By: Sarah Wallace, DVM, Pet Nutrition Coach Certified, Fear Free Certified, and Human-Animal Bond Certified


It has been well established that eating a complete and balanced diet of whole foods is the best way to ensure overall health. This is also true for our pets. Minimizing or eliminating highly processed foods and sugary or simple-carbohydrate foods allow our bodies and minds to function at their best, in both humans and our pets. Poor diet results in an unbalanced and possibly nutrient-deficient body. An unhealthy body is more likely to become stressed, exhibit inflammation, or manifest disease.


Pre-prepared pet foods have fixed recipes making it difficult to control what your pet is eating. When so many pet owners rely on pre-prepared foods for their pets, it may seem moot to discuss how diet can affect anxiety and stress. However, this article will discuss the connection between diet and behavior, the effect of food preparation, and individual ingredients that can help with behavioral concerns.


Feed A Complete and Balanced Diet


A complete and balanced diet contains lean meats, low-glycemic index carbohydrates, fruits/vegetables, healthy fats, and adequate amounts of vitamins and minerals to achieve daily consumption requirements for dogs. A diet missing one or more of these crucial elements may not be able to provide your pet with the nutrients they need to remain healthy. Nutrient deficiencies can cause a variety of medical conditions that can exacerbate feelings of stress or anxiety.


Inadequate protein levels in a diet, for example, may result in the breakdown of body muscles to ensure there are appropriate levels of protein in the blood. Loss of muscle mass will lead to weakness. Weakness can lead to stress when that dog cannot exercise or play like they used to.


Inappropriate carbohydrate intake can also add to anxiety. When feeding simple carbohydrates (high glycemic index), the body experiences a rapid introduction of sugars into the body. When the body’s sugar levels spike, so do a dog’s feelings of stress and anxiety.


Pets need certain levels of dietary fat, but they need to be within appropriate levels for individual dogs and need to be in precise proportions to prevent a bodily inflammatory response. Excess fat in the body can also create an overweight pet. Overweight and obese pets have additional potential for medical conditions such as osteoarthritis (painful) and diabetes (stress that comes from high or low blood sugar levels) that can both add to overall stress and anxiety.


Although important to always feed a complete and balanced diet, alone, this recommendation will only ensure that unnecessary anxiety and stress are not caused by a lack of appropriate nutrients. Once we ensure that they are getting all the nutrients they need on a daily basis, we can then focus on food preparation and individual food ingredients that can potentially help with stress and anxiety.


What Does Inflammation Have to Do with Behavior?


Inflammation is one of the most common ways that the body responds to abnormality, injury, or change. Inflammation refers to an action by the body to identify something abnormal, bring in immune cells (body defense cells) to investigate and rebuild anything that needs fixing. Areas of inflammation in the body can be identified through one or more of the cardinal signs of inflammation: heat, swelling, redness, pain, loss of function. It can be something small, like a small cut or large like Irritable Bowel Disease (IBD). The scientific literature provides us with studies that suggest an increase in inflammation in the body is associated with an increase in anxiety-like behavior in pets. This means that when your pet doesn’t feel well, whatever is causing their illness may also be contributing to their overall stress or anxiety level.


The immune system needs an inflammatory response to protect the body when needed. However, when too much inflammation occurs unnecessarily or occurs chronically (for a long time), that is when stress, anxiety, or behavioral abnormalities may surface. A recent study demonstrated a connection between environmental allergies and behavioral concerns. Environmental allergies in dogs can cause intense inflammation and itchiness. The study found that when the environmental allergies were treated appropriately to control inflammation and itch, the behavioral concerns resolved.


Inflammation can be dealt with in different ways: Fish oils and antioxidants are two of those methods.


Omega-3 Fatty Acids and Inflammation


The benefits of omega-3 fatty acids in the body center on inflammation. To date, no known studies exist to show that feeding high levels of omega-3 fatty acids (fish oils) have any effect on a pet’s stress and anxiety. However, since we know that body inflammation has a direct effect on stress and anxiety (see inflammation section above), omega-3 fatty acids in appropriate proportions to other oils in the body are anti-inflammatory and can help control body inflammation.


