure R23.

​Some studies show that intact male dogs can exhibit an increase in certain types of aggression however, proving causation is difficult because aggression is influenced by many factors including genetics, experiences, socialization, environment and training. Since most of these studies are survey-based, and because people are unreliable observers knowing very little about canine behaviour and aggression, it’s my opinion that these results are questionable.

Some studies report that 6 to 8% of intact males show aggression toward their guardians compared to 4 to 6% of neutered dogs, and that 10 to 12% of intact males show aggression toward strangers compared to 7 to 9% of neutered dogs R31. 

They state that 15 to 20% of intact males are likely to display aggression toward other male dogs, particularly in situations involving competition for females in heat, territory or resources R31. Testosterone is believed to play a role in aggression associated with mating in 25 to 40% of intact males as well as in 20 to 30% associated with competition, especially over food, toys and resting places. They report that this can lead to confrontations with other male dogs and increased territorial behaviours toward unfamiliar dogs or people R32 R33.

That said, causation that testosterone alone is responsible for these behaviours cannot be proven through surveys and reducing aggression is never guaranteed by neutering the dog. Aggression in any dog can have multiple contributors and is best addressed through prevention and early intervention, through a pleasant and thorough socialization, consistent positive training and environmental management. 
​
When dealing with any type of aggression, the possibility of pharmaceutical and physiological causes or contributors other than testosterone such as imbalances in brain chemistry, endocrine disorders, pain or neurological abnormalities must also be considered. For more information about physiological and pharmaceutical causes of aggression, see my article Canine Aggression – Physiological & Pharmaceutical Causes.

My point is that genetics, breed, experiences, socialization, training and environment are much stronger predictors of aggression than reproductive status alone. Approximately 90% of intact males live peacefully without ever showing aggression toward people and 60 to 75% around females in heat. 
​
Because most of these studies rely on surveys and most people are unqualified to assess canine aggression, I believe that of the small percentage that do show aggression toward people, most of these cases would at least have contributors, if not causes other than testosterone and if the dog never has the opportunity to be around other intact males and a female in heat, it’s a moot point.

​For decades, veterinarians have commonly recommended sterilization at approximately six months of age but research has shown that the “one-size-fits-all” approach is not appropriate. When choosing to spay or neuter a dog, the best timing depends on the dog’s breed, size, health status and health risk R11.

Smaller breeds tend to mature earlier and appear less susceptible to orthopedic problems when sterilized before one year of age. For example, Chihuahuas and Yorkshire Terriers show a minimal increase in orthopedic risk when neutered early R14. On the other hand, larger breeds such as Golden Retrievers, Labrador Retrievers and German Shepherds are significantly more prone to joint disease when neutered before their bones have fully matured R12 R21.

In female dogs, each heat cycle increases the chance of mammary cancer, but delaying spay surgery until after the first or even second heat may allow for healthier bone and joint development R13. This means that guardians need to weigh the risks of mammary cancer against the risks of orthopedic disease. 

For small and medium breeds, mammary cancer is the greater risk meaning that spay/neuter before the first heat is safest. For large breeds, orthopedic/joint disease is the greater risk meaning that spay/neuter between 12 and 18 months of age comes with the least risk R13.

For males, delaying neuter until after growth plates have closed provides musculoskeletal benefits, but doing so could temporarily increase the chance of unwanted mating. Again, if the dog has no access to females in heat this is not an issue.

​Spay & Neuter

While Maintaining Hormonal BalanceWhile spay and neuter remain the most common methods of sterilization, other options are now available. For example, a vasectomy prevents reproduction in male dogs while leaving testosterone intact, preserving its protective effects on bone and metabolic health R24 and an ovary-sparing spay removes the uterus while leaving the ovaries, preventing pyometra while maintaining hormonal balance R25.

Chemical Sterilization

Chemical sterilization is another option that’s being tested in some regions. Zinc gluconate injections can sterilize male dogs without surgery, though the procedure is not yet widely available in North America. However, be aware that chemical sterilization comes with potential hormonal, behavioural and metabolic risks and the long-term consequences are not yet known R26.

Hormone-Based Contraceptive Implants

In some parts of Europe, vets already use hormone implants such as Deslorelin to temporarily stop dogs from having puppies, while leaving the option of having it reversed at a later date. Again, hormone-based contraceptive implants can cause injection-site reactions, temporary behaviour changes, metabolic disturbances, reproductive irregularities and potential long-term effects on hormone-dependent tissues. In my opinion, the use of chemical sterilization and hormone implants is simply trading one set of risks for another.

Leaving Your Dog Intact

Choosing not to sterilize a dog can offer several benefits for their long-term health and wellbeing. Intact dogs retain the natural balance of sex hormones, which support normal growth, metabolism, immune function and neurodevelopment R38 R42.

For females, remaining intact eliminates surgical risks such as anesthesia complications, infection and pain after the procedure. It also reduces the risk of certain orthopaedic issues associated with early spay such as delayed growth plate closure and allows for natural reproductive cycles that can be monitored for overall health R42.

For males, avoiding neuter eliminates surgical risks such as anesthesia complications, infection and pain after the procedure. It helps maintain normal testosterone-driven musculoskeletal development and can support cognitive and behavioural stability R38 R40. It also preserves the dog’s natural hormone-dependent behaviours, which can be important for socialization and environmental awareness R39 R41.

​Keeping a dog healthy and well behaved while leaving them intact requires a proactive approach to physical and behavioural health. One of the most important aspects of both is to provide a natural balanced diet and regular exercise to give them the best chance at overall health and wellness R44 R45. 

Greg and I always recommend raw feeding because all processed kibble contains low-nutrient fillers and/or harmful ingredients, which can lead to a wide range of health issues including but not limited to allergies, bone and joint problems, gastrointestinal issues, behaviour problems, cancer and a shortened lifespan R48. For more information about nutrition and the dangers of processed dog food see my article Canine Nutrition – Essential For Your Dog’s Health & Longevity. 

Behavioural management is equally important and requires consistent positive training, socialization with suitable dogs, people and environments as well as outlets for their natural instincts such as supervised play, exploring natural environments and lots of sniff time on walks. Other options include canine enrichment, such as social, physical, handling, cognitive, feeding and sensory activities. All of these options help to prevent boredom, frustration, stress, anxiety, fear and unwanted behaviours including aggression R46 R47. For more information about canine enrichment see my article Canine Enrichment For Dogs.

For intact dogs, it’s important to monitor reproductive cycles in females and territorial behaviour in males. Environmental management, including controlled access when a female is in heat and providing appropriate outlets for male energy, is essential R43 R44. Equally important is ensuring that the home and yard are secure to prevent escape. With preventive healthcare, proper nutrition, regular exercise, socialization, positive training and enrichment, guardians can help intact dogs stay safe, healthy, mentally stimulated and well-adjusted R45 R47.

​In spite of the choice each guardian makes, it goes without saying that responsible ownership is essential. Those who choose to keep their dogs intact need to take strict precautions to prevent accidental breeding such as secured doors, fencing and gates, supervision during walks and proactively keeping intact males away from females in heat. Lifestyle and family dynamics also play a role as active, mature and experienced households with well-trained dogs are more likely to successfully manage intact pets, while less structured households with irresponsible adults or young children can find it more difficult to keep their dogs safely confined to prevent unwanted pregnancies.

​Deciding whether to spay or neuter is a personal choice and not an easy one. Greg and I have spent a lot of time researching and discussing our options. While sterilization can help prevent overpopulation and reduce the suffering of unwanted dogs, each guardian has to weigh risk versus reward for their dogs and themselves. Our dogs depend on us not only for food, shelter and companionship but also to make responsible decisions that will affect the rest of their lives. With careful consideration, we can make choices that support a society that does not contribute to the problem of unwanted dogs, while ensuring our dogs live long, healthy and happy lives.

