Could This Be the Reason Your Reactive Dog Is Still Struggling?

You’ve probably Googled things like:

“How can I stop my dog lunging at dogs on walks?” “Why is my dog reactive to everything?” “How do I calm my anxious dog?”

And many of the answer points to training, desensitisation, and management strategies.

But your dog’s behaviour isn’t only about training; what’s going on inside their body is just as important.

Yes, reactivity is a biological issue as much as a behavioural one. And nutrition plays a huge role in how your dog experiences stress, fear, and emotional balance.

What You’ll Learn in This Blog:

• How gut health directly influences reactivity and anxiety.
• How food affects dog behaviour—key nutrients that calm or intensify stress responses.
• The best diet for reactive dogs—what to feed, what to avoid, and how dog behaviour and nutrition go hand in hand.
• Supplements for reactive dogs—which nutrients help support calmness and emotional balance.

I’m Anna Bain, an accredited canine nutritionist and writer for ProDog Raw. My journey with Rudi opened my eyes to the complexities of reactive dogs and deepened my understanding of the power of nutrition in cultivating calm. Supporting him helped me lean into my knowledge of natural, real food and develop a more in-depth approach to how diet influences behaviour.

Dr. Katie Woodley is a holistic veterinarian with a clinical background in integrative medicine. She specialises in bridging the gap between conventional veterinary care and natural, nutrition-based healing through her website and online community at The Natural Pet Doctor.

Together, we’re here to give you the full picture—the science, the real-world understanding, and the practical steps to help your reactive dog feel calmer, happier, and more confident.

Living with a reactive dog is an emotional rollercoaster—frustrating, overwhelming, and exhausting.

Perhaps you’ve put in the work. You’ve studied behaviour techniques, followed training plans, and tried to desensitise your dog to their triggers. Yet the lunging, barking, and stress-filled reactions persist.

So what’s missing?

What if I told you that dog anxiety and diet are deeply connected? That your dog’s ability to stay calm and process stress isn’t just about training, lifestyle changes or how your respond to them, but also about their gut health and what’s in their bowl.

When I brought Rudi home, I knew rehoming a 13-month-old Northern Inuit wouldn’t be plain sailing. I expected challenges, but I didn’t expect just how much his reactivity would impact our lives.

The first few days? Seemed fine. But once he settled in, it was like a switch flipped. He became overstimulated and overwhelmed; his emotions took the wheel. His extreme reactivity bursting to the surface.

At the time, I had no clue what was really going on. All I knew was that I had a big dog with big reactions, and his behaviour felt chaotic, destructive, and completely out of control.

Walks felt unpredictable. He’d lunge at other dogs, certain people and bikes. His world felt overwhelming to him, and in turn, the situation became overwhelming for me.

At first, I did what most owners do. I threw myself into behaviour modification and training. I worked to build Rudi’s confidence, understand his triggers, and create a world where he felt safer. But it wasn’t just about his behaviour. I had to look at my own reactions too. How I responded to him at home and out in the world mattered just as much. Because it all links.

And while training was crucial, so was what was happening inside his body. That’s when I leaned into what I already knew: mood, behaviour, and diet are all connected. So, alongside training, I refined his nutrition, focused on balancing his gut health, and ensured he had the right calming diet to support his nervous system.

Let’s be clear—behaviour support and training are essential. If you’re struggling with a reactive dog, professional guidance to help manage escalations and implement behaviour strategies is crucial.

A dog constantly on edge, struggling with gut inflammation, blood sugar swings, or poor nutrient balance, is less able to stay calm, process stress, respond to training or develop a relaxed mindset.

When we take a holistic approach, addressing dog behaviour and nutrition together, we give our dogs the best possible chance at success. Because when we stop looking at behaviour in isolation and start supporting the whole dog, real change happens.

Reactivity isn’t just about the outward behaviour, whether that’s barking, lunging, freezing, all three, or something entirely different—it’s about how your dog processes the world. It’s easy to mistake it for aggression in some instances, but reactivity is usually driven by fear, frustration, or emotional overload.

Some dogs react because they’re scared, overstimulated, stuck in a habit, or simply haven’t learned how to cope with their environment – and that’s just a few of the possible reasons. While each dog’s triggers are unique, the root issue is often the same: they’re struggling to regulate their emotions.

