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You Are What You Eat

How the ingredients in food can affect and treat behavior problems in pets.

Dr. Amy Learn DVM
Source: Dr. Amy Learn DVM

I was contemplating this article while delivering eight dozen donuts to local hospitals thanking them for supporting my referral practice. As I was driving around, the heavenly smell of fresh, warm, sugary donuts surrounded me. It was then that I seriously wondered if I could live on donuts alone. Ok, maybe donuts and bacon…

Concerns about diet and nutrition are rapidly becoming more mainstream as we are bombarded with messages to eliminate processed foods, choose organic, be a strict vegan, or follow other dietary lifestyles. Consumers are also following those trends for their pets. Unfortunately, these choices may be based on the current popular craze, without scientific research, and could even potentially be harmful. The shelves of pet stores and veterinary offices are filled with supplements touted to increase health, vitality, memory, immune function and more. But is there actual science to support the use of these supplements? Can what we eat affect our emotional state or responses? Let’s take a look at some of the most common ingredients and how they affect behavior. Then we will target emotional responses to food.


One ingredient that is the topic of much debate is tryptophan. Tryptophan is an amino acid used in the synthesis of proteins. It is also the precursor that our bodies use to make the neurotransmitter serotonin (your stress-relief neurotransmitter) and the hormone melatonin. It is most commonly found in oats, dairy products, eggs, red meat, fish, poultry, and some seeds and nuts. Tryptophan does not enter the brain easily because it must compete with other large amino acids absorbed from the diet to cross a little blockade called the blood-brain barrier (BBB). One study in dogs showed that a certain type of aggression called dominance aggression was significantly greater when the dogs were fed the higher protein diet. This might lead you to believe that feeding your dog a lower protein diet will make him happier but that is not actually the case, and if you feed him only donuts he will get very sick.

Polyunsaturated Fatty Acids

Some of the behavior disorders we see in animals may be the result of maternal malnutrition. When I was pregnant with my daughter, my doctor advised me to increase my intake of Polyunsaturated Fatty Acids (PUFAs) to ensure proper development of my little babushka. Similarly, kittens and puppies who do not receive proper PUFA support do not develop normally, increasing the likelihood of retarded growth or mental capacity, and increased fear or aggression. In addition, if the mother doesn’t receive proper amounts of protein in her diet, puppies may be more likely to be nervous and resistant to handling.

It is clear that PUFAs are essential for brain development of the fetus, but these natural anti-inflammatories are also recommended to increase memory, heart, skin, and joint health. In fact, high levels of fatty acids have been used successfully in several commercial and prescription diets including Hill’s Prescription Diet Canine b/d. In my daily practice, I can’t remember the last time a day went by that I didn’t recommend at least once that a client add fatty acids to their pet’s diet.


Another nutrient used in a therapeutic manner is fiber. As in,"we all need more fiber in our diet to stay regular". Now, that completely goes against my donut and bacon plan, but may be healthier. Some of our feline friends suffer from a condition called pica (an appetite for nonfood items). Fiber supplementation is often used to treat this condition.

Medium-Chain Triglycerides (MCT)

Aging is commonly associated with declined efficiency of glucose metabolism by the brain. Ketones provide an alternative energy source for the brain’s metabolic activities. In one study, dogs receiving an MCT supplemented diet showed significantly elevated levels of beta-hydroxybutyrate, a ketone body. These study results indicate that long-term supplementation with MCTs increases circulating levels of ketones and that this effect improves cognition. This is the premise behind Purina’s Prescription diet Neurocaretm which is formulated to nutritionally manage dogs with epilepsy and cognitive dysfunction.

Now that we have discussed that many nutrients can contribute to bodily health, let's investigate how they can contribute to emotional health. At this point, I want to get back to my donut issue. There are many things that I may be apprehensive about doing in which having a donut may help me feel better about. This is one of the cornerstones of the Fear Freesm movement in veterinary medicine. How can we make a vet visit more fun and less stressful for the pet? Pediatric dentists have latched onto this paradigm shift with steel claws. My daughter has her teeth cleaned wearing princess sunglasses, watching the latest Disney movie on the screen above her head, and with a plethora of choices in toothpaste flavors. Afterwards, she gets a balloon and a coin for a special prize that she redeems at the check-out desk. Using food during veterinary visits to counter-condition (changing a negative emotional response to a positive emotional response) is essential. If children can love the dentist, our pets can love the vet. I consistently leave the exam room covered with peanut butter, cheese, freeze dried chicken crumbs, and dog saliva because my patients love coming to see me. (For more information about Fear Freesm veterinary visits, visit

Food, glorious food, is a very powerful tool whether you are talking about the health benefits or the emotional ones. Considering what nutrients go into our bodies and where they come from is an important consideration. Clearly, there are even more nutrients out therethat are pertinent to discuss so maybe we will catch up with each other another time. For now, I have more donuts to deliver and miles to go before I sleep. Mmmmm, donuts.

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