R1: World Health Organization. (2019). Rabies and responsible dog ownership. WHO. Global estimates of stray dog populations and public health concerns.
R2: American Society for the Prevention of Cruelty to Animals. (2022). Pet statistics. ASPCA. Provides U.S. shelter intake and euthanasia statistics.
R3: American Veterinary Medical Association. (2020). Dog overpopulation and spay/neuter. AVMA. Overview of population control benefits.
R4: Schneider, R., Dorn, C. R., & Taylor, D. O. (1969). Factors influencing canine mammary cancer development and postsurgical survival. Journal of the National Cancer Institute, 43(6), 1249–1261.
R5: Teske, E., Naan, E. C., van Dijk, E. M., Van Garderen, E., & Schalken, J. A. (2002). Canine prostate carcinoma: Epidemiological evidence of an increased risk in castrated dogs. Molecular and Cellular Endocrinology, 197(1–2), 251–255.
R6: Neilson, J. C., Eckstein, R. A., & Hart, B. L. (1997). Effects of castration on problem behaviors in male dogs with reference to age and duration of behavior. Journal of the American Veterinary Medical Association, 211(2), 180–182.
R7: Howe, L. M. (2006). Surgical methods of contraception and sterilization. Theriogenology, 66(3), 500–509.
R8: Cooley, D. M., Beranek, B. C., Schlittler, D. L., Glickman, N. W., Glickman, L. T., Waters, D. J. (2002). Endogenous gonadal hormone exposure and bone sarcoma risk. Cancer Epidemiology Biomarkers & Prevention, 11(11), 1434–1440.
R9: Torres de la Riva, G., Hart, B. L., Farver, T. B., Oberbauer, A. M., & Hart, L. A. (2013). Neutering dogs: Effects on joint disorders and cancers in Golden Retrievers. PLOS ONE, 8(2), e55937.
R10: McGreevy, P. D., & Masters, A. M. (2008). Risk factors for obesity in dogs in Australia. Journal of Veterinary Internal Medicine, 22(3), 638–643.
R11: Spain, C. V., Scarlett, J. M., & Houpt, K. A. (2004). Long-term risks and benefits of early-age gonadectomy in dogs. Journal of the American Veterinary Medical Association, 224(3), 380–387.
R12: Hart, B. L., Hart, L. A., Thigpen, A. P., Willits, N. H. (2020). Assisting decision-making on age of neutering for 35 breeds of dogs: Associated joint disorders, cancers, and urinary incontinence. Frontiers in Veterinary Science, 7, 388.
R13: Beauvais, W., Cardwell, J. M., & Brodbelt, D. C. (2012). The effect of neutering on the risk of mammary tumours in dogs—A systematic review. Journal of Small Animal Practice, 53(6), 314–322.
R14: Salmeri, K. R., Bloomberg, M. S., Scruggs, S. L., & Shille, V. M. (1991). Gonadectomy in immature dogs: Effects on skeletal, physical, and behavioral development. Journal of the American Veterinary Medical Association, 198(7), 1193–1203.
R15: Hart, B. L., Thigpen, A. P., Willits, N. H., & Hart, L. A. (2014). Long-term health effects of neutering dogs: Comparison of Labrador Retrievers with Golden Retrievers. PLOS ONE, 9(7), e102241.
R16: Root Kustritz, M. V. (2007). Determining the optimal age for gonadectomy of dogs and cats. Journal of the American Veterinary Medical Association, 231(11), 1665–1675.
R17: Olson, P. N., & Moulton, J. E. (1993). Pet overpopulation: A clinical perspective. Iowa State University Press. Discusses risks of delayed sterilization.
R18: Hughes, K. L., & Slater, M. R. (2002). Implementation of a feral cat management program on a university campus. Journal of Applied Animal Welfare Science, 5(1), 15–28. (Used here for public health links to sterilization programs).
R19:  Thrusfield, M. V., Holt, P. E., & Muirhead, R. H. (1998). Urinary incontinence in bitches: Prevalence and relationship to neutering status. Journal of Small Animal Practice, 39(12), 559–566.
R20: Panciera, D. L. (1994). Hypothyroidism in dogs: 66 cases (1987–1992). Journal of the American Veterinary Medical Association, 204(5), 761–767.
R21: Zink, M. C., Farhoody, P., Elser, S. E., Ruffini, L. D., Gibbons, T. A., & Rieger, R. H. (2014). Evaluation of the risk and age of onset of cancer and behavioral disorders in gonadectomized Vizslas. Journal of the American Veterinary Medical Association, 244(3), 309–319.
R23: Farhoody, P., Mallawaarachchi, I., Tarwater, P. M., Serpell, J. A., Duffy, D. L., & Zink, C. (2018). Aggression toward familiar people, strangers, and conspecifics in gonadectomized and intact dogs. Frontiers in Veterinary Science, 5, 18.
R24: Romagnoli, S. E. (2008). Surgical contraception in dogs and cats: What’s new? Reproduction in Domestic Animals, 43(2), 144–149.
R25: Wallace, M. S. (2019). Ovary-sparing spay in dogs: Techniques and outcomes. Veterinary Surgery, 48(7), 1132–1140.
R26: Levy, J. K., Crawford, P. C., Appel, L. D., & Clifford, E. L. (2008). Comparison of intratesticular injection of zinc gluconate versus surgical castration to sterilize male dogs. Theriogenology, 70(1), 151–157.
R27: Trigg, T. E., Wright, P. J., Armour, A. F., Williamson, P. E., Junaidi, A., Martin, G. B., & Doyle, A. G. (2001). Use of a GnRH analogue implant to produce reversible long-term suppression of reproductive function in male and female dogs. Journal of Reproduction and Fertility Supplement, 57, 255–261.
R28: Sandøe, P., Corr, S., Palmer, C., & Bjørnvad, C. R. (2016). Canine and feline welfare in relation to obesity and neutering. Animal Welfare, 25(2), 125–138.
R29: Sorenmo, K. U. (2003). Canine mammary gland tumors. Veterinary Clinics of North America: Small Animal Practice, 33(3), 573–596. Elsevier. Overview of incidence, risk factors, and treatment, including how spaying affects mammary cancer risk in dogs.
R30: Pechman, R. D., & Mathews, K. G. (1996). Canine testicular tumors: Prevalence and clinical presentation. Journal of the American Animal Hospital Association, 32(4), 289–293. Study on incidence, tumour types, and outcomes in intact male dogs, confirming testicular tumours as one of the most common neoplasms with a prevalence of about 14% in intact males.
R31: Neilson, J. C., Eckstein, R. A., & Hart, B. L. (1997). Effects of castration on problem behaviors in male dogs with reference to age and duration of behavior. Journal of the American Veterinary Medical Association, 211(2), 180–182. Study showing neutering can reduce testosterone-related aggression in male dogs, especially toward other males.
R32: Salmeri, K. R., Bloomberg, M. S., Scruggs, S. L., & Shille, V. M. (1991). Gonadectomy in immature dogs: Effects on skeletal, physical, and behavioral development. Journal of the American Veterinary Medical Association, 198(7), 1193–1203. Highlights the role of testosterone in male aggression and territorial behavior.
R33: Hopkins, S. G., & Schubert, T. A. (2005). The effects of gonadectomy on canine behavior. Veterinary Clinics of North America: Small Animal Practice, 35(2), 287–303. Discusses increased resource guarding in intact male dogs and behavioral implications.
R34: Casey, R. A., Loftus, B., Bolster, C., Richards, G. J., & Blackwell, E. J. (2014). Human directed aggression in domestic dogs (Canis familiaris): Occurrence in different contexts and risk factors. Applied Animal Behaviour Science, 152, 52–63. Notes that fear and anxiety-based aggression are independent of gonadal status.
R35: Spain, C. V., Scarlett, J. M., & Houpt, K. A. (2004). Long-term risks and benefits of early-age gonadectomy in dogs. Journal of the American Veterinary Medical Association, 224(3), 380–387. Examines behavioral effects of neutering and cautions against expecting universal reductions in aggression.
R36: Hart, B. L. (2001). Effect of gonadectomy on subsequent development of age-related cognitive impairment in dogs. Journal of the American Veterinary Medical Association, 219(1), 51–56.
R37: Kost, L. V., et al. (2025). Possible side effects of hormonal castration in a dog. PubMed Central.
R38: Parsemus Foundation. (n.d.). How Spay & Neuter Affect Health. Retrieved from https://www.parsemus.org/project/how-spaying-and-neutering-affect-health/
R39: American Kennel Club. (2024, March 22). Should You Always Spay-Neuter Your Dog?. Retrieved from https://www.akc.org/expert-advice/health/should-you-spay-neuter-dogs/
R40: Whole Dog Journal. (n.d.). Keeping Your Dog Intact. Retrieved from https://www.whole-dog-journal.com/health/spay-neuter/keeping-your-dog-intact/
R41: Understanding Animal Research. (2020, February 25). The benefits and risks of neutering pets. Retrieved from https://www.understandinganimalresearch.org.uk/news/neutering-and-cancer-the-good-the-bad-and-the-ugly
R42: Zink, M. C., & Roush, J. K. (2013). The effects of early spay/neuter on the risk of joint disorders and cancers in Golden Retrievers. Frontiers in Veterinary Science, 1, 1–7. https://doi.org/10.3389/fvets.2013.00001
R43: American Veterinary Medical Association. (2023). Preventive care for dogs. Retrieved from https://www.avma.org/resources/pet-owners/petcare/preventive-care-dogs
R44: Parsemus Foundation. (n.d.). How Spay & Neuter Affect Health. Retrieved from https://www.parsemus.org/project/how-spaying-and-neutering-affect-health/
R45: Zink, M. C., & Roush, J. K. (2013). The effects of early spay/neuter on the risk of joint disorders and cancers in Golden Retrievers. Frontiers in Veterinary Science, 1, 1–7. https://doi.org/10.3389/fvets.2013.00001
R46: American Kennel Club. (2024). Training and socialization tips for dogs. Retrieved from https://www.akc.org/expert-advice/training/
R47: Whole Dog Journal. (n.d.). Keeping your dog mentally and physically stimulated. Retrieved from https://www.whole-dog-journal.com/behavior/mental-stimulation-for-dogs/
R48: European Food Safety Authority. (n.d.). Scientific opinions on various food and feed additives. Retrieved from https://efsa.europa.eu
R49: de la Riva, G. T., et al. (2013). “Neutering Dogs: Effects on Joint Disorders and Cancers in Golden Retrievers.” PLOS ONE. Available at: https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0055937
R50: Robinson, K. L., et al. (2020). “An age and time-period matched case-control study.” PMC. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC7155881/
R51: Joonè, C. J., et al. (2023). “The effect of neuter status on longevity in the Rottweiler dog.” PMC. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC10587138/
R52: Howe, L. M., et al. (2015). “Current perspectives on the optimal age to spay/castrate dogs.” PMC. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC6070019/
R53: Loudon, D. (2024). “The Heartbreak of Hemangiosarcoma in Dogs.” Available at: https://drloudon.com/pet-health/the-heartbreak-of-hemangiosarcoma-in-dogs/
R54: Hart, B. L., et al. (2020). “Assisting Decision-Making on Age of Neutering for 35 Dog Breeds.” PMC. Available at: https://www.frontiersin.org/articles/10.3389/fvets.2020.00388/full
R55: American Kennel Club Canine Health Foundation. “Bone Cancer in Dogs.” Available at: https://www.akcchf.org/disease-history/bone-cancer-in-dogs/
R56: Parsemus Foundation. “Advances in Understanding Cancer in Dogs: Hemangiosarcoma in Golden Retrievers.” Available at: https://www.parsemus.org/2024/02/advances-in-understanding-cancer-in-dogs-hemangiosarcoma-in-golden-retrievers/
R57: Hart, B. L., & Hart, L. A. (2020). Assisting Decision-Making on Age of Neutering for 35 Dog Breeds.
R58: Frontiers in Veterinary Science. This study provides breed-specific guidelines on the optimal timing for neutering to minimize health risks.
R59: Oberbauer, A. M. (2019). A Review of the Impact of Neuter Status on Expression of Disease in Dogs.
R60: Frontiers in Veterinary Science. This review summarizes the effects of neutering on cancer, orthopedic, and immune disorders in dogs.
R61: UC Davis Veterinary Medicine (2024). When Should You Neuter or Spay Your Dog?
This article discusses updated guidelines for neutering dogs to decrease the risk of certain cancers and joint disorders.
R62: American Kennel Club Canine Health Foundation (2024). What Is the Best Age to Spay/Neuter Your Dog? It Depends. This resource provides insights into how neutering timing affects long-term health in dogs.
R63: Parsemus Foundation (2025). How Spay & Neuter Affect Health. This article examines the health impacts of spaying and neutering, including potential risks and benefits.

