High Carb Diets & Behavior


In 1995 – 1996, I began to notice that a number of the Labrador and Golden Retriever puppies in our puppy kindergarten classes were having trouble holding still. Now, I know puppies wiggle and squirm, and I know Lab and Golden puppies can be particularly wiggly; but these puppies acted as if they not only would not but simply could not hold still. My grandmother would have said these pups had ‘ants in their pants.’ When I mentioned this to Petra and our assistants, they admitted they had noticed this, too, but weren’t sure if it was something new or if they had simply not paid attention to it previously. So we began watching all of the puppies in our puppy classes much more closely and we started making more detailed notes on our class attendance sheets.

In 1996 through 1997, we found that an average of three puppies in each ten to twelve dog puppy class was overly active. When asked to describe their puppy’s personality, each puppy owner said (without prompting), “Hyper,” using of course, the layman’s definition of the word, not a medical definition. When asked to elaborate, the owners invariable said the puppy was overly active, couldn’t hold still, couldn’t concentrate, and on occasion, seemed to suffer from temper tantrums or anger.

The breeds involved varied. There were many more Labrador Retrievers and Golden Retrievers than any other breed, but we also had more of these two breeds enrolled in our training than any other breeds. We also saw wiggly German Shepherd Dogs, Australian Shepherds, Australian Cattle Dogs, Gordon Setters, Irish Setters, Siberian Huskys and Pit Bulls. But this wasn’t limited to purebreds. One of our worst cases was a mix that seemed to have a little of everything – a proverbial All American.

Once we identified that we were actually seeing something, we decided to try and figure out what was going on. We began asking questions and taking notes. Where did you get your puppy? How old was your puppy when you brought it home? Has your puppy been vaccinated, for what (specifically) and how many times? Did your puppy have any reactions to the vaccines? Has your puppy ever been sick? How much exercise does your puppy get on a daily basis? How much interaction with the family? How often (or long) does your puppy spend alone in the back yard? We asked any question we felt might shed some light on what was happening with these puppies and since the puppy owners were often frustrated by their puppy’s behavior, we found that most owners were very honest and forthright with us.

So what did we find? We found only one thing that 99% of these puppies had in common: these puppies were eating premium or supper premium dog foods that were very high in cereal grain carbohydrates. They were not all eating the same brand, and ingredients (including artificial colors and other additives, and preservatives) differed between the various foods and brands, but all were in high in carbohydrates, especially cereal grains.

Researching the Problem

There is very little published on the relationship between high carbohydrate diets and behavior in dogs. However,William Campbell, a noted, well-published behaviorist, has a case history in his BehavioRX Pet Behavior Resources. A seventeen month old large breed dog suffered from hyper-reactivity when exposed to crowds of people and dogs. The owner was recommended to change to a diet higher in animal protein and lower in carbohydrates. The owner stated that the after two weeks, the dog was calmer and began learning at an increased pace.

What are Carbohydrates?

Carbohydrates primarily come from plants although milk products also contain carbohydrates. Simple carbohydrates have only one or two units of sugar and are from grains such as corn, wheat, rice, oats, barley, and millet. Complex carbohydrates have more than two units of sugar hooked together and are found in potatoes, beans, as well as many other vegetables and fruits.

Carbohydrates provide the body with energy and are usually the first source of energy available to the body. Proteins and fats can also provide energy but carbohydrates are called upon first.

Carbohydrates also provide important dietary fiber which helps the digestive system function properly

There is, however, much written on the relationship between carbohydrates and children. Drs. Richard F. Heller and Rachael F. Heller, noted carbohydrate researchers and authors of several books, including Carbohydrate Addicted Kids (Harper Perennial, NY, 1997) wrote in this book, “Carbohydrate addicted kids often experience one or more difficulties that fall into three main categories: Hyperactivity (including excessive running, inability to sit still and fidgeting); impulsivity; and inattention.” All of these sounded like the puppies we were seeing in class.

Dogs and Carbohydrates

Although many dogs will happily munch a carrot, or beg for a piece of apple, most dogs do not naturally eat most carbohydrates, especially cereal grains. As Wendy Volhard and Kerry Brown, DVM said in their book, The Holistic Guide for a Healthy Dog (Howell Book House, NY, 1995), “Think about the origin of the dog. It is unrecorded in history that wolves lit fires and cooked grains picked in the fields!”

