Did you know what you feed your dog affects its behaviour? Yes, that’s right. What you feed your dog affects how it behaves.

There is increasing evidence that there is a link between negative behaviour and poor gut health in humans and in dogs. It’s all about microbiomes.

Microbiomes affect
• Mood
• Emotion
• Learning
• Central nervous system
• Memory

Microbiomes are microorganisms that live in the gut. They include billions of bacteria, viruses and fungi. We have them, dogs have them. They play a vital role in the ecosystem and in the normal, healthy function of you and your dog’s behaviour. Diet and nutrition affects the microbiomes both negatively and positively depending on what you feed your dog. Therefore you directly influence the physical health and mental health of your dog by what you put in its bowl.

Dogs are canines. Raw meat is what canines, including your dog, eat naturally in the wild. Raw meat contains higher numbers of microbiomes than kibble because it hasn’t been processed or cooked and so the bacteria can survive on the meat. Heat kills bacteria and kibble (dry dog food) has been processed and heated to varying degrees. This means that a lot of the natural bacteria have been killed off during the cooking process. It is the same for us when we cook vegetables; we lose much of the nutrients in the cooking process and so raw or lightly steamed vegetables are much more beneficial. So when we feed dogs a natural, raw diet, we are providing them with plenty of microbiomes that they need to maintain a healthy gut. When we feed kibble, the gut isn’t getting the appropriate microbiomes that it needs and therefore cannot function properly.

• Meat contains essential amino acids such as tryptophan. Tryptophan produces serotonin (the happy hormone) and melatonin (the sleepy hormone). Many dogs nowadays are not getting enough sleep. This is partly due to lifestyle but partly due to energy levels from the diet. I see it all the time during my consultations, high-energy dogs that can’t settle. I recommend they go onto a raw diet and with behaviour modification they suddenly start relaxing and sleeping more within a matter of days.
• Another important amino acid is tyrosine, found in fish and eggs. It produces dopamine (pleasure hormone) and noradrenaline (needed for stress, or fight or flight). Humans and dogs need tyrosine to feel happy and to cope with stress.
• Processed meat, cooked meat, heated meat, poor quality meat have much LESS amino acids.
• Raw foods that are high in fat produce lower blood fat than a low-fat kibble

Happy gut = happy brain. Unhappy gut = unhappy brain.

Most kibble is cooked under high pressure and high temperature, killing off most of the good stuff, meaning the dog is missing out on these essential acids.

Here are some interesting facts about the gut.

• 90% of SEROTONIN (the happy hormone) is created in the gut by enterochromaffin (EC) cells.
• I’m going to repeat that one! 90% OF SERATONIN IS CREATED IN THE GUT. Think about that if you have an anxious or aggressive dog.
• EC cells from germ-free lab mice produced 60% LESS serotonin than mice with bacteria in the gut. When the mice guts were recolonised with bacteria, the serotonin levels went back to normal, showing that deficit of serotonin can be reversed with bacteria! When we give our dogs antibiotics we are killing off all the EC cells in the gut. True, mice and dogs are different creatures, but the principles of the gut bacteria still apply.
• The gut bacteria travel UP the vagus nerve and into the brain. (2), (3) (4). This means that whatever is in the dogs’ stomach directly affects the brain.
• There is a proven link between poor diet (poor gut health) and antisocial behaviour in humans. (5)
• Evidence suggests that in humans, sugar, low micronutrients, E-numbers, food additives and food dyes affect the gut, which affect the brain, which affect behaviour. (6)

So you can see how important it is that the gut is kept healthy.

Here are some interesting facts about dog health. (1)

• 1 out of every 2 dogs die of cancer
• 4 out of every 5 dogs aged 2 get a periodontal (gum) disease
• 70% of dogs are overweight or obese
• High blood fats cause pancreatitis

So what SHOULD we be feeding our dogs? Dogs’ teeth, stomachs and digestive systems have not changed in thousands of years of evolution. Dogs are canines; their diet should be one of a carnivore. Carnivores eat largely raw meat including bone, some grasses, greens, berries that they scavenge and from the gut of the animals they have eaten. And they have a VARIETY of different meats.

80% RAW meat – flesh, skin/hide, organs, fur, bone, hoof, blood, shellfish, fish
20% vegetables, nuts, herbs, seeds, oils, dark berries

Meat can be given whole or ground into a mince. Many raw food suppliers have a great selection including meat & veg minces. Fresh, raw vegetables can be blended at home to retain nutrients, or lightly steamed. Most nuts are safe to give (do not feed macadamia nuts to dogs) and seeds like pumpkin seeds or flaxseeds are great for providing oils, and should be ground in a coffee blender, to ensure proper absorption into the gut.