Photo By Norma Jeanne Laurette

By Norma Jeanne Laurette

​The choice between feeding dogs a raw diet or commercial dog food is one of the most debated topics in canine nutrition. Many guardians favour raw diets over processed foods because they closely resemble a dog’s natural, ancestral diet and are healthier for the dog. Raw feeding improves coat condition, boosts energy levels, promotes dental health, maintains lean body weight and supports overall wellness. Raw feeding can also help prevent a wide range of diseases and behaviour problems associated with poor nutrition and toxins found in processed dog foods R1 R3 R4. Understanding the potential risks and benefits of both approaches is essential to making a responsible choice that impacts our dogs’ health, longevity and quality of life.

​In Belleville, Ontario, we source our raw dog food from Furball’s Choice, located at 1-300 Bell Blvd. They also operate local delivery routes (Belleville/GTA, etc.), provide bi-weekly GTA deliveries and maintain a network of independent distributors across Canada. To find a location near you, call 613-743-3600 or visit their website.

Our preferred product is their House Blend, packaged in bags containing 1 lb frozen bricks that can be thawed as needed. This blend offers a balanced mix of proteins, bones and organs to meet your dog’s nutritional needs and is made up of 40% chicken, 25% beef (including red meat, heart, green tripe and bone), 10% offal (liver, kidney and other internal organs), 20% pickerel and 5% cooked eggs. For more information about their House Blend and other available products, visit https://furballschoice.com/

​Choosing between raw feeding and processed food involves carefully weighing the risks and rewards of each approach, taking into account a dog’s individual needs as well as ensuring safety and nutritional balance. A properly planned raw diet will provide essential nutrients for optimal health while minimizing many of the risks associated with processed foods. Informed choices are essential for guardians who wish to support their dog’s overall health, longevity and quality of life.

​The information in these chapters is for educational and informational purposes only and reflects the author’s research and opinions. It includes information from pet food websites, pet food industry critiques and advocacy materials from natural/raw diet promoters, consumer reports and anecdotal evidence from pet owners. It also includes selective interpretations of scientific research and regulatory data, concerns from special interest groups including holistic veterinarians and alternative pet food companies, veterinary nutrition papers and independent testing on ingredient quality and processing effects. It is not veterinary, nutritional or professional advice. When making nutritional choices or changes to your dog’s diet, you are advised to consult with a qualified, professional, canine nutrition expert. Readers assume full responsibility for their decisions. References to specific products or companies are for critical discussion only.

