Good Behaviour Starts In The Gut

• Dog Behaviour

As discussed in our previous blog, ‘How Does Diet Affect Behaviour,’ nutrition is rarely considered as a contributing factor for problem behaviours. Yet, the gut and brain are linked more closely than you may think.

The Gut-Brain Axis

The hypothalamic-pituitary-adrenal (HPA) axis regulates a vast array of behavioural processes, such as the stress response, memory, and learning (1). The gut and brain communicate directly with each other via neurotransmitters.

Gut health impacts the composition of the gut microbiome which can affect mood, trainability, and energy levels (2). An imbalance in the microbiome (dysbiosis) can result in chronic inflammation, which can alter neurotransmitter function and affect behaviour (3). As most serotonin is produced in the gut, an inevitable consequence of gut dysbiosis is an impact on behaviour. Gut dysbiosis can also contribute to production of inflammatory proteins which activate the HPA axis (4). Elevated levels of these inflammatory proteins have been linked to aggression in dogs (5).

The frequent link between stress-related issues, such as anxiety, with gastrointestinal disorders are further evidence of the gut-brain axis (6). Dogs with irritable bowel syndrome (IBS) may experience behavioural changes, as imbalances in the gut bacteria are connected not only to physical symptoms but also to serotonin levels in the brain (7).

Probiotics

The role of probiotics to influence behaviour is an interesting concept, especially in cases of dogs with chronic gut conditions such as IBS (8). A study on the supplementation of Lactobacillus and Bifidobacterium in humans and rats showed that these probiotics reduced anxiety and decreased serum cortisol levels (9). Lactobacillus and Bifidobacterium produce GABA, a calming neurotransmitter which can decrease anxiety (10).  Lactobacillus acidophilus is the most used bacteria in probiotic supplements. It is abundant in green tripe and has been shown to boost the gut flora and support digestive health of dogs.

Why Does Diet Matter?

One study looked at the link between diet and negative behaviours in dogs, and found that 86% of those exhibiting such behaviours were dry-fed (11). Of those who switched to a complete raw diet, with the inclusion of raw meaty bone chews a few times a week, 98% reported a dramatic improvement in their dog’s behaviour.

Energy Content and Composition

The energy content and macronutrient composition of a diet impacts the activity levels of the dog eating it (12). A balanced diet which supports gut health is an important aspect in managing behaviour.

High levels of simple, refined carbohydrates cause rapid blood sugar fluctuations and can lead to erratic behaviour and energy slumps. Carbohydrates included in a dog’s diet should be complex carbohydrates, with a low glycaemic index. These contain fibre (a good source of prebiotics to support the gut microbiome (3)) and release energy slowly, avoiding spikes in blood glucose.

Feeding a high protein diet offers your dog significantly more satiety than other diets, keeping them fuller for longer, and offering a sustained energy release (13).

Vitamin availability is also key for a happy dog. Vitamin B6 (pyridoxine) is required for the conversion of tryptophan to serotonin and melatonin, and other B vitamins are important for absorption of B6, making vitamin B complex important for a balanced mind (14).

Fatty Acids 

Salmon oil is an excellent source of polyunsaturated fatty acids. The most important omega-3 fatty acids provided are Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA). DHA in particular supports cognitive health and development. Like ourselves, our dogs cannot produce their own EPA and DHA naturally and it should be included in the diet. Compared to normal dogs, aggressive dogs showed significantly lower DHA concentrations, and a higher Omega-6:Omega-3 ratio (5). Thus, low levels of Omega-3 in the diet could be linked to aggressive and inappropriate behaviours.

Ingredient Quality

Not only can the nutritional profile of a food affect a dog’s behaviour, but so can ingredient sourcing. Interestingly, bone meal derived from intensively farmed chicken meat and bone have been shown to induce inflammatory proteins (15), which have been linked to aggression and negative behaviour in dogs. Continuous intake of such food is suggested to affect overall homeostasis of animals – triggering behavioural changes such as anxiety and depression (16).

Chewing As A Form Of Enrichment

Chewing a treat or bone allows dogs the chance to exhibit natural behaviour and provides enrichment, releasing endorphins such as dopamine, which keeps them happy and relaxed! This can be a good calming tool to use when dogs are anxious – not to mention they provide a tasty snack.

Lucy James, BSc (Hons) Bioveterinary Science

Looking to enhance your pet’s diet? Take a look at Cotswold RAW’s range of raw dog food and cat food, including raw meaty bones, dried treats, and puppy food.

