My publisher, Dogwise, informed me last week that my book “Dog Food Logic: Making Smart Decisions for your Dog in an Age of Too Many Choices” has won the Dog Writer’s Association of America’s Maxwell Award for Best Health Care Book of 2014! For more information about “Dog Food Logic” and about my newest book “Beware the Straw Man” click the links below.
Said no dog. Ever.
This is how dogs more likely consider the possibility of being overweight:
Most owners are aware that it is our responsibility to keep our dogs at a healthy body weight and in good condition. We all know this, right?
Perhaps not. A few statistics:
- Obesity continues to be the number one nutritional problem in pet dogs in the United States.
- According to the Association of Pet Obesity Prevention (APOP), veterinarians classified 53 percent of their canine patients as either overweight or obese.
- In the same survey, only 22 percent of the owners identified their dog as being overweight.
- APOP founder Dr. Ernie Ward refers to this cognitive disconnect as the “fat pet gap”. He suggests that American dog owners’ perceptions of what is normal in their dogs has been gradually distorted, leading to the perception that an overweight body type is normal.
Why the Disconnect? A common theory used to explain the mismatch between what owners perceive and what their dog actually looks like is that owners simply have not been taught how to recognize a fat dog and lack the knowledge to differentiate between a dog who is at ideal weight versus one who is slightly (or more) overweight. In an attempt to counteract this problem, pet food companies created Body Condition Scores. These are standardized five to 9-point visual scales designed to help owners and veterinarians correctly assess a dog’s body condition. Here are two examples:
Problem solved? These scales have been around for more than 15 years. Yet, our dogs are still fat. Perhaps the scales are not being used? Are they difficult to understand? Recently a group of researchers asked the question: “If we give dog owners a BCS tool, show them how to use it, and then ask them to evaluate their own dog using the tool, will their assessments improve?” Their hypothesis was optimistic. They believed this would do the trick.
The Study: This was a pre-test/post-test study design and included a group of 110 owners and their dogs (1). In the pre-test portion of the study, the owner was asked to assess their dog’s body condition. No guidance was provided and the owner was required to select the word that best described their dog from a set of five terms; very thin, thin, ideal weight, overweight, or markedly obese. Following this assessment, the owner was provided with a five-point BCS chart that used the same five descriptors along with visual silhouettes and descriptions. They were given instructions of how to use the chart and were then asked to assess their dog a second time. The investigating veterinarian also assessed the dog using the BCS chart and physical examination.
Results: Several interesting (and surprising) results were reported:
- Prior to using the BCS chart, 2/3 of the owners (66 %) incorrectly assessed their dog’s body condition. The majority underestimated body condition, believing their overweight dog to be at or near his or her ideal weight. These results are consistent with those reported by other researchers and with the APOP survey.
- Following training with the BCS tool, these misperceptions persisted, showing virtually no change; 65 % were incorrect and only 15 % of owners changed their original score (some up/some down, and some from correct to incorrect!). The majority of owners continued to see their plump dog as being at his or her optimal weight.
- Here is where things get really weird.
- When queried, the majority of owners (77 %) stated that they believed that using the BCS chart had significantly improved their ability to estimate their dog’s body condition (huh?). This statement was made despite the fact that only 17 owners changed their scores after they learned to use the chart.
- And, those who believed the chart had helped them fared no better in post-test success than the those who believed that the chart did not help them.
Take Away for Dog Folks: This study confirms what several other researchers have reported and what the APOP statistics tell us; dog owners tend to underestimate their dog’s weight and body condition, seeing a dog who is overweight as ideal. It also goes an important step further. Even when owners are shown how to identify an overweight dog, they are literally blind to seeing the evidence in their own dog. We still get it wrong. Why is this happening? There are a few possible reasons:
- Fido is not fat; he just has big bones: Resistance to seeing one’s own dog as overweight may be a form of denial, similar to the well-documented misperception that many parents have regarding their child’s weight. Because being overweight is viewed negatively by others, is associated with well-known health risks, and may be perceived as reflecting badly upon a dog owner’s ability to care properly for their dog, denial may be quite an attractive alternative to the truth.