R1: MetLife Pet Insurance. (2022). Pros and Cons of a Raw Food Diet for Dogs. Retrieved from [https://www.metlifepetinsurance.com/blog/pet-care/raw-food-diet-for-dogs/]
R2: American Kennel Club. (2019). Fresh vs Raw Dog Food vs Kibble: Which Diet Is Best For Your Dog? Retrieved from [https://www.akc.org/expert-advice/nutrition/fresh-raw-kibble-dog-food/]
R3: Big Dog Pet Foods. (n.d.). DIY Balanced Raw Food Diets. Retrieved from [https://www.bigdogpetfoods.com/guides/diy-balanced-raw-food-diets]
R4: The Dog’s Butcher. (n.d.). Fruit and Vegetables in a Raw Diet. Retrieved from [https://www.thedogsbutcher.co.uk/pages/fruit-and-vegetables-in-a-raw-diet]
R5: PetMD. (2014). The Risks and Benefits of Raw Meat Diets for Dogs. Retrieved from [https://www.petmd.com/blogs/nutritionnuggets/dr-coates/2014/march/risks-and-benefits-raw-meat-diets-dogs-31455]
R6: WebMD. (2024). Raw Dog Food: Dietary Concerns, Benefits, and Risks. Retrieved from [https://www.webmd.com/pets/dogs/features/raw-dog-food-dietary-concerns-benefits-and-risks]
R7: Raw Fed K9. (2025). Raw Fed vs. Kibble: A Comprehensive Comparison. Retrieved from [https://rawfedk9.com/blogs/news/raw-fed-vs-kibble-a-comprehensive-comparison]
R8: Oberbauer, A. M. (2019). A Review of the Impact of Neuter Status on Expression of Disease in Dogs. Frontiers in Veterinary Science.
R9: Centers for Disease Control and Prevention (CDC). (2023). Salmonella and Dogs. Retrieved from [https://www.cdc.gov/healthypets/pets/dogs.html]
R10: OMA’s Pride. (2024). The Truth About Raw Food Vs Kibble For Dogs. Retrieved from [https://omaspride.com/blogs/articles/comparing-raw-food-vs-kibble-for-dogs]
R11: Hill’s Pet Nutrition. (2023). Nutritionally Complete Dog Foods. Retrieved from [https://www.hillspet.com/dog-food/nutrition-tips/nutrition-basics]
R12: Association of American Feed Control Officials (AAFCO). (2022). Understanding Dog Food Labels.
R13: WebMD. (2024). Dog Food Allergies. Retrieved from [https://www.webmd.com/pets/dogs/dog-food-allergies]
R14: Pet Assure. (2024). Raw Food Diet for Dogs and Cats | Pros and Cons. Retrieved from [https://www.petassure.com/maxscorner/is-a-raw-diet-best-for-dog-and-cat-health/]
R15: Veterinary Partner. (2022). Diets for Dogs with Pancreatitis.
R16: American Veterinary Medical Association (AVMA). (2023). Nutrition for Puppies and Senior Dogs.
R17: PetMD. (2019). Transitioning Your Dog to a New Diet.
R18: National Research Council (NRC). (2006). Nutrient Requirements of Dogs and Cats. National Academies Press. Provides comprehensive guidelines on puppy nutrient needs for healthy growth.
R19: Hand, M. S., et al. (2010). Small Animal Clinical Nutrition (5th ed.). Mark Morris Institute. Discusses diet transition strategies for puppies and adult dogs.
R20: Case, L. P., et al. (2011). Canine and Feline Nutrition: A Resource for Companion Animal Professionals (3rd ed.). Elsevier. Covers bone and mineral requirements for growing dogs and risks of over-supplementation.
R21: This Dog’s Life. (n.d.). Here’s what is in dog food that causes allergies. Retrieved from https://thisdogslife.co
R22: European Food Safety Authority. (n.d.). Scientific opinions on various food and feed additives. Retrieved from https://efsa.europa.eu
R23: Pet Food Institute. (n.d.). Understanding pet food ingredients. Retrieved from https://petfoodinstitute.org
R24: Freeman, L. M. (2018). It’s not just grain-free: An update on diet-associated dilated cardiomyopathy. Clinical Nutrition Service, Tufts University.
R25: Environmental Working Group. (n.d.). Guide to food additives. Retrieved from https://ewg.org
R26: Merck Veterinary Manual. (n.d.). Food toxicity and ingredient concerns in dogs. Retrieved from https://merckvetmanual.com
R27: Overall, K. L. (2013). Manual of clinical behavioural medicine for dogs and cats. Elsevier Health Sciences.
R28: Tran, Q. D., Hendriks, W. H., & van der Poel, A. F. B. (2008). Effects of extrusion processing on nutrients in dry pet food. Journal of the Science of Food and Agriculture, 88(9), 1487-1493.
R29: Smith, J., Brown, L., & Davis, M. (2020). The effects of high-heat processing on pet nutrition. Pet Health Publications.
R30: Lonsdale, T. (2001). Raw meaty bones: Promote health. Dogwise Publishing.
R31: Brown, K. (2009). The dog food detective: How to choose the best food for your pet. St. Martin’s Press.
R32: Verlinden, A., Hesta, M., Millet, S., & Janssens, G. P. J. (2006). Food allergy in dogs and cats: A review. Critical Reviews in Food Science and Nutrition, 46(3), 259–273. Overview of dietary elimination approaches for identifying food allergies in companion animals.
R33: Mueller, R. S., Olivry, T., & Prélaud, P. (2016). Critically appraised topic on adverse food reactions of companion animals (2): Common food allergen sources in dogs and cats. BMC Veterinary Research, 12(9). Discusses standard elimination trial durations and protocols.
R34: Olivry, T., & Mueller, R. S. (2017). Evidence-based veterinary dermatology: A systematic review of the pharmacotherapy of canine atopic dermatitis. Veterinary Dermatology, 28(1), 7-e2. Details timing and reintroduction strategies for identifying allergens.
R35: Jackson, H. A., & Hammerberg, B. (2002). Allergic skin diseases of dogs and cats. Clinical Techniques in Small Animal Practice, 17(3), 158–167. Explains identifying trigger ingredients during elimination trials.
R36: Dodds, W. J. (2017). Canine nutrigenomics: The new science of feeding your dog for optimum health. Dogwise Publishing. Provides guidance for maintaining balance while customizing diets based on tolerated ingredients.
R37: Billinghurst, I. (2016). Give Your Dog a Bone: The Practical Commonsense Way to Feed Dogs for a Long Healthy Life. Dogwise Publishing. Foundation text introducing raw feeding principles and weight-based portioning.
R38: Brown, S. (2010). Unlocking the Canine Ancestral Diet: Healthier Dog Food the ABC Way. Dogwise Publishing. Explains energy and growth-based feeding percentages for puppies and active dogs.
R39: Case, L. P., Daristotle, L., Hayek, M. G., & Raasch, M. F. (2011). Canine and Feline Nutrition: A Resource for Companion Animal Professionals (3rd ed.). Mosby Elsevier. Discusses caloric adjustments for aging and sedentary dogs.
R40: Freeman, L. M., & Heinze, C. R. (2012). Feeding dogs: Balancing diets and monitoring body condition. Journal of the American Veterinary Medical Association, 241(11), 1426–1433. Provides guidelines for evaluating body condition and adjusting feeding amounts.
R41: Knueven, D. R. (2018). The Holistic Guide for a Healthy Dog (5th ed.). Quarry Books. Outlines benefits of properly portioned raw diets on energy levels and body composition.
​
Photo By Moovet On Freeimages.com