References

  1. Kielbik, P. and Witokska-Pilaszewicz, O. (2024) ‘The Relationship between Canine Behavioural Disorders and Gut Microbiome and Future Therapeutic Perspectives,’ Animals, 14(14), 2048. Available at: https://pubmed.ncbi.nlm.nih.gov/39061510/
  2. Goncalves, S. et al. (2022) ‘Enzyme Promiscuity in Serotonin Biosynthesis, From Bacteria to Plants and Humans,’ Frontiers, 13, 873555. Available at: file:///C:/Users/User/Downloads/fmicb-13-873555.pdf
  3. Creech, R. (2024) ‘The link between gut microbiome and behaviour in dogs,’ dvm360, 55(11). Available at: https://www.dvm360.com/view/the-link-between-gut-microbiome-and-behavior-in-dogs
  4. Banks, W. A. (2005) ‘Blood-Brain Barrier Transport of Cytokines: A Mechanism for Neuropathology,’ Current Pharmaceutical Design, 11(8), 973-984. Available at: https://doi.org/10.2174/1381612053381684
  5. Re, S. et al. (2009) ‘Association of inflammatory markers elevation with aggressive behaviour in domestic dogs,’ Journal of Ethology, 27, 31-33. Available at: https://link.springer.com/article/10.1007/s10164-007-0079-3#citeas
  6. Camara, R. J. A. et al. (2009) ‘The Role of Psychological Stress in Inflammatory Bowel Disease: Quality Assessment of Methods of 18 Prospective Studies and Suggestions for Future Research,’ Digestion, 80(2), 129-139. Available at: https://karger.com/dig/article-abstract/80/2/129/105058/The-Role-of-Psychological-Stress-in-Inflammatory?redirectedFrom=fulltext
  7. Spiller, R. (2008) ‘Serotonin and GI clinical disorders,’ Neuropharmacology, 55(6), 1072-1080. Available at: https://www.sciencedirect.com/science/article/abs/pii/S0028390808002906?via%3Dihub
  8. Logan, A. C. and Katzman, M. (2005) ‘Major depressive disorder: probiotics may be an adjuvant therapy,’ Medical Hypotheses, 64(3), 533-538. Available at: https://www.sciencedirect.com/science/article/abs/pii/S0306987704004967?via%3Dihub
  9. Messaoudi, M. et al. (2011) ‘Assessment of psychotropic-like properties of a probiotic formulation (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175) in rats and human subjects,’ British Journal of Nutrition, 105(5), 755-764. Available at: https://www.cambridge.org/core/services/aop-cambridge-core/content/view/2BD9977C6DB7EA40FC9FFA1933C024EA/S0007114510004319a.pdf/assessment-of-psychotropic-like-properties-of-a-probiotic-formulation-lactobacillus-helveticus-r0052-and-bifidobacterium-longum-r0175-in-rats-and-human-subjects.pdf  
  10. Strandwitz, P. (2019) ‘Neurotransmitter modulation by the gut microbiota,’ Brain Research, 15(1693), 128-133. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC6005194/  
  11. Anderson, G. and Mariner, S. (1971). The Effect of Food and Restricted Exercise on Behaviour Problems in Dogs. Canine Academy, KwaZulu natal, South Africa; Zoology Department of the university of Durban Westville, South Africa.
  12. Harju, C. (2016) ‘Dietary Impact on Canine Behaviour,’ Swedish University of Agricultural Sciences. Available at: https://stud.epsilon.slu.se/9460/1/harju_c_160825.pdf  
  13. Heuberger, R. and Wakshlag, J. (2011) ‘The Relationship of Feeding Patterns and Obesity in Dogs’ Journal of Animal Physiology and Nutrition, 95(1), 98-105. Available at: https://pubmed.ncbi.nlm.nih.gov/20662965/  
  14. Hoffmann LaRoche F. T. (1995). Paper presented at the Science and Technology Centre, Hills Pet Nutrition Inc. on “Vitamin Stability in Canned and Extruded Pet Food. Cited in Hand et al. 2010 Chapter 8.
  15. Odore, R. et al. (2015) ‘Cytotoxic effects of oxytetracycline residues in the bones of broiler chickens following therapeutic oral administration of a water formulation,’ Poultry Science, 94(8), 1979-1985. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC4988533/
  16. Maier, S. F. and Watkins, L. R. (1998) ‘Cytokines for psychologists: implications of bidirectional immune-to-brain communication for understanding behaviour, mood, and cognition,’ Psychological Review, 105(1), 83-107. Available at: https://doi.org/10.1037/0033-295x.105.1.83