There are many fantastic supplements available to add to dog food to make up the requirement for nuts, herbs and seeds, such as Proflax or Hedgerow Hounds. For dog treats use anything dried. Cartilige is a great source of microbiomes for developing puppies and older dogs. Animal fur contains manganese. Manganese is great for bone health. Manganese isn’t found in the flesh of an animal but on the fur, so a whole rabbit or rabbit ears are a good source because the fur is in-tact.


If you are already feeding your dog raw then great! But consider variety and adding some supplements to make sure your dog is getting a really good balanced diet of meat, oils and vegetables. If you are currently feeding kibble AND your dog is anxious or aggressive, it is worth looking at diet as well as behaviour modification to help improve behaviour. Even if your dog is on kibble and not anxious or aggressive, consider swapping to raw. If you are vegetarian or simply cannot stomach raw food then fresh, cooked meat, is a good alternative.

Dog poo is a really good indicator of health, if your dogs poo is soft, runny, very stinky, hard to pick up and if your dog farts a lot, it is a sign that the gut health of your dog is not good. Dog poo should be firm, easy to pick up and not too smelly and there should be no stinky farts.

Changing to a raw diet can produce positive results really quickly. Skin, teeth, the coat and the brightness in the eyes can change within days as can mood. Many people report reduction in allergic symptoms and along with behaviour modification I hear reports of a dramatic change in overactive hyper behaviour.

Years ago dogs seemed to be healthier and there wasn’t so much of an issue around aggression. I believe that there is a link with diet and behaviour (among other things I won’t get into here), but diet plays a really big part.

If you are considering switching to raw from kibble and are unsure, talk to your local raw food stockist, or post a question here and I’ll do my best to help. Do your own research and make an informed decision. Some people worry about the risk of contamination or E-Coli in feeding raw. I have fed raw for years and have never had any problems. Sensible hygiene protocols should apply of course, disinfect utensils and surfaces and don’t leave raw food lying around. You will need a freezer. I order a months’ supply and defrost the next day’s dinner overnight.

If your dog is prone to food aggression then a raw diet may not be advisable as it is “high value”, speak to me or any other behaviourist if you are unsure.

Sometimes dogs that have been fed kibble all their lives don’t know how to take to the raw diet. My rescue dogs didn’t eat the raw food at first, so I cooked it in the oven and served it cool then cooked it less and less over a few days until it was raw. From then on the dogs loved it and can’t get enough of it.

For anyone that is completely anti feeding raw then I recommend a good quality grain-free kibble. Buy the best that you can afford and check the label. Look for a product that has at least 40% meat/fish as its first ingredient and avoid anything that says DERIVATIVES, this is vague, non-descript and usually the garbage left over from the animal. One well known popular brand has 4% meat derivatives in the ingredients. This is such low quantities of meat that the dog is getting virtually no meat. Some kibble manufacturers are cooking the product at a low temperature to retain some of the microbiomes.

My advice as a behaviourist is not just about training and behaviour, I put a lot of emphasis on making the dog feel physically healthy and as comfortable as possible. If a dog has an irritated stomach, feels uncomfortable or has indigestion, it is more likely to be snappy or aggressive. I always review diet when working with anxious, aggressive or hyperactive dogs.

For anyone that does make the change, enjoy the benefits and just watch your dog glow!

Supplementary suggestions

https://www.hedgerowhounds.co.uk/ Herb supplement
https://www.aniforte.co.uk/products/barf-complete Seaweed, herbs, seeds
https://www.nutravet.co.uk/ Vitamins, minerals, oils
https://proflax.co.uk/ Herbs and oils
http://www.grizzlypetproducts.eu/products/ Salmon fish oil
https://dogsfirst.ie/seaweed-for-dogs/ Seaweed, kelp

(1). Dr. Nick Thompson BSc (Vet Sci) Hons, BVM&S, VetMFHom, MRCVS, Brains, Bowls and Bull
(2). https://www.pnas.org/content/108/38/16050
(3). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4367209/
(4). https://www.sciencemag.org/news/2018/11/do-gut-bacteria-make-second-home-our-brains
(5). https://www.ncbi.nlm.nih.gov/pubmed/12091259
(6). www.gaps.me