To employ additional omega-3 fatty acids in your pet’s diet, you can add whole food items such as fish oil, salmon, sardines, walnuts, mackerel, chia seeds or flax seeds. Work with your veterinarian to determine the correct quantity of omega-3 you should be feeding your dog. If you want to add additional omega-3 fatty acids into your pet’s diet, consider that many commercial wet or dry foods have fish oil included in the recipe – be sure to take that extra fish oil into consideration when considering supplementing extra fish oil. For additional inflammation about appropriate fatty acids and inflammation in your dog, look at the Tufts Veterinary Nutrition Website.


Antioxidants and Inflammation


Antioxidants are foods that can minimize inflammation by gathering and disarming inflammation-creating molecules called “free-radicals” in the body. There are many foods that are considered to have antioxidant properties. Antioxidant foods can be used as part of a homemade diet or can be added as a “topper” to the current food. As mentioned earlier, an increase in inflammation is associated with an increase in anxiety behaviors. Antioxidant foods may be able to help in this regard. Minerals such as selenium, manganese, zinc, and copper also have the ability to decrease inflammation through scavenging free-radicals. If the diet you are feeding is complete and balanced, these minerals will already be present in appropriate levels and will already have this beneficial effect.


If you would like to add additional antioxidants to your pet’s diet, you can do so by adding ingredients such as pecans, blueberries, strawberries, artichokes, Goji berries, raspberries, kale, red cabbage, beans, beets, and spinach. These foods can be fed as snacks or as toppers to your pet’s normal food.*


Western Medicine Approach to Anxiety: Pharmaceuticals and Nutraceuticals


A large part of the Western Medicine’s approach to anxiety and stress conditions centers around pharmaceuticals and nutraceuticals. A majority of the prescription medications used for treating anxiety and stress conditions are “off-label” — being used for a reason other than they were intended. If your pet does not do well with oral medications, however, or you prefer more natural treatments, food can be used to help with anxiety or stress conditions. One source of foods to try are the sources of nutraceuticals currently used in veterinary medicine for treating anxiety. The nutraceuticals available for stress and anxiety in pets has been expounded upon in this article about supplements. Stress/Anxiety supplements are currently added to dog and cat diets and also come in the form of treats, snacks or tinctures. If we wanted a more natural approach to taming fear, anxiety and stress, we should examine where these nutraceuticals come from and if there are any foods we could use for the same effect.


Whole Food Nutraceuticals


Milk Products: Alpha-casozepine and Alpha-lactalbumin


Two milk-derived nutraceuticals that have recently become popular for stress and anxiety relief in pets are Alpha-lactalbumin and Alpha-casozepine.


Alpha-lactalbumin is a small protein that is part of the lactose synthase enzyme — and therefore, present in all milk. This nutraceutical comes from the whey protein in milk and contains large amounts of amino acids like tryptophan, the precursor to serotonin. Serotonin becomes deficient in chronically stressed (people and) pets. So, supplementation of the precursor amino acid tryptophan can help the brain feel more balanced and at peace.


Alpha-casozepine is a small cow-milk-derived protein from the protein casein that causes a calming effect in the body. Alpha-casozepine binds to certain receptors in the nervous system, causing a decrease in their activity, which can decrease anxiety. However, this protein is not easily digested and absorbed without help from nutraceutical processing.


Because each individual pet is different, some pets may see a calming effect when they ingest these milk proteins, and some may not. Anecdotally, some pets experience significant calming while taking the milk-derived protein nutraceuticals. If you wanted to try giving your pet a small amount (a tablespoon for small dogs, ¼ cup for large dogs) of a milk product, it may help with their anxiety. Too much dairy can cause stomach upset (throwing up or not wanting to eat), diarrhea, and can create inflammation in the pancreas called pancreatitis. If your dog is prone to or has previously had a sensitive stomach or pancreatitis, you should try a different method of stress/anxiety reduction. Pets who develop diarrhea, vomiting, or not wanting to eat after being given a milk product should discontinue the milk and can try the nutraceutical instead.