- Confirmation bias: In this pre-test/post-test situation, people may have resisted changing their scores following training simply because, well, people hate to be proven wrong. If an owner had preconceived beliefs about his dog’s weight and initially assigned a moderate score, he might subsequently (and unconsciously) use the BCS chart to confirm that belief, however misguided it was.
- Food is love: There are data from other studies showing that a substantial number of owners admit that they are unwilling to deny food to their dog even when they know the dog is overweight because they see feeding as an important outlet for love and nurturing (2). Similarly, owners tend to resist changing their feeding habits with their dogs even when aware of the adverse health effects of being overweight (3).
Soap Box Time: The results of this study are not encouraging and suggest that we have a long way to go regarding our ability to prevent and reduce overweight conditions in dogs. If you are a trainer, doggy day care owner, groomer, veterinarian, veterinary technician, or other pet professional who works daily with dog owners and their dogs, perhaps it is time for a little “tough love”. Post a BCS chart in your facility, have a weight scale handy, and don’t be afraid to use them. Call the fat dogs fat…….nicely of course and with great respect for their owners (the dogs won’t care; they will be proud). Help owners to face reality. Provide guidelines to help dogs to trim down, encourage exercise for both the dog’s body and mind, and help people to understand that keeping a dog trim is one of the best ways that we can support their health and demonstrate our love.
- Eastland-Jones RC, German AJ, Holden SL, Biourge V, Pickavance LC. Owner misperception of canine body condition persists despite use of a body condition score chart. Journal of Nutritional Science 2014; 3:e45;1-5.
- Kienzle E, Bergler R, Mandernach A. A comparison of the feeding behavior and the human-animal relationship in owners of normal and obese dogs. Journal of Nutrition 1998; 128:2779S-2782S.
- Bland IM, Guthrie-Jones A, Taylor RD. Dog obesity: Owner attitudes and behavior. Preventive Veterinary Medicine 2009; 92:333-340.
What I mean of course, is “What’s in your dog’s food?”
When asked this question, most owners read the list of ingredients found on their food’s label. By law, pet food ingredients must be reported in descending order of preponderance by weight at the time of processing. This means that ingredients that are found first in the list are present in greatest abundance in the food.
There are a number of limitations regarding the type of information that a pet food ingredient list provides to consumers; most of these are detailed in my book Dog Food Logic. However, until recently, it was generally presumed that misrepresenting food ingredients, for example listing an ingredient that is not actually present in the food or failing to identify others, was not one of those limitations. Unfortunately, such a presumption may be ill-founded.
Several research studies published in the scientific literature over the past four years have shown that at least some brands of commercial dog foods have ingredient lists that do not always conform to what is actually in the food.
Study 1: Four brands of dry dog food that are marketed as novel protein source diets containing venison were tested for the presence of other protein sources (1). Of the four products, two listed chicken and one listed rice protein in addition to venison on their label ingredient panel. Results: Of the four foods, three tested positive for the presence of soy protein and one tested positive for the presence of beef protein. In all of these cases, neither beef nor soy products were reported in the product’s ingredient list. (It is interesting and somewhat ironic to note that one of the foods that tested positive for soy protein carried a front label claim stating “No Soy!”).
Study 2: The same team of researchers tested four retail dry dog foods that carried a “No Soy” label claim and seven therapeutic dry foods marketed to veterinarians for use in diagnosing soy allergies in dogs (2). Results: Soy protein was detected in three of the four retail brands. Of the seven veterinary-prescribed foods, four were found to contain low levels of soy protein.
Study 3: Eleven limited ingredient diets (LIDs) and one veterinary-prescribed hydrolyzed protein food were tested for the presence of animal origin ingredients not reported on their ingredient label (3). This study used DNA analysis and microscopic analysis of food particles that allowed the distinction between mammal, fish, and bird tissues. Results: Of the 12 products, the species of animal identified by microscopic and DNA analysis matched the food label’s ingredient list in only two. In the remaining 10 products, bone tissue fragments from one or more unreported animal source proteins were present.
