A Dog Nutritionist Explains How Diet Could Be Affecting Your Pet’s Anxiety, Energy, and Sleep.

• Can my dog’s diet really affect their anxiety levels or overall mood?
• What are the most common signs that a dog’s food isn’t meeting their nutritional needs?
• Are there specific ingredients or types of food that help calm anxious or hyperactive dogs?
• Some dogs sleep a lot, others struggle to settle—can what they eat during the day affect their sleep cycle?
• How much does sugar or carbohydrate content in dog food influence energy spikes or crashes?
• What’s your view on raw vs. commercial diets when it comes to supporting mental health and stable energy levels in dogs?
• What simple dietary changes can dog owners make today to support better behaviour, sleep, or emotional balance

Most pet owners understand that nutrition is key to their dog’s physical health. But what many don’t realise is that diet can also play a major role in a dog’s mood, behaviour and sleep patterns. We spoke to a pet nutrition expert Penny van der Merwe from Woofable to explore how what your dog eats might be influencing their mental and emotional well-being more than you think.

Can my dog’s diet really affect their anxiety levels or overall mood?

Absolutely. A dog’s diet has a direct impact on their anxiety and emotional state. What they consume influences brain chemistry, hormone levels, and gut health—all of which are tightly linked to behaviour. Deficiencies in nutrients like omega-3 fatty acids, magnesium and vitamin B can increase stress and agitation. The gut-brain connection, particularly the role of the vagus nerve, means that an unhealthy gut can disrupt serotonin and cortisol regulation, both crucial to emotional balance. Diets high in sugar or simple carbohydrates often lead to blood sugar spikes and crashes, causing mood swings and restlessness. Feeding your dog high-quality protein, healthy fats, fibre-rich ingredients and probiotics is a solid foundation for supporting both mental and physical wellness.

What are the most common signs that a dog’s food isn’t meeting their nutritional needs?

Dogs will usually show clear signs when their diet is lacking. Issues such as bad breath, skin problems, diarrhoea, vomiting, constipation, and excess gas can indicate digestive distress. Dogs may gain or lose weight unexpectedly, show low energy, or sleep excessively. Their immune systems may weaken, making them more prone to infections or slow healing. Dental issues can also develop. You might also notice changes in behaviour—some dogs become irritable or hyperactive, while others constantly search for food. In cases where dogs struggle to absorb nutrients properly, you may even see them eating faeces, which is often a sign of nutrient deficiency.

Are there specific ingredients or types of food that help calm anxious or hyperactive dogs?

Yes, and surprisingly, it’s not just about ingredients—chewing behaviour itself can have a therapeutic effect. Chewing long-lasting treats or raw meaty bones releases serotonin, which calms the nervous system and improves mood. Foods that contain tryptophan, such as turkey, eggs, and oily fish, help support serotonin production. Magnesium-rich foods like spinach and kale are excellent for calming the nervous system. Complex carbohydrates like oats and sweet potatoes support steady energy by avoiding sugar spikes. Gut health also plays a vital role, and probiotic-rich foods like kefir, green tripe, goat’s milk and natural yoghurt help maintain a balanced gut biome. Some dogs also benefit from herbal supplements containing ashwagandha or lion’s mane mushroom, which support neurological health.

Some dogs sleep a lot, others struggle to settle—can what they eat during the day affect their sleep cycle?

Yes, diet can have a huge effect on sleep. Dogs fed highly processed, carbohydrate-heavy meals may feel bloated or sluggish, especially after large meals. A morning meal of dry kibble, for example, may cause a dog to sleep soon after due to the effort required for digestion. These types of foods take hours to break down, which can throw off their energy rhythm for the rest of the day. Dogs fed nutrient-dense, easily digestible food tend to have more stable energy and better sleep cycles. Feeding times also matter—feeding too late in the evening or too early in the morning without allowing time for physical activity or toileting can contribute to restlessness and anxiety.

How much does sugar or carbohydrate content in dog food influence energy spikes or crashes?

It has a major impact. High-sugar or simple-carb ingredients, such as white rice, corn syrup or molasses, cause rapid increases in blood sugar levels. These spikes are often followed by energy crashes that can lead to hyperactivity, irritability or even lethargy. Many commercial dog foods are packed with these unnecessary fillers to make them more palatable, but they contribute little to a dog’s overall health. Over time, these constant fluctuations in blood sugar can negatively affect mood, energy levels and even long-term metabolic health. For this reason, it’s best to minimise processed carbohydrates, especially low-quality ones like wheat, corn and refined grains.

What’s your view on raw vs. commercial diets when it comes to supporting mental health and stable energy levels in dogs?

if you fix the gut, everything else improves. Raw diets, which include fresh, whole foods, offer natural enzymes, bioavailable nutrients and quality fats that support both the gut and the brain. When the gut is functioning well, dogs are better able to regulate cortisol levels and produce serotonin. Fresh foods like tripe and oily fish are particularly good at providing these building blocks. Raw diets also include nutrients in forms that are easily absorbed and utilised by the body. While not everyone can feed raw, those who opt for commercial diets should choose the highest quality possible. Look for products registered with the Department of Agriculture that include added omega-3s and tryptophan, which may help support emotional stability and cognitive function.

What simple dietary changes can dog owners make today to support better behaviour, sleep, or emotional balance?

Start by adding sardines or sprats—small oily fish that are rich in omega-3s—into your dog’s meals. These essential fatty acids are often missing from both raw and commercial diets. If your dog still has good teeth, raw meaty bones, dehydrated tracheas, cow heels, chicken feet or necks are excellent additions for both dental health and emotional balance. You can also enhance commercial food with whole food toppers such as scrambled eggs or cooked turkey. For fibre, try cooked oats, which help stabilise blood sugar and improve digestion. Avoid processed treats high in sugar. Instead, offer blueberries, carrots or freeze-dried meat as healthy alternatives. Ensure your dog has access to clean, fresh water at all times, and try to feed them at consistent times each day. Portion control is also essential—monitor their body condition and adjust as needed, ideally with guidance from a qualified nutritionist.

Your dog’s food is more than just fuel—it’s one of the most powerful tools you have to support their behaviour, mood and quality of life. By making informed, mindful choices about their diet, you can give your dog the physical and emotional foundation they need to thrive.