By Norma Jeanne Laurette ​

​

• Introduction
• The Difference Between Sibling Rivalry & Alliance Aggression
  • Sibling Rivalry
  • Alliance Aggression
• Causes & Contributing Factors
• Canine Communication & Body Language
• Reading Behavioural Cues
• Commonly Observed Patterns
• Healing The Vagus Nerve For A Calmer Dog
• Understanding Sibling Rivalry
• Treatment For Sibling Rivalry
  • Eliminate The Possibility Of Physiological Or Pharmaceutical Contributors
  • Resource Control
  • Safety & Environmental Management
  • No Punishment Or Negativity
  • Identify The Triggers
  • Impulse Control Training
  • Desensitization & Counter Conditioning
  • Alternating Attention
  • Professional Guidance
• Understanding Alliance Aggression
• Causes & Contributing Factors
• Treatment For Alliance Rivalry
  • Eliminate The Possibility Of Physiological Or Pharmaceutical Contributors
  • Resource Control
  • Safety & Environmental Management
  • No Punishment Or Negativity
  • Identify The Triggers
  • Social Bond Management
  • Desensitization & Counter Conditioning
    • Dog/Dog Alliance
    • Dog/Human Alliance
  • Professional Guidance
  • Re-Homing One Dog
• Summary
• References

Sibling Rivalry

Sibling rivalry describes the tension and competition that can develop between dogs living in the same household, particularly those that grew up together or are littermates. Rivalry in dogs is typically driven by competition over resources such as food, toys, chew options, sleeping places, the guardian’s attention or for some dogs – a need to control all resources R3.

Alliance Aggression
​
Alliance aggression is more complicated than sibling rivalry because it’s caused by strong emotional bonds. As social animals, dogs form close relationships with those they trust, whether it’s another animal (usually another dog) or a person. These connections provide comfort and security, but if the bond becomes too intense or exclusive, it can lead to alliance aggression R46. This occurs when a dog behaves aggressively toward an animal or person it perceives to be a threat to its bonded companion R53.

Research has shown that wild dogs form alliances to help them survive, such as working together to hunt or defend the pack. In domestic dogs, this same behaviour can morph into alliance aggression R18 R19.

There are many factors that contribute to the development of aggression caused by rivalries and alliances.
​

1. Puppies raised in large litters often compete for their mother’s milk, warmth and attention, which can create early patterns of arousal and resource guarding R12. Without an early and thorough socialization and intervention, these tendencies can continue into adulthood R13.
2. Genetics can also play a role, as the health, temperament and behaviour of ancestors over four generations back can be passed on to the puppies, predisposing them to fearful, competitive, assertive or aggressive tendencies R14.
3. Limited resources, poor behaviour management and inconsistency on part of the guardian can all increase aggression.
4. Dogs that frequently win conflicts can learn that aggression works to get what they want, while those that never win can become fearful, anxious or defensive R15 R16.
5. Environmental stressors, medical issues and changes in the home can also trigger stress, anxiety and aggression R17.

​Understanding canine communication and body language is essential for successfully changing these unwanted behaviours. Dogs express their emotions in both obvious and subtle ways. Recognizing the early signs of tension, fear, stress and anxiety before they escalate into conflict is key to prevention and effective intervention. For more information about subtle canine communications, see my article entitled Micro-Expressions in Dogs.

​With sibling rivalry aggression, tension often develops around toys, chew options, sleeping places, during feeding times and/or interactions with the guardian. Early signs that can lead to conflict include displacement behaviours such as yawning or lip licking, blocking movements, hard stares and stiff body postures.

​With alliance aggression, the targeted dog can consistently show signs of avoidance or fear R20. In severe cases, a dog may be repeatedly pushed out of the social group or attacked R21.

​Commonly Observed PatternsWith alliance aggression, a dog can also team up to protect its guardian. The behaviour often escalates not only because it’s self-rewarding but also because the guardian rewards the behaviour by comforting, stroking or praising the dogs afterward R27.

Dogs that are sick or in pain can sometimes be targeted or avoided by others, which is a natural instinct from their wild ancestors that sometimes push weak, sick or injured pack members away to keep the pack safe and conserve resources R54 R55.

​When any behaviour problem is exacerbated by tension, stress or anxiety, nervous system health becomes important R56 R57. Promoting a healthy vagus nerve in dogs involves supporting both their physical and emotional wellbeing. Healing and supporting the vagus nerve can play a major role in rehabilitating dogs suffering from unpleasant emotions that trigger aggression R56 R57.

The vagus nerve is the body’s main regulator of the parasympathetic nervous system, which reduces stress R58. When the vagus nerve is functioning well, it helps lower heart rate, reduce inflammation and calm high states of arousal in the brain and body R58 R59. Because unpleasant emotions can be caused by an imbalance in the nervous system, supporting a healthy vagus nerve can help restore balance, allowing dogs to shift from a chronic fight-or-flight state to a calmer, more stable emotional state R60. This shift helps provide a foundation for healthier behavioural responses R61.

Gentle, positive interactions such as calm stroking, light massage and fun play help build trust and promote relaxation in dogs, while consistent daily routines provide a sense of security and reduce stress R60 R62. Regular exercise combined with canine enrichment activities and positive training supports a balanced nervous system and overall emotional wellbeing R63 R29. Additional strategies including canine massage, acupressure and safe chew options offer further opportunities to soothe and calm the dog. Time spent in peaceful, natural outdoor environments, especially where dogs can sniff and explore, has proven to lower stress hormone levels R67. Supporting gut health through a high-quality, natural diet strengthens the connection between the gut and the nervous system R65 R66. Together, these approaches nurture vagal tone and overall resilience in dogs R60 R64. For more information about canine enrichment see my article entitled Canine Enrichment For Dogs.

By supporting a healthy vagus nerve, a dog’s nervous system will be better equipped to control its emotions and impulses R56 R61. Strengthening the vagus nerve doesn’t replace behaviour modification but instead complements it by creating the physiological conditions required for healing and rehabilitation R60 R63. For more information about the vagus nerve see my article entitled Healing The Vagus Nerve For A Calmer Dog.

​Sibling rivalry aggression in dogs occurs when two or more dogs from the same household, often littermates or dogs of similar age and temperament, compete for resources or attention from their guardian R68. This form of aggression can develop gradually as the dogs mature and begin asserting themselves and testing boundaries within the household R69. Common triggers include competition over food, toys, chew options, sleeping places or attention R70.

A guardian can unintentionally reward sibling rivalry aggression when the competition is for their attention, by responding in a manner that reinforces one dog’s behaviour over the other. For example, if two dogs are demanding attention and the guardian strokes or speaks to the more assertive dog to calm the situation, that dog learns that demanding and aggressive behaviour works to get positive attention R73. Comforting the nervous dog during the conflict can unintentionally teach the dog that its behaviour is also an effective way to get protection and attention R74. Even scolding or physical intervention can be perceived by the dogs as attention, unintentionally reinforcing the behaviour.

​
​Eliminate The Possibility Of Physiological Or Pharmaceutical ContributorsWhen dealing with any type of aggression it’s always important to eliminate the possibility of physiological or pharmaceutical contributors first, because all the behaviour modification in the world won’t change behaviour with a physical cause. For this reason, a visit to the veterinarian should always be your first priority R36 R37. For more information see my article entitled Canine Aggression – Physiological & Pharmaceutical Causes.

Resource Control

Our foundation for teaching new behaviours or changing any unwanted behaviour is resource control. The two rules of resource control are:
​

1. Ignore all inappropriate demands. Instead, look for opportunities to give the dog love, attention and other valued resources when not demanding them, when demonstrating acceptable independent behaviour, offering desired behaviours or correct responses to instructions.