Vet insights from Dr. Katie Woodley :

“Most people approach reactivity as purely a behavioural problem, but the reality is, it’s deeply tied to physiology and internal health. A dog’s ability to stay calm, process stress, and recover from triggers depends on a delicate balance of hormones, neurotransmitters, and nervous system regulation.

Reactive behaviours in dogs are often rooted in a complex interplay of physiological processes. At the core, stress and anxiety can trigger a cascade of hormonal and neurochemical changes in your dog’s body. Here are some key factors:

Adrenaline and cortisol overload – When a dog perceives a threat, their adrenal glands release adrenaline and cortisol, preparing the body for a fight-or-flight response. While essential for survival, chronic elevation of these stress hormones leads to heightened reactivity, anxiety, and difficulty calming down. This is why a calming diet for reactive dogs can be crucial in reducing stress responses.

Nervous system imbalance – The autonomic nervous system (ANS) controls involuntary bodily functions and is divided into the sympathetic (fight-or-flight) and parasympathetic (rest-and-digest) systems. Reactive dogs often have an overactive sympathetic response, making it hard to regulate their emotions once triggered.

Neurotransmitter imbalance – Chemicals like serotonin and dopamine play a crucial role in mood regulation and behaviour. If these neurotransmitters are out of balance, a dog may struggle with anxiety and heightened reactivity.[1]

Gut-brain axis disruptions – The gut and brain are closely linked through the gut-brain axis. Psychological stressors, poor diet, and environmental toxins can disrupt gut bacteria, affecting the production of neurotransmitters that support emotional stability. A key factor in managing dog behaviour and nutrition is supporting gut health through diet. [2,3]

Chronic inflammation – Inflammation, often caused by poor diet, stress, and environmental toxins, can affect brain function, making it harder for dogs to regulate emotions and leading to exaggerated reactivity. This highlights the importance of feeding the best diet for reactive dogs, as the right food choices can help combat inflammation and support emotional stability. [4] “

Understanding reactivity through a physiological lens changes how we approach it. Yes, training and behaviour support are essential—we need strategies to help our dogs navigate their triggers. But if their nervous system is in overdrive, their gut microbiome is imbalanced, and their stress hormones are running high, no amount of training alone will fix the issue.

This is why dog behaviour and nutrition must go hand in hand. By supporting your dog’s internal health, you can lower their baseline stress levels, making it easier for them to process the world and respond to training.

In the next section, we’ll dive deeper into gut health, how food affects dog behaviour, and why what’s in your dog’s bowl could be the key to helping them feel calmer and more in control.

How gut health influences your dog’s behaviour

Your dog’s brain and gut constantly talk to each other—like a 24/7 communication hotline between their stomach and emotions. This connection, known as the gut-brain axis, plays a massive role in your dog’s ability to stay calm, process stress, and regulate emotions.

Dr Katie Woodley explains…..

“The connection between your dog’s gut health and behaviour isn’t just anecdotal. It’s backed by science. The gut microbiome plays a crucial role in mood regulation, stress response, and emotional stability, and diet directly impacts this balance.

The gut does far more than digest food—it’s responsible for:

1. Influencing your dog’s immune system, inflammatory response, and endocrine system, all of which can affect behaviour.
2. Communicating with the nervous system to control stress responses.
3. Producing neurotransmitters like serotonin and dopamine, which regulate mood and emotional balance.

When the gut is out of balance (a state called dysbiosis), harmful bacteria outnumber beneficial bacteria, disrupting these processes and making it harder for dogs to handle stress.

Dysbiosis and neurotransmitter production – Beneficial bacteria in the gut help synthesize serotonin and dopamine, essential for mood regulation. When dysbiosis occurs, neurotransmitter production is disrupted, increasing anxiety and emotional instability [5]

Gut-brain communication disruptions – The gut and brain communicate via the vagus nerve and biochemical signaling pathways. A healthy gut microbiome supports clear messaging, while dysbiosis disrupts these signals, heightening stress and reactivity [6].

The role of fiber and prebiotics – The best diet for reactive dogs is rich in fiber and prebiotics that promote the growth of beneficial gut bacteria, helping to maintain a stable microbiome, optimal brain function, and a balanced stress response [2].