A healthy intestinal tract houses millions of beneficial bacterial colonies that assist with food digestion and intestinal defense. A probiotic refers to living bacteria that are consumed to populate, replenish, or reinforce the bacteria living in the intestines.


Probiotics have been shown to have an intimate role in anxiety and stress through two different body mechanisms. The hypothalamic pituitary axis (HPA Axis) that controls the release of stress hormones in the body and the Gut-Brain Axis that serves as a communication between the gut and the brain itself. The use of probiotics in scientific studies in animals and humans have repeatedly demonstrated a beneficial effect of probiotics on anxiety-related behavior.


To employ probiotics in your pet’s diet, you can introduce them to small amounts (teaspoon-sized dose) of fermented foods such as sauerkraut, kombucha, or milk products such as kefir or yogurt,* and/or supplement their food with a multi-strain probiotic capsule or powder. All pets should be given a probiotic on a daily basis, even more so in pets with anxiety, inflammatory, or immune-related disease. Discuss the dose, dosing schedule, and source of probiotics with your veterinarian before starting.




Tryptophan is an amino acid, the building blocks of proteins. Tryptophan is critical to the body’s production of serotonin and melatonin. Serotonin is one of many chemicals that transmits signals between nerves in the body and specifically helps to balance mood. Melatonin, a hormone involved in the sleep-wake cycle, has shown in numerous scientific studies to have analgesic (pain-relieving), anxiolytic (anxiety-relieving), antioxidant (anti-inflammatory) and cerebral (brain) protective benefits.


Although using foods with additional tryptophan may help your dog’s stress and anxiety, please note that high protein diets (that include more tryptophan) – with protein levels that exceed daily recommended guidelines are not used by the body and, in fact, are broken down and either stored as fat or urinated out as waste.


Also note that the higher the protein level of a diet, the more competition between tryptophan and the other amino acids. More competition means that tryptophan cannot have as much of an effect on the brain and subsequent stress and anxiety levels. Speak with your veterinarian about finding out what protein level is most appropriate for your dog.


To employ foods rich in tryptophan in your dog’s diet, you can include cooked red meats, almonds or walnuts (only one or two individual nuts per day), cooked chicken, cooked turkey, cooked fish, cooked eggs, and/or pumpkin to their diet. Some commercially prepared foods may already have one or more of these ingredients.*




B-Vitamins are water-soluble vitamins used in a variety of body processes, including reactions to keep the nerves, immune cells and blood cells healthy and functioning. Vitamin B-6 (aka Pyridoxine) is important in an enzymatic reaction that builds neurotransmitters – the molecules that help nerves talk to each other. Even more specific, Pyridoxine helps to build serotonin, a neurotransmitter that helps balance mood. If your dog’s diet is complete and balanced, they should have all the B-vitamins they need.


If you would like to add additional B-Vitamins into your pet’s diet, you can include ingredients such as asparagus, leafy greens, meat, and avocado (sparingly, and definitely not the pit)*




L-theanine is an amino acid that is only found in a few places – in most tea leaves (Camellia sinensis) in Holly Plants, and in Boletus badius mushrooms. L-theanine increases the amount of dopamine and serotonin that gets synthesized in the brain and induces relaxation through the enhancement of alpha wave activity in the brain. Scientific results have shown that L-theanine can reduce “stranger-danger” fear, noise phobia, and storm anxieties.


If you were looking to add L-theanine to your pet’s diet, you could do so by adding a small amount of green tea or green tea extract to your pet’s food – or brewing them up a cup of green tea and waiting until the tea is room temperature, then apply a tablespoon to the food of small dogs and up to half a cup to the food of large dogs.


Caffeine is the biggest concern with giving tea to a pet. Ingestion of certain levels of caffeine can be toxic to dogs and cats. Consider, however, one cup of green tea contains between 30 and 50 milligrams of caffeine. In theory, multiplying your pet’s body weight in pounds by 14 will give you the number of milligrams of caffeine they have to ingest to start showing signs of caffeine toxicity. Because each pet is different, however, the toxic effects of caffeine can be seen when your pet ingests even small amounts of caffeine. If you are going to try giving small amounts of green tea to your pet be aware of signs of caffeine toxicity including: hyperactivity, restlessness, throwing up, elevated heart rate and respiratory rate, elevated blood pressure, tremors, seizures and death. If your pet has ingested caffeine and is showing any of these signs, bring them to a veterinarian right away.