Study 4: Most recently, a comprehensive study published in the journal Food Control examined the content of 52 brands of commercial dog and cat food using DNA analysis. Results: Of the 52 products, 31 (60 %) had no labeling violations, meaning that the protein ingredients that were reported in the ingredient list completely matched the sources that were identified via DNA analysis. However, 21 brands (40 %) contained protein sources that were not listed on the ingredient list or in one case, a protein source that could not be identified. In three of these products, the protein source listed on the ingredient panel was entirely absent from the food. Chicken was the most commonly undeclared protein source in the mislabeled foods. This is not surprising because chicken is generally the least expensive source of animal protein in pet foods. Mislabeling was also more frequently observed in canned (wet) pet foods than in dry pet foods. The presence of goat meat (yes, you read that correctly) was found in 9 products. Seven of these identified another animal species source such as chicken or beef on their label and did not include the more generic “meat” term nor (obviously) “goat meat” as an ingredient.
Take Away for Dog Folks: The authors of the first three papers wrote that their objectives were to examine LIDs for the presence of undeclared protein ingredients. Their concern was the increased use of these foods by owners and some veterinarians to diagnose food-related allergies in dogs. If you are not familiar with it, the standard diagnostic approach when food allergy is suspected is to feed a food that contains a single and novel (or hydrolyzed) protein source to the dog for 8 to 10 weeks. This is called an elimination diet and its purpose is to prevent exposure to all potential food allergens. If a dog’s signs diminish, the elimination diet trial is considered positive for adverse food reaction (food allergy) and an attempt is made to identify protein sources that the dog can tolerate. The scientists’ concern was that owners were unwittingly using the LIDs as an alternative to the more expensive and supposedly better controlled veterinary-prescribed foods. The expectation was that the therapeutic foods would contain only what their labels claimed, while the retail LIDs would be contaminated with other ingredients. What they found however, was that both retail foods and veterinary-prescribed foods have the potential to be mislabeled. (Oops).
Regardless of results not always showing what one expects, there are several important issues that these studies expose:
- Intentional or accidental? The analytical tests used in these studies are able to detect very small quantities of undeclared protein sources. Therefore, a positive result does not necessarily mean that the source was contributing a large proportion of the food’s protein. It only means that an undeclared protein source was present. This might occur accidentally as a result of ingredient cross-contamination during transportation, via airborne particle transfer in the manufacturing plant, or through the use of equipment that was not thoroughly cleaned between production runs. Regardless of intent, these causes are still problems and should be addressed in good manufacturing practice and quality control procedures. Alternatively, the identification of chicken as the most frequently undeclared animal protein source certainly suggests the potential for intentional substitution and mislabeling, seeing that chicken is less expensive than the ingredients that it augmented or replaced. Because these studies did not investigate the quantities of undeclared ingredients or whether or not their presence was intentional, these are questions that still need to be answered.
- Diagnosing/managing allergic dogs: For those who live with dogs suspected of having a food allergy, these results are bad news regardless of knowing quantities or intent. Although the concentration of a food allergen that is needed to trigger an allergic response in dogs is not known, it is expected to be similar to that in people – very low. These studies suggest that feeding a veterinary-prescribed elimination diet may not be a guarantee that the dog is not exposed to a suspected allergen such as soy. In addition, feeding a dog a retail brand LID may not be an effective approach even when food allergens have been identified. For these reasons, some veterinarians and nutritionists recommend feeding a homemade elimination diet for the diagnosis of food allergies in dogs. Once the allergenic protein is identified, extreme care will be needed during food selection.
- Trust: Last, but certainly not least, are the issues of food mislabeling, manufacturing integrity and consumer trust. The cases reported in the most recent study, in which listed ingredients were completely absent from some foods and were substituted with other protein ingredients, are in clear violation of AAFCO labeling regulations. The researchers of that study had purchased the sample foods from retail vendors, which indicates that these violations are occurring without detection. What is not known is whether ingredient substitutions, additions, and mislabeling are intentional or accidental or where within the production chain these adulterations are taking place. What does seem clear however, is that consumers cannot always trust the ingredient list to represent only and all ingredients that are present in the food.