1. Require the dog to earn everything it values by first offering an acceptable behaviour such as sit or down. With repetition the dog begins to default to desirable behaviours without being asked.

Safety & Environmental Management

Keep daily routines calm and consistent. Feed the dogs in separate areas and remove any resources they might fight over when together R29. Use barriers such as gates or exercise pens to allow visual contact while preventing physical conflict. If aggression occurs at the barrier, add another to increase the distance between them and when supervision isn’t possible, keep the dogs on opposite sides of the barrier. When the dogs are together, provide multiple resting spots, water bowls and low-value toys to minimize competition R31. If a specific bed, bowl, toy or chew option triggers conflict, temporarily remove it.

No Punishment Or Negativity

​Always avoid reprimands, punishment or any form of negativity, as these increase the fear, stress and anxiety that are at the root of aggressive behaviour. Research has shown that negativity leads to emotional distress, which inhibits one’s ability to think, learn, remember, solve problems and make choices. Not only is negativity of any kind counterproductive to the learning process, unpleasant emotions also compromise a dog’s temperament and emotional wellbeing. Instead of reprimands or punishments, focus on setting the dogs up for success and rewarding calm, desirable behaviour.

Identify The Triggers

Identify the triggers such as competition for attention, toys, chew options, food, treats or sleeping place. Observe which dog initiates the behaviour and under what circumstance it occurs. Use environmental management to avoid the triggers until they are part of the rehabilitation process R27.

Impulse Control TrainingIn order to nurture self-control, work with one dog at a time and teach the cues wait, sit stay, down stay, leave it, watch me and go to your mat or bed. Feel free to contact me for instructions for each of these cues.
​
Desensitization & Counter Conditioning

When both dogs are relaxed, gradually reintroduce shared activities in a controlled manner. Start with parallel walks and slowly decrease the distance between them as long as they remain calm R33. You can also practice training exercises side-by-side, beginning with plenty of space between them and reducing it gradually as they maintain their composure. Always reward both dogs equally to prevent competition. If you notice any signs of tension or stress during walks or training, increase the distance until they’re calm, then once again, slowly close the gap. Use treats and praise to build positive associations with each other’s presence.

Alternating Attention

Take turns offering privileges such as your attention, greeting guests or playing with you. Begin with the dogs on opposite sides of a barrier. Watch closely for any signs of stress that could escalate and don’t remove the barrier until both dogs remain relaxed throughout the process in close proximity. When interacting without the barrier, step in immediately but calmly with separation and redirection if the dog not receiving attention shows any signs of stress R34 R35. If regression occurs, return to your last point of success and proceed slowly from there.

Professional GuidanceGuidance from a qualified and experienced, positive behaviour expert can prove invaluable to help identify all contributing factors and create an effective and safe rehabilitation program.

​In homes with more than one dog, alliance aggression can occur when two dogs team up against another, sometimes one from outside the home. When both dogs become excited, they feed off each other’s emotions and energy, and the situation can quickly escalate out of control R47.

In dog-human alliances similar patterns can occur. A dog that’s very attached to one person can become protective or possessive, trying to block other dogs or people from approaching or growling or biting when they get too close R48. These reactions are often rooted in insecurity, anxiety or a desire to keep the social group calm and stable.

Understanding alliance aggression as a misdirected social and emotional response rather than disobedience is important when determining the best way to proceed, which is by building confidence, promoting independence and rewarding calm behaviour in social settings R49.

​There are several factors that contribute to alliance aggression.

1. Social bonds play an important role as dogs can feel the need to defend close relationships through aggression toward perceived outsiders R43.
2. Resource guarding can also be a factor since some dogs view their allies as valuable social and emotional resources, and can react aggressively if that bond feels threatened R44.
3. Territorial behaviour can increase alliance aggression, especially when someone enters the dog’s space or interacts with its bonded companion within its territory R45.
4. Low confidence or fear can trigger alliance aggression in anxious or insecure dogs, when they behave defensively to preserve their sense of safety and stability within their social group R46.
5. When a nervous or insecure dog behaves aggressively toward another dog to gain its guardian’s attention and the guardian comforts the nervous dog, this can unintentionally reward the aggression. If the guardian protects the insecure dog, the dog can learn that aggression is a good way to get attention and feel safe R50. Over time, the dog may start feeling confident only when the guardian is nearby, even though it remains insecure in other situations. As this pattern continues, the dog can become possessive and protective of the guardian R51.

​Eliminate The Possibility Of Physiological Or Pharmaceutical ContributorsAs previously stated, when dealing with any type of aggression it’s always important to eliminate the possibility of physiological or pharmaceutical contributors first, because all the behaviour modification in the world won’t change behaviour with a physical cause. For this reason, a visit to the veterinarian should always be your first priority R36 R37. For more information see my article entitled Canine Aggression – Physiological & Pharmaceutical Causes.

Resource Control

​As previously mentioned, resource control is the foundation of any training or behaviour modification program. For more information about resource control see our first book Blueprint To A Happy Dog R76.

Safety & Environmental Management

Alliance aggression can be more dangerous than sibling rivalry aggression because it’s fuelled by stronger emotions, can escalate with group energy, have multiple targets instead of one, be influenced by unpredictable human behaviour and is self-rewarding.

Your first priority will be to immediately separate the bonded pair from the victim to prevent further aggressive episodes. If the aggressor is already bullying or attacking the victim, use barriers to prevent escalation and keep the intended victim safe. Avoid confrontations by distracting and re-directing the dogs to safely break up group arousal before it escalates R29 R34.

No Punishment Or Negativity

As previously mentioned, negativity of any kind causes unpleasant emotions that can lead to aggression, it’s counter productive to the learning process and compromises the dog’s temperament and emotional wellbeing. Instead, focus on setting the dogs up for success and rewarding calm, desirable behaviour.

Identify The Triggers

Identify the triggers, such as increased arousal, competition for a resource, defence of territory or a dog defending its bonded companion from a perceived threat. Observe which dog initiates the behaviour and under what circumstances it occurs. Be careful to not reward protective or jealous behaviour, as doing so can reinforce the aggression and escalate future conflicts R27. Use environmental management to avoid the triggers until they are part of the rehabilitation process R27.

Social Bond Management

Help each bonded dog develop its own relationship with its guardian by taking separate walks, conducting individual training and play sessions and feeding them separately R35. Teach the same cues as those used for sibling rivalry aggression to promote impulse control. Wait to reintroduce group play until each dog responds reliably to training and demonstrates excellent self-control.

Desensitization & Counter Conditioning

Dog/Dog AllianceTreatment begins with preventing situations where the alliance is triggered until stability is restored. Each dog should be trained separately using positive methods to build focus, calmness and confidence away from each other. Structured individual walks and training sessions strengthen each dog’s bond with the guardian instead of with each other.

Gradual reintroductions start with parallel walks and progress to calm, controlled interactions without a target present. Then do the same thing with the target at a distance to help desensitize both dogs to the presence of the former target. During these exercises, all reinforcement should come from the handler, not the environment or the other dog. Over time, the goal is to replace alliance-based behaviour with cooperative calmness directed by the guardian.

Dog/Human Alliance

When the alliance is between a dog and a human, the dog perceives the human as part of its team against another dog or person. This behaviour can be caused by protective instincts, over-attachment or unintentional reinforcement by the human.

The first step is strict management to prevent situations that trigger the dog’s defensive alliance, such as allowing the dog to position itself between the human and another dog or person, or having the human confront or interact tensely with the target. The human should remain calm and neutral during all interactions, avoiding protective or reassuring behaviour that could reinforce the aggression. The dog should be rewarded only for calmly disengaging and for reliably following instructions in the presence of the target.