If your dog’s gut health is compromised, their ability to regulate emotions will be, too. This can lead to:

• More intense reactions to triggers
• Longer recovery from stress
• Increased anxiety and frustration

The good news? Gut balance can be restored. The right diet can support a healthier microbiome, regulate neurotransmitter production, and help your dog feel more resilient and in control.”

Dr Katie Woodley continues …..

“The food you feed your dog directly affects their behaviour, influencing everything from neurotransmitter production to stress hormone regulation. A poor diet can exacerbate reactivity by causing blood sugar spikes, chronic inflammation, and gut imbalances—all impacting mood and emotional stability.

Many commercial diets contain high levels of processed carbohydrates, inflammatory ingredients, and artificial additives, which can trigger hormonal imbalances, gut dysfunction, and neuroinflammation—leading to increased anxiety and heightened reactivity.

Carbohydrates & blood sugar spikes – Many kibble diets are packed with over 50% carbohydrates despite dogs having zero physiological need for them. These high-carb diets cause rapid blood sugar spikes, followed by crashes, resulting in mood swings, hyperactivity, and increased anxiety—similar to sugar highs in humans.

Nutrient depletion through processing – High-heat processing in kibble production destroys essential nutrients, including B vitamins, amino acids, and antioxidants, which are critical for brain function and stress regulation. Even if nutrients are added back in, their bioavailability is often reduced, meaning your dog may not absorb what they need for balanced moods.

Leaky gut & chronic inflammation – Processed diets often contain advanced glycation end products (AGEs), contributing to inflammation and increased intestinal permeability (leaky gut). This allows harmful substances to enter the bloodstream, triggering systemic inflammation that can affect brain function and behaviour.

Dysbiosis & gut-brain disruptions – Without enough fiber and prebiotics, beneficial gut bacteria struggle to thrive, leading to microbial imbalances (dysbiosis). A disrupted microbiome reduces serotonin and dopamine production, making it harder for dogs to regulate stress and emotions.

Cortisol & chronic stress – A poor diet can elevate cortisol, the body’s primary stress hormone. Chronically high cortisol levels are linked to increased anxiety, over-reactivity, and difficulty settling after triggers.

Insulin & blood sugar regulation – High-carb diets contribute to insulin resistance, which affects blood sugar control and worsens stress responses. Stable insulin levels are essential for maintaining a calm, balanced nervous system.

Adrenal health & stress resilience – The adrenal glands produce cortisol and adrenaline, both of which regulate stress. Nutrients like B vitamins, vitamin C, and omega-3 fatty acids support adrenal function, helping to modulate stress hormone production and improve emotional stability.”

A fresh, species-appropriate diet is key to emotional balance. Highly digestible, nutrient-dense ingredients, like those found in a raw dog food diet, support gut health [7], neurotransmitter production, and brain function—helping dogs handle stress better .

The best food for a reactive dog includes:

• Minimally processed, species-appropriate ingredients – Quality meat, organs, and bone for essential amino acids.
• Nutrient-dense vegetables & herbs – For antioxidants and gut support.
• Minimal or no grains, starches, or inflammatory fillers – To prevent gut dysbiosis and blood sugar fluctuations.
• Balanced Omega-3s – To reduce neuroinflammation and support brain function.

If you’re new to fresh, natural feeding our Raw Dog Food For Beginners and Top 12 Health Benefits of Raw Feeding Your Dog are great starting points to learn more.

The nutritional must-haves for reactive dogs—Dr. Katie Woodley breaks it down

“A nutrient-rich, anti-inflammatory diet supports brain health, nervous system function, and emotional stability. Certain nutrients directly reduce anxiety, stress, and reactivity by influencing neurotransmitter production, gut health, and inflammation levels.

1. Magnesium – essential for stress regulation

Magnesium is critical for nerve and muscle function and plays a role in psychological balance. A deficiency can lead to increased stress and anxiety.

🔹 Natural sources: Muscle meats, pumpkin seeds, spinach, chard.

2. L-Tryptophan – the precursor to serotonin

L-tryptophan is an essential amino acid that helps produce serotonin, a neurotransmitter influencing mood, sleep, and behaviour. Ensuring adequate levels can help reduce anxiety and promote calmness [8].