Regarding other sources of L-theanine, all parts of the Holly plant are toxic to pets and should never be fed to them. The Boletus mushrooms, although edible for humans, and considered low risk for toxicity, can cause intestinal upset (vomiting, diarrhea, inappetence) in pets. In this case, if you are wanting a natural way to supplement L-theanine, reach for the green tea.


Eastern Medicine Perspective: Energies and Actions of Foods


Eastern Medicine, specifically Traditional Chinese Medicine has specific views on the causes of behavioral abnormalities and anxieties. In Traditional Chinese Veterinary Medicine (TCVM), the “shen” refers to the mind and spirit of an individual. When the shen becomes disturbed, behavioral abnormalities, including anxiety, can result. TCVM teaches that the shen is housed in the heart and is damaged by “heat”. Hot environments, such as living in the south, can cause “heat”, stressful family or social situations can create “heat”, and too much inflammation in the body causes “heat”. With these basic principles in mind, foods can be selected as treats, or toppers to a current meal, as ingredients in a pre-prepared kibble or canned food, or ingredients of an entirely home-cooked diet.


  • Foods that support the heart energy or Qi (pronounced chee), support the cooling energy of the heart and support the shen include:
  • Proteins such as pork heart, beef heart, chicken heart, turkey
  • Carbohydrates such as wheat, brown rice, millet
  • Vegetables such as culinary mushrooms, broccoli, spinach, asparagus
  • Fruit such as kiwi and pitted dates – remove the pit before feeding.


Proteins should be lightly but fully cooked through, carbohydrates should be prepared per package instructions, and vegetables need to be blanched to ensure your pet can break down and absorb the nutrients from them.


If you would like to start adding a few of these food items to your pet’s daily meal, be mindful that if the topper makes up more than 10% of the daily food fed, you have unintentionally unbalanced their regular diet food and are likely not receiving the nutrients they need in the correct proportions. To eliminate this problem, a fully home-made diet could be made using some of the suggested ingredients. It is imperative, however, that any home-made food be vetted by a veterinary nutritionist or TCVM (Traditional Chinese Veterinary Medicine) practitioner who is confident in balancing diets. The consequences of vitamin and mineral deficiencies to pet health can be severe.


If you would like a whole diet created for your pet, TCVM veterinarians can select ingredients specifically for your pet, your pet’s personality or “constitution,” and any medical conditions they may be experiencing – and can more precisely treat your dog or cat. A veterinary nutritionist can then balance the ingredients.


Conclusion: What is the connection between diet and behavior?


Inappropriate behaviors, stress, and anxiety can occur for a variety of reasons in our dogs. Diet can and does play a role in the presence of stress, anxiety, and some behaviors. The overcooked foods fed daily, the level of inflammation in the body, the presence of medical conditions can increase unwanted behaviors and stress levels and can be modified by changing the food that is fed. The most effective way to combat any behavioral abnormalities is to first ensure that the behavior, stress, or anxiety is not of medical origin – so make an appointment with your veterinarian. Then, work on training your dog as directed by your veterinarian or veterinary behaviorist (if applicable) and take a close look at what you are feeding. Try adding some of the food suggestions above to your dog’s normal diet or consider switching to a complete and balanced all-homemade diet with the help of a TCVM practitioner. A lower-stress life for your pet, will make a happier and more fulfilling relationship for you both.


* If you are adding any of the above ingredient recommendations to your pet’s commercially produced diet, remember that everything fed to your dog outside of their normal meal food needs to be less than 10% of their daily food intake. If treats and toppers amount to more than 10% of the normal food intake, you are inadvertently unbalancing their meal food and potentially creating the opportunity for nutrient deficiencies to develop or weight gain.



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