What is a dog person to do?? Remember that a substantial proportion of products that were tested in these studies contained all and only those protein ingredients that their labels reported. They were not mislabeled. If you feed commercial dog food, seek out reputable manufacturers. These are the producers who provide ingredient source information, manufacturing details, safety records, and detailed product information to their consumers. Moreover, ask questions, request information, demand transparency and be a critical thinker (and consumer) for your dog so that you have a better chance of knowing what is in YOUR (dog’s) food.
- Raditic DM, Remillard RL, Tater KC. ELISA testing for common food antigens in four dry dog foods used in dietary elimination trials. Journal of Animal Physiology and Animal Nutrition 2010; 95:90-97.
- Willis-Mahn C, Remillard R, Tater K. ELISA testing for soy antigens in dry dog foods used in dietary elimination trials. Journal of the American Animal Hospital Association 2014; 50:383-389.
- Ricci R, Granato A, Vascellari M, Boscarato M, Palagiano C, Andrighetto I, Diez M, Mutinelli F. Identificatin of undeclared sources of animal origin in canine dry foods used in dietary elimination trials. Journal of Animal Physiology and Animal Nutrition 2013; 97:32-38.
- Okuma TA, Hellberg RS. Identification of meat species in pet foods using a real-time polymerase chain reaction (PCR) assay. Food Control2015; 50:9-17.
Over the last few years, the sale of dog foods that carry a claim of natural, either embedded into their brand name or proclaimed on their front label, has exploded. According to the marketing research firm Packaged Facts, natural foods are currently the fastest growing segment of the U.S. pet food market. The sale of foods that are marketed in this way doubled between 2008 and 2012 and accounted for almost 80 percent of all new products introduced between January and August of 2014. Natural pet food sales dollars during the same period exceeded 3 billion dollars, making up two-thirds of total pet food sales.
So, what is all of the fuss about? Does a claim of “natural” mean anything for your dog or is it just one more marketing gimmick?
What natural is: The Association of American Feed Control Officials (AAFCO), the organization that sets pet food ingredient and labeling definitions, states that a pet food manufacturer can include the word natural in a product’s brand name or as a label claim if the food has been preserved using only non-synthetic (i.e. naturally-derived) preservatives. This means that the food cannot include artificially produced compounds such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tert-butyl hydroquinone (TBHQ), or ethoxyquin. Instead, naturally-derived preservatives such as tocopherols (vitamin E), ascorbic acid (vitamin C), citric acid, and rosemary extract are used. In today’s pet food market, this is not a high bar to clear. Starting in the 1980’s, consumer pressure to eliminate the use of ethoxyquin in pet foods was followed by a general trend away from artificial preservatives. Today almost all pet food manufacturers produce at least one product line of foods that are preserved without synthetic compounds and legally carry the “All Natural” claim.
In practice: AAFCO’s definition of “natural” is so broad that it includes nearly every single type of pet food ingredient that is currently included in commercial pet foods, with the exception of chemically synthesized vitamins and minerals. And even with these, there is a loop-hole. A manufacturer that includes these items can still use the natural moniker provided the statement “with added vitamins and minerals” is tacked onto the natural label claim.
What natural is not: A pet food label claim of natural does not signify anything about a food’s quality, the source or type of ingredients that it includes, the company’s manufacturing practices, or the food’s safety record. Neither does the appearance of the word natural signify that a food is organic, that it contains no GMO ingredients, is made from human-grade or high quality ingredients, or does not contain by-products. The bottom line is that other than assuring the owner that the food does not contain synthetic preservatives, a label claim of “natural” is meaningless and provides no information that helps to differentiate among foods in terms of their ingredients, quality, digestibility, manufacturing practices or food safety.