🔹 Natural sources: Turkey, chicken, eggs, salmon, and cod.

3. Omega-3 Fatty Acids – reducing neuroinflammation

Omega-3s, particularly EPA and DHA, are crucial in brain function and reducing inflammation. Chronic neuroinflammation can contribute to reactivity, anxiety, and aggression.

🔹 Natural sources: Fish oil (from sardines, salmon, mackerel), flaxseeds, chia seeds, and algae oil.

4. Tyrosine – reducing stress & supporting focus

Tyrosine is an essential amino acid involved in the production of dopamine and norepinephrine, both of which influence focus, mood, and stress resilience. It plays a role in reducing anxiety and supporting cognitive function.

🔹 Natural sources: Protein-rich foods such as animal meats.

6. Prebiotics – feeding beneficial gut bacteria

Prebiotics are non-digestible fibers that feed beneficial bacteria in the gut, supporting a healthy microbiome and neurotransmitter production.

🔹 Natural sources: Medicinal mushrooms, garlic, asparagus, bananas, chicory root, dandelion greens.

7. Probiotics – balancing the gut microbiome

Probiotics introduce live beneficial bacteria to help maintain gut health, which is crucial for digestion, immune function, and brain chemistry.

🔹 Natural sources: Fermented foods like kefir and yogurt, sauerkraut, and probiotic supplements with strains like Lactobacillus, Bifidobacterium, and Bacillus.

By eliminating processed, inflammatory foods and prioritizing fresh, nutrient-dense ingredients, we can provide the essential building blocks for a calmer, more resilient dog. Training becomes far more effective when diet supports gut health, brain chemistry, and stress regulation—giving reactive dogs the internal stability they need to thrive.”

We can’t talk about nutrition and reactivity without giving a nod to the king of calming—GABA (gamma-aminobutyric acid). This powerful neurotransmitter is like a natural chill pill for the brain, helping to slow things down, reduce overstimulation, and promote relaxation. When GABA levels are low, dogs can become more anxious, reactive and struggle to settle after stressful events.

While GABA itself isn’t something you can add to your dog’s bowl, the right species-appropriate diet provides all the building blocks needed to support natural GABA production. Key nutrients like L-glutamine, magnesium, and taurine, found in meat, organ meats, bone broth, and fermented foods, help keep GABA levels in check.

A healthy gut microbiome also plays a significant role since beneficial gut bacteria influence neurotransmitter balance, including GABA regulation.

While a minimally processed, natural diet, such as complete raw dog food, lays the foundation for emotional balance, targeted supplementation can provide extra support for reactive dogs—helping to strengthen the gut, regulate inflammation, and support the nervous system.

Dr Katie Woodley’s top picks :

“There’s no one-size-fits-all approach, but the following supplements and herbs have been shown to aid stress regulation and help reactive dogs feel more resilient.

Gut health & microbiome support

A healthy gut is the key to balanced behaviour, as it influences neurotransmitter production, inflammation control, and stress resilience. These supplements help restore gut balance and improve digestion:

Probiotics & Prebiotics — Promote a healthy microbiome, supporting the gut-brain axis and neurotransmitter production.

Colostrum – Contains growth factors and immunoglobulins that restore gut integrity and balance brain chemistry.

Bone Broth – Rich in collagen and amino acids, it helps repair the gut lining and regulate inflammation.

Slippery Elm – A natural gut soother, it calms the digestive system and supports nutrient absorption.

Anti-inflammatory support

Chronic inflammation, whether from diet, stress, or environmental factors, can heighten reactivity. These ingredients help lower inflammation and support brain function:

Omega-3 Fish Oil – EPA and DHA reduce neuroinflammation, supporting a calmer nervous system.

Turmeric (with Black Pepper) is a natural anti-inflammatory powerhouse that aids brain and gut health.

Medicinal Mushrooms – Such as reishi and lion’s mane, which support cognitive function and stress resilience.

Nervous system & stress regulation

These supplements help regulate the nervous system, making it easier for dogs to process stress and recover from triggers:

Chamomile – Known for its calming properties, chamomile can help ease anxiety and digestive discomfort.