If the aggression is directed toward another dog, both the favoured human and the target dog should be involved in gradual desensitization sessions. The human reinforces calm, neutral behaviour when the target dog is present while ignoring and tension or staring. Always start at a distance that doesn’t illicit unwanted behaviour and slowly decrease the distance, as the dog remains calm. Controlling the distance along with gradual desensitization will build tolerance without feeding into the alliance dynamic.

If the alliance is directed toward another person, the same principles apply, but with both people actively participating. The target person can become associated with positive association by tossing treats, toys or offering calm attention from a safe distance, while the favoured human maintains relaxed and neutral body language, while reinforcing calm behaviour from the dog. With repetition, the dog will learn that there is no threat and that this person means good things happen for the dog. This will change its motivation from “I want it to go away” to “I want it”. For more information about motivations see our first book Blueprint To A Happy Dog R76.

In all forms of alliance aggression, negativity or reprimands of any kind, or emotional reactions will escalate the problem by increasing the sense of threat. Success is only achieved with non-reactive handling, consistency and rewarding independent behaviour. The goal is to diffuse the unhealthy alliance, rebuild trust with everyone involved, and nurture a balanced social environment where the dog’s loyalty is bases on trust instead of defensiveness.

Professional Guidance

Again, guidance from a qualified and experienced, positive behaviour expert can prove invaluable to help identify all contributing factors and create an effective and safe rehabilitation program.

Re-Homing One DogIf aggression persists in spite of consistent behaviour modification, re-homing one dog could be the most humane solution as ongoing fear, stress or anxiety negatively affects a dog’s temperament, health and emotional wellbeing. If re-homing the aggressor, the dog must become an only dog and the new guardian must be informed of the issue to prevent making bad choices moving forward.

Euthanasia should be considered as a last resort and only if there is risk of injury that can’t be predicted or prevented after every humane option has been exhausted R38 R39.