Natural vs. organic: There is however an important distinction between the terms natural and organic. According to the USDA’s National Organic Standards Board, a food can be labeled organic if the plant ingredients that are included were grown without pesticides, artificial or sewage sludge fertilizers, or irradiation and exclude genetically modified organisms (GMOs). Animal-source ingredients must come from animals that were raised exclusively on organic feed, were not treated with hormones or antibiotics, and were housed/fed according to an agreed upon welfare standard. However, these requirements were developed for human foods and the National Organic Program (NOP) lacks the legal authority to regulate organic label claims on pet food. Pet food companies can voluntarily choose to meet the NOP standards, apply for NOP certification, and if accepted can use the USDA Organic seal. However, because certification is optional, a pet food company’s use of certified organic ingredients does not mean that the product itself is certified organic via USDA standards. AFFCO has not yet developed a regulation for organic pet foods and recommends that pet food companies attempt to follow the USDA organic food regulations in their labeling practices. However, companies are not required to do so. If a company chooses to follow the guidelines of the National Organic Program (NOP), you should be able to tell by reading their claim and the ingredients list. If the label states “100 Percent Organic“, every single ingredient must be organic. Foods labeled simply “Organic” must include at least 95 percent organically produced ingredients. Below this level is the label claim “Made with Organic Ingredients”, for which at least 70 percent of the product’s ingredients are organic.
Why natural? Oddly enough, despite the fact that the term organic is more narrowly defined and better regulated than the term natural, it is the natural foods segment and not organic pet foods that are taking off in sales. A recent marketing research study examined these differences (1).
The Study: Marketing researchers at New Mexico State University surveyed a group of 661 U.S. dog owners regarding their pet food choices. The researchers used a research methodology called “discrete choice analysis” in which they presented participants with a panel of dog foods that varied in key attributes such as price, ingredient type, label claims, and package size and asked them to identify the food that they would choose for their dog. The objectives of the study were to test the effects of label claims such as “Veterinarian Recommended“, “Natural” and “Organic“, as well as package size, life stage formulation, and price upon dog owner preferences. Because a primary goal was to study perceptions of natural pet foods, the participants were provided with the AAFCO’s definition of the term natural and the USDA’s definition of the term organic prior to starting the survey.
Results: Of the five primary dog food attributes that were studied, the price of the food was found to be the most important determinant of choice. U.S. dog owners were consistently interested in finding the least expensive food. Following product cost, owners focused most intently upon whether or not the food’s ingredients were promoted as being natural or organic. When these two ingredient types were compared, dog owners were willing to pay the highest (premium) price for a dog food containing a claim of natural ingredients, more so even than for a food stating that it contained organic ingredients. Other attributes such as being recommended by a veterinarian, life stage formulation, and package size were less important. Following price point, the most important driver for choosing a dog food was seeing the word “Natural” somewhere on the label or in the brand name.
Take Away for Dog Folks: Perhaps the most important fact that dog owners should be aware of is that virtually anything goes when it comes to the “It’s Natural” claim on pet food labels. (This is also true of human foods, by the way). The only significant requirement is that a dog food labels as “All Natural” has is that it cannot contain artificial preservatives. That’s All.
However, even knowing the ridiculously broad definition of the term natural, people continued to attribute great value to the term and showed that they were willing to pay a premium price to see it on their dog’s food label. In fact, this study showed that owners were willing to pay more for natural ingredients than for organic ingredients despite learning just minutes earlier about the clear differences between the two terms and the stricter guidelines for and regulation of organic foods. Make no doubt about it; this distinction is a win-win for pet food manufacturers because the cost difference between making an “All Natural” pet food claim (that means nothing) and an “Organic” claim that (though optional) is associated with set guidelines for ingredient production and sourcing, is substantial. Expect to see even more of the word natural on pet food shelves in the future.
And train yourself to ignore that word.
Pet food claims for providing superior nutrition, for promoting health, or for being safer do not follow from a claim of naturalness without evidence of such benefit. And, this is especially true when the word means nothing at all in the first place.
1. Simonsen JE, Fasenko GM, Lillywhite JM. The value-added dog food market: Do dog owners prefer natural or organic dog foods? Journal of Agricultural Science 2014; 6:86-97.
