18/08/2025
𝐁𝐞𝐭𝐭𝐞𝐫 𝐅𝐨𝐨𝐝, 𝐁𝐞𝐭𝐭𝐞𝐫 𝐁𝐞𝐡𝐚𝐯𝐢𝐨𝐮𝐫𝐬, 𝐁𝐞𝐭𝐭𝐞𝐫 𝐃𝐨𝐠𝐬
Anxiety, fear and aggression in dogs is complex. It isn’t solved by just one thing — it’s a psycho-physiological condition influenced by both body and mind. One important and often underrated pathways in influencing behaviour is the 𝑔𝑢𝑡–𝑏𝑟𝑎𝑖𝑛 𝑎𝑥𝑖𝑠.
🧠 𝑻𝒉𝒆 𝑮𝒖𝒕–𝑩𝒓𝒂𝒊𝒏 𝑨𝒙𝒊𝒔
The gut and brain communicate through the vagus nerve — the body’s longest nerve, stretching from the brainstem to the abdomen. This nerve regulates swallowing, heart rate, breathing, gut motility, and gland secretion as part of the autonomic nervous system, which balances:
▪️Sympathetic tone (fight or flight)
▪️Parasympathetic tone (rest and digest)
Because dogs and humans share similar neurotransmitters, the same drugs (e.g. Prozac, trazodone) can work in both species.
Up to 90% of serotonin — the neurotransmitter linked to mood, memory, and wellbeing — is produced in the gut. This is why the gut is often called the “second brain.” Stress can affect the gut (e.g. dogs exhibiting stress diarrhoea after moving house), and the gut can affect the brain through the activity of the microbiome.
🦠 𝑻𝒉𝒆 𝑴𝒊𝒄𝒓𝒐𝒃𝒊𝒐𝒎𝒆 𝒂𝒏𝒅 𝑩𝒆𝒉𝒂𝒗𝒊𝒐𝒖𝒓
The microbiome is made up of bacteria, fungi, viruses, and their genes. Different microbial populations live in the mouth, skin, nasal passages, urinary tract, and gut — but the gut microbiome has the most profound impact on behaviour.
Gut microbes communicate with the brain via the vagus nerve. They produce metabolites and neurotransmitters that directly influence mood, resilience, and emotional stability.
▪️A healthy microbiome supports a strong gut lining (epithelium) and balanced immunity.
▪️Dysbiosis (imbalance of microbes) is linked to gastrointestinal issues and behavioural problems such as: separation anxiety, reactivity, aggression, excessive licking/barking, hyperactivity, coprophagia, allergies, and reduced stress resilience.
Stress itself can worsen dysbiosis, creating a cycle of imbalance.
Since 75–80% of the immune system resides in the gut (in gut-associated lymphoid tissue), maintaining microbial diversity is crucial.
⚖️ 𝑵𝒖𝒕𝒓𝒊𝒕𝒊𝒐𝒏, 𝑮𝒖𝒕 𝑯𝒆𝒂𝒍𝒕𝒉 & 𝑨𝒏𝒙𝒊𝒆𝒕𝒚
Diet plays a major role in shaping the microbiome and behaviour:
▪️𝐇𝐢𝐠𝐡 𝐜𝐚𝐫𝐛𝐨𝐡𝐲𝐝𝐫𝐚𝐭𝐞 𝐝𝐢𝐞𝐭𝐬 (such as kibble, often 30–60% carbs) can spike blood sugar, leading to hyperactivity. Low blood sugar that follows can impair brain function, sometimes triggering aggression. Carbohydrate-driven inflammation also worsens anxiety.
▪️𝐎𝐦𝐞𝐠𝐚-𝟑𝐬 (𝐄𝐏𝐀 & 𝐃𝐇𝐀) are vital for brain health. Low DHA has been linked to aggression in dogs. Choose clean, sustainable sources (marine algae, green-lipped mussel) to avoid heavy metals.
▪️𝐌𝐂𝐓 𝐨𝐢𝐥 supports cognition in senior dogs and may reduce anxiety.
▪️𝐁 𝐯𝐢𝐭𝐚𝐦𝐢𝐧𝐬 (especially B6 and riboflavin) are essential for serotonin synthesis.
▪️𝐌𝐚𝐠𝐧𝐞𝐬𝐢𝐮𝐦 regulates neurotransmitters and promotes calmness.
▪️𝐙𝐢𝐧𝐜 𝐚𝐧𝐝 𝐢𝐫𝐨𝐧 are required for normal brain function — deficiencies are linked with aggression, destructive behaviour, and fearfulness.
Protein balance matters, too:
▪️𝐓𝐫𝐲𝐩𝐭𝐨𝐩𝐡𝐚𝐧 is a precursor to serotonin, supporting calm mood and learning.
▪️𝐓𝐲𝐫𝐨𝐬𝐢𝐧𝐞 is a precursor to dopamine and norepinephrine, which drive arousal, agitation, and anxiety if unbalanced.
▪️Since tryptophan and tyrosine compete to cross the blood–brain barrier, diets too heavy in certain proteins may favour arousal chemicals over calming ones.
For raw-fed dogs with anxiety or aggression, small dietary adjustments can help:
▪️Feed twice daily
▪️Include an easy-to-digest carbohydrate (e.g. sweet potato, rice if tolerated)
▪️Ensure adequate B6 from natural sources like liver, or appropriate supplement (1 mg/kg)
▪️Offer a small carbohydrate snack 2–3 hrs after meals
Noticeable improvement may appear within a week, with long term results after 3 months at which the diet can be rebalanced.
🌱 𝑺𝒖𝒑𝒑𝒐𝒓𝒕𝒊𝒏𝒈 𝒕𝒉𝒆 𝑮𝒖𝒕–𝑩𝒓𝒂𝒊𝒏 𝑨𝒙𝒊𝒔
▪️Probiotics & prebiotics (including soil-based organisms and Saccharomyces boulardii)
▪️Fermented foods (for microbial diversity)
▪️Real, species-appropriate whole foods (avoid preservatives, dyes, rancid fats, pesticides, and mycotoxins)
▪️Stress reduction & exercise (stress alone alters gut motility and the microbiome)
▪️Fecal microbiota transplant (FMT) — early veterinary research and case reports show changes in personality, resilience, and vitality.
▪️Reduce environmental toxins — pesticides, flea/tick preventatives, unnecessary antibiotics, and heavily processed foods all harm microbial diversity.
👩⚕️ 𝑩𝒆𝒚𝒐𝒏𝒅 𝒕𝒉𝒆 𝑮𝒖𝒕
A full program for canine anxiety should combine nutrition, gut health, complementary therapies (acupuncture, massage, herbs, nutraceuticals, pheromones, CBD, mushrooms), and training.
Training gives dogs safety, boundaries, and partnership. But the foundation of calm behaviour often begins in the gut.
👉 𝑻𝒂𝒌𝒆𝒂𝒘𝒂𝒚: For dogs with anxiety, the gut–brain axis should be a central focus of care. By supporting microbiome diversity, balancing nutrition, and reducing toxins, we can help build emotional resilience — and a calmer, healthier companion.
