We often think of dog food as simply fuel, something to keep our pets going day to day. But just like in humans, diet plays a significant role in shaping mood, energy, focus and even behaviour. If your dog seems hyperactive, lethargic, anxious or unusually irritable, the food in their bowl could be part of the problem.
In this article, we’ll explore the connection between diet and behaviour, looking at what might cause changes in your dog’s mood or response to training, and how you can make better choices to support their emotional wellbeing.
The Brain Gut Connection in Dogs
The gut and brain are closely linked through a system often called the gut brain axis. This connection means that what your dog eats doesn’t just affect their digestion, it can influence their mood, emotional stability and even ability to learn.
An unbalanced or poor quality diet can disrupt this balance, causing symptoms that go far beyond the stomach. Just like a child loaded up on sugar may bounce off the walls, a dog fed inconsistent or unsuitable food may struggle to regulate their energy and behaviour.
Signs Your Dog’s Behaviour May Be Affected by Diet
While every dog is different, the following behavioural signs can be influenced by diet:
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Sudden hyperactivity or restlessness
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Difficulty focusing during training
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Food guarding or aggressive behaviour around meals
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Lethargy, depression or withdrawal
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Excessive chewing or licking
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Poor sleep or night time restlessness
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Heightened anxiety or reactivity
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Increased barking or sensitivity to sounds
Of course, many of these symptoms can have multiple causes, including health problems or lack of training. But if your dog is showing behavioural changes with no obvious trigger, it’s worth looking at their diet more closely.
Common Dietary Causes of Behavioural Issues
Let’s take a look at how specific elements of your dog’s diet can influence behaviour:
1. Low Quality Ingredients
Cheaper dog foods often contain low grade fillers, artificial colours, preservatives and vague meat by products. These may keep your dog full, but they offer little nutritional value. In some cases, additives may even trigger behavioural changes, especially in dogs sensitive to synthetic ingredients.
Watch out for artificial colours (like E numbers in human food), preservatives such as BHA or BHT, and vague terms like “animal derivatives” instead of named meats.
2. Protein Imbalance
Dogs need protein for muscle growth, energy and brain function. However, too much protein, especially from poor quality sources, can contribute to hyperactivity, particularly in younger dogs. On the flip side, too little protein can lead to low energy, poor concentration, and sluggishness.
Dogs who are working, training or recovering from illness may need more protein than an average pet. But it’s about balance, and getting it from the right sources like chicken, turkey, salmon or lamb.
3. Sudden Dietary Changes
If you’ve changed your dog’s food recently and noticed a behavioural shift, it could be due to the transition. Dogs thrive on routine, and sudden changes to their food can cause stomach upset, discomfort or increased stress. Always transition gradually over a week or more.
4. Food Sensitivities and Allergies
Some dogs react to common food ingredients like beef, wheat, dairy, eggs or soy. These reactions may show up as itchy skin or loose stools, but they can also cause discomfort that affects mood.
A dog in pain or discomfort may appear more irritable, withdrawn or reactive. If you suspect an allergy or intolerance, your vet may suggest an elimination diet to identify the trigger.
5. Blood Sugar Swings
Just like humans, dogs can experience dips and spikes in blood sugar based on what and when they eat. High carbohydrate diets or treats loaded with sugar (yes, even in dog food) can lead to mood fluctuations, restlessness or even anxious behaviour.
Feeding consistent, balanced meals at the same time each day helps keep your dog’s blood sugar stable, which can support more consistent behaviour.
Behaviour and Nutrients: What to Look For
To support calm, stable behaviour, it’s important to make sure your dog’s food includes the right nutrients. Here are some key ones to look out for:
1. Omega 3 Fatty Acids
Found in fish oil and flaxseed, omega 3s support brain function, reduce inflammation and have been shown to improve attention and reduce anxiety in some dogs. They’re particularly beneficial for puppies, seniors and dogs in training.
2. B Vitamins
These help with energy regulation, brain development and mood stability. A lack of B vitamins may result in irritability or lack of focus. Whole foods like liver, eggs, and green vegetables provide these naturally.
3. Tryptophan
An amino acid found in turkey, chicken and eggs, tryptophan is a precursor to serotonin, the “feel good” hormone. Diets rich in tryptophan have been linked to reduced aggression and better emotional regulation in dogs.
4. Complex Carbohydrates
Whole grains like brown rice or sweet potato release energy slowly, helping to maintain consistent energy throughout the day. This is in contrast to refined carbs like white rice or corn, which can cause rapid spikes and crashes.
Feeding Routines and Behaviour
It’s not just what your dog eats, it’s also when and how they eat.
1. Establish Regular Feeding Times
Dogs thrive on routine. Feeding at consistent times each day creates predictability, which helps reduce anxiety and supports stable blood sugar.
2. Avoid Free Feeding
Leaving food out all day may seem convenient, but it can reduce food motivation and blur the lines of structure. Mealtimes are a valuable opportunity to reinforce calm behaviour, focus, and training routines.
3. Use Mealtimes for Mental Stimulation
Feeding from puzzle toys or scatter feeding can turn a routine task into an enriching experience. These practices help reduce boredom, slow down fast eaters, and encourage calm focus, all great for dogs that struggle with overstimulation.
When to Speak to a Vet or Behaviourist
If your dog’s behaviour seems to have changed suddenly or you suspect a link between their food and mood, don’t guess. Start by speaking to your vet. They can rule out underlying health issues or nutritional deficiencies.
In more complex cases, particularly involving aggression, fear or compulsive behaviour, a behaviourist may work alongside your vet to evaluate environmental and emotional factors, including diet.
Choosing the Right Food
There’s no one size fits all answer when it comes to dog food. Every dog has different needs based on age, breed, activity level, health history and sensitivities. However, the following general tips apply:
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Look for complete, balanced recipes with named ingredients
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Avoid foods with artificial colours, flavours or preservatives
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Choose high quality protein sources (e.g. chicken, salmon, duck)
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Consider grain free options only if your dog has a specific sensitivity
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Read labels carefully and research brands, don’t be swayed by marketing alone
If you’re unsure where to start, consult your vet or a qualified canine nutritionist. They can recommend a diet suited to your dog’s needs and behaviour goals.
Final Thoughts
Your dog’s behaviour is shaped by many factors, genetics, training, environment, health and yes, nutrition. Food is more than fuel. It’s a foundation for wellbeing.
By choosing high quality ingredients, maintaining a steady routine and watching how your dog responds to their diet, you can support not only their physical health but their emotional balance too. And if something feels off, don’t ignore it. A few changes to what’s in the bowl could make a world of difference.