“Beware the Straw Man: The Science Dog Explores Dog Training Fact & Fiction” is now available! Click on the image below for more information and to order.
Book summary: The Science Dog (aka Linda Case) takes a skeptic’s look at many commonly held beliefs about dog behavior and training. Each of the book’s 32 essays explores a question posed by leading researchers and provides detailed and thought-provoking analysis of their findings. Learn how dogs react to different training methods, discover the pitfalls associated with the use of extinction, and read about new studies that evaluate programs that communities use to keep children safe from dog bites. Other essays explore owners’ ability to understand their dog’s emotions, how people perceive and train small dogs, and if standard behavior tests used by animal shelters to assess dogs’ adoptability hold up under scrutiny. Whether you are a professional trainer, work with dogs in shelters or rescue groups, own a dog-related business or train your dog for fun, the information provided in “Beware the Straw Man” will be of interest and of value to you. Be forewarned though; this book does not provide the reader with pat answers. Rather it presents the current state of the science of dog training and encourages you to decide for yourself how to proceed.
When I was in graduate school, a fellow student recommended a book called The Structure of Scientific Revolutions by Thomas Kuhn. Published in 1962, it was already considered a classic in the philosophy of science by the 1980’s. Kuhn is responsible for defining and popularizing the concept of “paradigm shifts.” He explains that historically, scientific advancement has occurred as a series of relatively uneventful periods punctuated by intellectually abrupt “revolutions.” These are discoveries that are so new and unexpected that they change the entire way in which we do science, think about a topic, or even live our lives. Once accepted, these new concepts completely replace those that preceded them.
Paradigm Shifts: A paradigm shift is a change from one way of thinking to another; a new way of looking at an old problem. These shifts do not just happen, but rather are driven by people of great minds or by events of great import. For example, the development of agriculture changed humans from nomadic hunter-gatherers to sedentary community builders, and for better or for worse, allowed us to populate and dominate the entire planet. Similarly, Darwin’s theory of evolution changed not only how we looked at all other species on the planet, but (with some continuing resistance) how we look upon being human itself. Paradigm shifts also can be caused by new inventions. The invention of the printing press in the 1400’s led to the unprecedented preservation and distribution of knowledge and had a major role in the scientific revolution. In our own time, the introduction of the personal computer and the internet have had cultural ramifications that have impacted our personal and professional lives in ways that could never have been anticipated. These transformations all involve a replacement of old belief systems or way of doing things with an entirely new paradigm.
At the risk of over-dramatization, it appears that we are in the middle of a paradigm shift today that affects how we think about commercial pet foods and how best to feed our dogs. Although not a life-changing event for most people, or even perhaps not for most dog people, the changes that we are seeing in the pet food industry and among owner attitudes during the last seven years are unprecedented and certainly worth examining.
If you remember, the pet food industry was literally “born” in the early 1960’s as a consequence of the development of the extrusion process. Producing dry foods that provided complete nutrition, stored well and were convenient allowed dog owners to feed their dogs a single product for a relatively low price and to feel good while doing it.
Pet Food Choice Explodes: Starting in the mid 1980’s, research that studied the nutrient needs of dogs increased dramatically both at universities and within the private sector (pet food companies). This expansion occurred in large part because of the increasing importance that dogs had to our lives and the creation of an entire pet industry around that relationship. The advances in our understanding of canine nutrient needs and feeding behavior led to improvements in both the quality of many foods as well as an explosion in the number of brands and products that were available to dog owners.
By the new millennium, more than 90 percent of Americans were feeding a commercial dry (extruded) dog food to their dog and the explosion of life stage and life style foods has occurred almost exclusively within the extruded dry product segment. In addition to puppy and adult foods, we saw the development of products that target different adult sizes, activity levels, breeds, and health conditions. The variety of ingredients included in foods has similarly expanded, with the inclusion of new protein sources, grains (or no grains), types of fat and “functional” nutrients.