Lemon Balm – Supports mood regulation and reduces nervous tension.

Ashwagandha – An adaptogen that helps lower cortisol levels and improves stress resilience. [9,10] Other adaptogens include: Astragalus, Ginseng, Reish mushrooms

Valerian – A natural sedative herb known to promote deep relaxation and reduce anxiety-related tension.

Rolled oats – A well-known nervine, oats help strengthen the nervous system, regulate stress responses, and promote emotional resilience.

These lists are not exhaustive, and each dog’s individual needs should be considered when choosing supplements.”

If you’d prefer expertly formulated blends specifically designed for dog health, ProDog’s range of dog supplements offer targeted support for gut health, stress relief, and overall well-being—key factors in helping reactive dogs thrive.

Colostrum is packed with immunoglobulins, growth factors, and peptides that restore gut balance, support brain chemistry, and regulate inflammation—key for cognitive function and emotional stability.

• Supports gut integrity and immune health
• Promotes neurotransmitter balance

For more on colostrum’s benefits, check out 10 Benefits of Colostrum Supplement for Dogs.

Digest

As gut health and reactivity are closely linked, ProDog’s Digest, gut health supplement for dogs, provides powerful whole-food ingredients that soothe and strengthen the digestive system.

🔹 Contains chamomile, slippery elm, aloe vera, and liquorice root to ease digestive discomfort.

🔹 Supports optimal gut microbiome function.

Check out our article, Dog Poo: Unveiling the Clues Into Canine Health, to see if your dog’s digestion needs extra support.

Boost

Packed with essential vitamins, minerals, antioxidants, and plant proteins, Boost, a multivitamin and mineral supplement for dogs, is designed to counteract oxidative stress, support immune health, and promote gut balance—key areas that affect reactivity and stress resilience.

🔹 Probiotics for microbiome support.

🔹 Antioxidants to combat oxidative stress from anxiety and overstimulation.

Muscle+

Many reactive dogs struggle with maintaining an ideal weight, and Muscle+, a weight gain supplement for dogs, provides targeted nutritional support for healthy weight gain and nervous system nourishment.

🔹 Contains fish collagen, omega-rich oils, and pumpkin seed powder to support gut and brain health.

🔹 Includes L-Taurine and L-Glutamine, amino acids that aid nervous system function and stress recovery.

🔹 Rolled oat powder helps soothe and balance the nervous system

For dogs that struggle with chronic stress, anxiety, or reactivity, supplementation can help bridge the gap between diet and behavioural support—providing the biochemical foundation needed for a calmer, more resilient dog.

If you’re new to dog supplements, ProDog’s Beginner’s Guide to Dog Supplements is the perfect starting point to learn more.

Living with a reactive dog can feel overwhelming, but when you take a step back and look at the bigger picture—beyond just training—you’ll see there are many other pieces to the puzzle that can make a difference.

There have been so many learning moments with Rudi. Some days, it’s smooth sailing; other days, it’s like living with an emotional tornado. But thanks to the right nutrition, a better understanding of his triggers, and guidance from professionals like Dr Katie Woodley, insightful trainers and behaviourist support, we now have far more smooth sailing days than choppy waters.

Remember, it’s not just about what’s happening inside your dog. It’s also about the energy you bring to the table. Dogs are incredibly intuitive; they pick up on our emotions more than we realise. When we’re calm and steady, our dogs feel safer. When we’re stressed or impatient, they absorb that too. Becoming aware of how your own mindset impacts your dog’s emotional state can make a world of difference in how they process stress.

By fuelling your dog’s body with the right nutrients, supporting their gut-brain connection, and being mindful of your own energy, you create an environment where they can feel calmer, safer, and more confident. Combine this with patience, training, understanding their innate needs, and relationship building, and you’ll start seeing real, lasting changes—both in them and yourself.

If you’re unsure where to start with your dog’s diet, ProDog’s expert nutrition team is here to help. We offer FREE tailored nutrition advice to support your dog’s health and behaviour. Contact us today to get expert recommendations for your dog’s specific needs.

For more in-depth guidance on holistic health, visit Dr Katie Woodley’s website, The Natural Pet Doctor, where she shares expert veterinary insights on supporting your dog naturally.