In addition, dogs do not digest most cereal grain carbohydrates well. With people, digestion begins in the mouth, with chewing and with our saliva which contains the enzyme amylase. Dogs, however, do not have amylase in their saliva. In addition, dogs do not chew their food; they tear and gulp it and the food begins digestion in the stomach. Dogs also lack other enzymes required to adequately digest many carbohydrates. Because of this, digestion takes longer.

David Kronfeld, Ph.D., Dsc., MVSc., author of numerous papers on dog foods, takes a much stronger stand against carbohydrates in the canine diet than most other canine diet experts. Whereas many experts feel that carbohydrates should be limited (but not totally eliminated) to help stave off health threats such as obesity and diabetes, Dr. Kronfeld said, “Carbohydrates are most important for dogs in two situations: puppies just coming off mother’s milk and lactating bitches.“ He continues by saying that carbohydrates need not be supplied to adult dogs, even those working hard, as the liver is able to easily synthesize sufficient glucose for utilization by the body.

Attempting to Solve the Problem

I decided to follow William Campbell’s lead and after explaining my theories to puppy owners, I began recommending higher animal protein (not plant protein) foods with carbohydrates supplied by other than cereal grains – such as sweet potatoes, apples, bananas and other foods.

Finding commercial dog foods that fell within those parameters wasn’t difficult; there are several on the market that are of very good quality. The ones that have produced the best results and yet are of very good quality for the dog’s overall health include dehydrated foods made by The Honest Kitchen. For more information, go to http://www.thehonestkitchen.com. For more on pet foods and nutrition, go to www.amazon.com and pick up a copy of Liz Palika’s book,The Ultimate Pet Food Guide (see the link in the left hand column on this page).

Dog Food Labels Can Be Deceptive

We have been taught that ingredients on foods are listed in order of decreasing amounts. Therefore a dog food with the listings of beef, wheat, rice, wheat germ and corn should be primarily beef, right? Wrong! In all reality, it probably isn’t. Oh, there is more beef than wheat; but there is not more beef than all of the cereal grains combined. A label like that is probably a cereal based food (read carbohydrates) with some beef! This is why it is so important to read the ingredients AND find the percentages of protein and carbohydrates.

Once the puppies were completely switched over to the new food (taking a couple of weeks to do that), the difference was easily seen. In over 75% of the puppies, there was a notable change within two weeks. Puppies were able to sit still for training, were learning more easily, and their owners noted a ‘calmness’ in the puppy that hadn’t been there previously. Another 10% showed an improvement later – usually within a month. Only a few – about 15% – showed no change at all.

Although we were pleased to see that our recommendations were working, we have been very careful to stress to our training clients that we are NOT veterinarians. Nor are we dieticians or nutritionists (although I am studying towards that end). We make our recommendations solely on the sake of the research we have conducted, the research of others and upon the end results we have seen in our classes.

We have been following this program for several years now and have kept in touch with many of the puppies and their owners. Quite a few of these puppies are now certified therapy dogs, several are certified search and rescue dogs, and some are obedience and agility competition dogs. But most are simply well loved family pets. We have seen no adverse reaction to the food changes (as to overall health and growth) and no local veterinarians have reported any health problems.

Dog owners should keep in mind, though, that many factors can affect behavior – not just food. The dog’s breed (or mixtures of breeds) can certainly play a part in behavior. A Border Collie will be more active than a Mastiff; and a Yorkie will be more defiant than an Australian Shepherd. The dog’s environment plays a part in behavior, too; as does his state of health, age, socialization, training and the amount of exercise he gets. So food is just one part of the puzzle but it appears to be an important part of it.Many dog owners are increasingly interested in home cooked, home made, and raw food diets. All of these have the pros and cons, and both benefits and dangers to our dogs. For more on these subjects, go to Amazon.com and order a copy of my book, The Ultimate Pet Food Guide. I discuss not only these issues, but also commercial foods – pros and cons. There are also more than 50 recipes in the book for dogs and cats.

Note: After this article was published in DOG WORLD, I received emails and letters from both dog owners and veterinarians. Dog owners thanked me for either confirming what they had already suspected, or for the advice that they change their dog’s food. Many saw differences. Several veterinarians (from all over the US and Canada) contacted me, saying they had been recommending these changes to their clients for years.

Originally published in DOG WORLD magazine in June 2006