​R1: Horwitz, D. F., & Landsberg, G. (2018). Behavior problems of dogs. Elsevier. Comprehensive overview of aggression origins.
R2: Overall, K. L. (2013). Manual of clinical behavioral medicine for dogs and cats. Elsevier. Defines sibling rivalry patterns.
R3: Bradshaw, J. (2011). Dog sense: How the new science of dog behavior can make you a better friend to your pet. Basic Books. Discusses pack dynamics.
R4: McGreevy, P. (2017). A modern dog’s life. UNSW Press. Links upbringing and rivalry.
R5: Beaver, B. V. (2009). Canine behavior: Insights and answers. Elsevier. Discusses age and competition.
R6: Mech, L. D. (2019). Alpha status, dominance, and division of labor in wolf packs. Canadian Journal of Zoology, 77(8), 1196–1203.
R7: Case, L. P. (2013). The dog: Its behavior, nutrition, and health. Wiley. Discusses environmental triggers.
R8: Houpt, K. A. (2018). Domestic animal behavior for veterinarians and animal scientists. Wiley. Hormonal influences on behavior.
R9: Herron, M. E., Shofer, F. S., & Reisner, I. R. (2009). Survey of the use and outcome of confrontational and non-confrontational training methods in client-owned dogs. Applied Animal Behaviour Science, 117(1-2), 47–54.
R10: Miklósi, Á. (2015). Dog behaviour, evolution, and cognition. Oxford University Press. Alliance behavior in social species.
R11: Range, F., & Virányi, Z. (2015). Social learning from humans and conspecifics in dogs. Frontiers in Psychology, 6, 1–9.
R12: de Waal, F. (2016). Are we smart enough to know how smart animals are? W.W. Norton. Coalition behaviors.
R13: Schilder, M. B., et al. (2014). Influence of emotional contagion in domestic dogs. Behavioural Processes, 110, 25–30.
R14: Horwitz, D. F. (2020). Canine aggression: Diagnosis and treatment. Elsevier.
R15: Yin, S. (2009). Low stress handling, restraint and behavior modification of dogs & cats. CattleDog Publishing.
R16:  Lindsay, S. R. (2014). Handbook of applied dog behavior and training, Vol. 3. Wiley.
R17: Dodman, N. (2016). Pets on the couch. Atria Books.
R18: Bamberger, M., & Houpt, K. (2006). Signalment factors, comorbidity, and trends in behavior diagnoses in dogs. Journal of the American Veterinary Medical Association, 229(10), 1591–1601.
R19: Sherman, B. L., & Mills, D. S. (2008). Canine aggression: A guide for professionals. Blackwell.
R20: O’Heare, J. (2014). Aggressive behavior in dogs: A comprehensive technical manual for professionals. DogPsych Publishing.
R21: Bradshaw, J. W. S., Blackwell, E. J., & Casey, R. A. (2009). Dominance in domestic dogs—useful construct or bad habit? Journal of Veterinary Behavior, 4(3), 135–144.
R22: Hiby, E. F., Rooney, N. J., & Bradshaw, J. W. S. (2004). Dog training methods: Their use, effectiveness, and interaction with behavior and welfare. Animal Welfare, 13(1), 63–69.
R23: Beerda, B., et al. (1998). Chronic stress in dogs subjected to social and spatial restriction. Physiology & Behavior, 66(2), 243–254.
R24: Serpell, J. (2016). The domestic dog: Its evolution, behavior and interactions with people. Cambridge University Press.
R25: McConnell, P. B. (2002). The other end of the leash. Ballantine Books.
R26: Hiby, E. F., & Rooney, N. J. (2011). Positive reinforcement and guardian consistency improve behavior. Animal Welfare, 20(3), 309–316.
R27: Reid, P. J. (2012). Learning in dogs. Applied Animal Behaviour Science, 138(1–2), 1–13.
R28: Donaldson, J. (2010). Culture clash. James & Kenneth Publishers.
R29: Shepherd, K. (2017). Behavioural medicine in dogs and cats. CRC Press.
R30: Yin, S. (2011). Perfect puppy in 7 days. CattleDog Publishing.
R31: Dunbar, I. (2004). Before and after getting your puppy. New World Library.
R32: Blackwell, E. J., & Casey, R. A. (2006). The use of veterinary behaviorists in companion animal practice. Journal of Veterinary Behavior, 1(3), 94–101.
R33: Horwitz, D. F., & Landsberg, G. M. (2016). Diagnosis and management of canine aggression. Elsevier.
R34: Yin, S. (2013). Dog behavior: Understanding and preventing problems. CattleDog Publishing.
R35: YMcConnell, P. B. (2013). For the love of a dog. Ballantine Books.
R36: Reid, P. J. (2009). Learning theory and behavior modification in companion animals. Wiley.
R37:  Hetts, S., et al. (2004). Group housing and behavior management in multiple-dog households. Applied Animal Behaviour Science, 87(1–2), 1–12.
R38: Rooney, N. J., & Cowan, S. (2011). Training methods and guardian–dog interactions: Links with dog behavior and welfare. Animal Welfare, 20(3), 309–316.
R39: Fatjó, J., & Bowen, J. (2020). The welfare implications of behavioral disorders in dogs. Journal of Veterinary Behavior, 35, 1–10.
R40: Rooney, N. J., & Cowan, S. (2011). Training methods and guardian–dog interactions: Links with dog behavior and welfare. Animal Welfare, 20(3), 309–316.
R41: Horwitz, D. F., & Mills, D. S. (2020). BSAVA Manual of Canine and Feline Behavioural Medicine (3rd ed.). British Small Animal Veterinary Association. Overview of behavioural motivations and social influences in canine aggression.
R42: Bradshaw, J. W. S. (2011). Dog Sense: How the New Science of Dog Behavior Can Make You a Better Friend to Your Pet. Basic Books. Explains canine social structures and their role in behaviour.
R43: Casey, R. A., & Westgarth, C. (2021). Dog Bites: A Multidisciplinary Perspective. 5M Publishing. Discusses resource-related aggression and social attachment dynamics.
R44: Beaver, B. V. (2009). Canine Behavior: Insights and Answers (2nd ed.). Saunders Elsevier. Covers territorial and defensive aggression patterns in dogs.
R45: Overall, K. L. (2013). Manual of Clinical Behavioral Medicine for Dogs and Cats. Elsevier. Details anxiety-related aggression and social insecurity responses.
R46: Bradshaw, J. (2011). Dog Sense: How the New Science of Dog Behavior Can Make You a Better Friend to Your Pet. Basic Books. Explains social bonding and cooperation in dogs as adaptive survival traits.
R47: Horwitz, D. F., & Mills, D. S. (2020). BSAVA Manual of Canine and Feline Behavioural Medicine (3rd ed.). British Small Animal Veterinary Association. Discusses group aggression, social facilitation, and cooperative behaviours in dogs.
R48: Overall, K. L. (2013). Manual of Clinical Behavioral Medicine for Dogs and Cats. Elsevier. Details attachment-based aggression and emotional dependency in canine–human relationships.
R49: McConnell, P. B. (2002). The Other End of the Leash: Why We Do What We Do Around Dogs. Ballantine Books. Describes how human interactions shape canine behaviour and how to build balanced, secure attachments.
R50: Horwitz, D. F., & Mills, D. S. (2020). BSAVA Manual of Canine and Feline Behavioural Medicine (3rd ed.). British Small Animal Veterinary Association. Discusses reinforcement of aggressive behaviours through guardian responses.
R51: Overall, K. L. (2013). Manual of Clinical Behavioral Medicine for Dogs and Cats. Elsevier. Explains the role of guardian behaviour in shaping inter-dog dynamics and alliance aggression.
R52: Donaldson, J. (2017). Train Your Dog Like a Pro. Howell Book House. Describes management and reinforcement strategies to reduce competitive or possessive behaviour between dogs.
R53: Borchelt, P. L., & Voith, V. L. (1982). Aggressive behavior in dogs and cats. The Veterinary Clinics of North America: Small Animal Practice, 12(4), 653–662. A foundational paper describing types of canine aggression, including protective and alliance-based aggression associated with bonded individuals.
R54: Landsberg, G., Hunthausen, W., & Ackerman, L. (2013). Behavior Problems of the Dog and Cat (3rd ed.). Saunders. Overview of behaviour patterns linked to medical and social stressors in dogs.
R55: Mech, L. D., & Boitani, L. (2003). Wolves: Behavior, Ecology, and Conservation. University of Chicago Press. Discusses how wild canids may exclude or drive away weak or ill pack members to preserve group stability and resources.
R56: Porges, S. W. (2011). The polyvagal theory: Neurophysiological foundations of emotions, attachment, communication, and self-regulation. W. W. Norton & Company. Explains the role of the vagus nerve in emotional regulation and behaviour.
R57: Dodman, N. H. (2010). Dogs with aggression: Understanding and treating rage syndrome and idiopathic aggression. Animal Behaviour Clinic Publications. Discusses neurological and physiological contributors to canine aggression.
R58: Breit, S., Kupferberg, A., Rogler, G., & Hasler, G. (2018). Vagus nerve as modulator of the brain–gut axis in psychiatric and inflammatory disorders. Frontiers in Psychiatry, 9, 44. Examines parasympathetic nervous system regulation and vagus nerve function.
R59: Thayer, J. F., & Sternberg, E. (2006). Beyond heart rate variability: Vagal regulation of allostatic systems. Annals of the New York Academy of Sciences, 1088(1), 361–372. Describes vagus nerve influence on heart rate and inflammation.
R60: Levine, G. N., et al. (2017). Lifestyle management of the vagus nerve and stress: Implications for mental and physical health. Journal of the American College of Cardiology, 69(20), 2477–2486. Discusses lifestyle strategies to enhance vagal tone and stress resilience.
R61: Case, L. P., et al. (2016). Canine and feline behaviour for veterinary technicians and nurses (2nd ed.). Wiley-Blackwell. Covers behavioural management and the importance of nervous system balance in reducing aggression.
R62: Horowitz, A. (2009). Inside of a dog: What dogs see, smell, and know. Scribner. Explains how social interactions and routines influence canine stress.
R63: McGreevy, P., & Nicol, C. (2010). The playful dog: Exercise, enrichment, and training for behaviour management. Trafalgar Square Publishing. Discusses exercise, enrichment, and positive reinforcement in supporting nervous system balance.
R64: Rooney, N. J., & Cowan, S. (2011). Training methods and owner–dog interactions: Links to behaviour and welfare. Journal of Veterinary Behaviour, 6(5), 213–220. Examines enrichment and training effects on canine stress regulation.
R65: Bravo, J. A., et al. (2011). Ingestion of Lactobacillus strain regulates emotional behaviour and central GABA receptor expression in a mouse via the vagus nerve. Proceedings of the National Academy of Sciences, 108(38), 16050–16055. Demonstrates diet influence on vagal function and stress.
R66: Wells, D. L. (2009). The effects of natural environments on the behaviour and welfare of animals. Journal of Environmental Psychology, 29(4), 429–438. Highlights the calming effects of outdoor natural environments on stress.
R67: D’Aniello, B., Semin, G. R., Alterisio, A., Aria, M., & Scandurra, A. (2018). Interspecies transmission of emotional information via chemosignals: From humans to dogs (Canis lupus familiaris). Animal Cognition, 21(1), 67–78. https://doi.org/10.1007/s10071-017-1139-x — Demonstrates that dogs detect human emotional states through chemosignals in breath and sweat.
R68: Landsberg, G., Hunthausen, W., & Ackerman, L. (2013). Behavior Problems of the Dog and Cat (3rd ed.). Saunders Elsevier. Comprehensive overview of canine behavioural issues, including intra-household aggression.
R69: Overall, K. L. (2013). Manual of Clinical Behavioral Medicine for Dogs and Cats. Elsevier. Detailed guide on behavioural development and social hierarchy in dogs.
R70: Beaver, B. V. (2009). Canine Behavior: Insights and Answers (2nd ed.). Saunders Elsevier. Explains competition and resource-related aggression in multi-dog households.
R71: Horwitz, D. F., & Mills, D. S. (Eds.). (2020). BSAVA Manual of Canine and Feline Behavioural Medicine (3rd ed.). British Small Animal Veterinary Association. Provides clinical signs and management strategies for aggression.
R72: Yin, S. (2009). Low Stress Handling, Restraint and Behavior Modification of Dogs & Cats. CattleDog Publishing. Focuses on prevention and management techniques to reduce inter-dog conflict and promote harmony.
R73: McConnell, P. B. (2002). The Other End of the Leash: Why We Do What We Do Around Dogs. Ballantine Books. Discusses how human responses can unintentionally reinforce undesirable canine behaviours.
R74: Donaldson, J. (1996). The Culture Clash. James & Kenneth Publishers. Explores the effects of human emotional reactions on canine learning and reinforcement patterns.
R75: Pryor, K. (2006). Reaching the Animal Mind: Clicker Training and What It Teaches Us About All Animals. Scribner. Details how timing and reinforcement influence behaviour and how to reward calmness effectively.
R76: Laurette. NJ. & Ceci.Greg. Blueprint To A Happy Dog. (2019). Canine Communication Styles. https://dogtrainingcareers.com/product/blueprint-to-a-happy-dog/
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Image by Rolf Dobberstein from Pixabay