On the business side of things, the 1990’s and early 2000’s witnessed unprecedented growth in sales, followed by an epidemic of pet food company mergers and acquisitions. Small, privately owned pet food companies and their brands were gobbled up by a small handful of multi-national corporations. Over time, a single company became the owner not only of multiple brands of food but also numerous product lines within brands. By the early 2000’s, the majority of pet food brands sold in the United States were owned by the “five giants” of the pet food industry: Mars Petcare; Nestle-Purina PetCare; Colgate-Palmolive (owner of Hills); Procter and Gamble (P&G) Pet Care; and Del Monte Foods (recently renamed Big Heart). These five are now further consolidated down to four, when Mars purchased all of P&G’s pet food brands (Eukanuba, Iams and Natura) in April of 2014.
Pet Food Recall of 2007: The pet food paradigm shift that began in the early 2000’s accelerated tremendously in the spring of 2007. Sadly, this change came about not in response to a new discovery or an innovative type of pet food. Rather, it was set off by a massive pet food recall of unprecedented proportion that was caused by the intentional adulteration of a common food ingredient. The problem began when numerous dogs and cats started to become suddenly ill with renal failure, many never recovering. Although we now know that the company that was responsible, Menu Foods, had started to investigate the problem by early March, it took weeks of consumer complaints before a voluntary recall was initiated.
Worst nightmare: I remember that time well. My mom and I were attending a Canine Freestyle seminar together in St. Louis, Missouri. My mother, a trainer also, had been a board member of NADOI, and this seminar was held in conjunction with the organization’s annual meeting. During a seminar break, a long-time friend of my mother’s came and sat with us. She tearfully related that she had lost her beloved, young, German Shepherd earlier that week to renal disease, brought on by the tainted food. The most heart wrenching detail that I remember from that conversation was the distraught woman telling us of her continued attempts to entice her sick dog to eat the tainted food prior to knowing that it was the food that was actually causing her dog’s illness and eventual death. She spoke of warming the food and adding little tidbits to it, in an attempt to nurture her boy back to health. For me, and also for my mom and others in the room, this put a highly personal face on the daily statistics of pet illness and loss that we were reading about in the media. It is an understatement to say that losing a dog in such a way is every dog lover’s worst nightmare.
Over the following months and into early summer, the extent of the problem became appallingly evident. According to Dr. Stephen Sundlof, who was the head of the FDA’s Center of Veterinary Medicine at the time, the root cause of the contamination came from a switch in ingredient supplier. Buyers at Menu Foods had recently changed to a new supplier of wheat gluten, an ingredient that is included in canned foods as a thickening and binding agent. They had switched to an Arizona-based company called ChemNutra that was importing the ingredient from China. ChemNutra offered wheat gluten at a price that was about 30 percent lower than the cost of making (not selling) the ingredient in the US. It eventually became known that the Chinese suppliers were intentionally adding two non-food compounds, melamine and cyanuric acid, to wheat flour in order to make the flour appear to be the more expensive ingredient, wheat gluten. The adulteration had the effect of raising apparent protein levels of the ingredient in a deceptive manner, thus allowing the company to charge a higher price for what was actually a very low quality product. When present together in a pet food, we now know that melamine and cyanuric acid crystallize into a complex that accumulates in the kidney, leading to kidney damage and death. By the end of the disaster, it was estimated that over 5,000 pet food products had been tainted and were recalled and thousands of cats and dogs were sickened or killed.
This event, along with several subsequent pet food recalls for salmonella and aflatoxin (a toxin produced as a result of mold contamination to corn or wheat ingredients), led to changes in dog owners’ understanding of how pet food was made in the United States and to a dramatic shift in overall perceptions of the pet food industry. Perhaps the biggest shock to dog owners was the revelation that a single manufacturer, in this case Menu Foods Limited, was responsible for the production of dozens of brands of pet food that were owned by a wide variety of pet food companies, including the “big five” discussed earlier. As a result, different brands of foods were often produced using the same ingredients that originated from a common supplier. Perhaps even more significant was the realization that many pet food ingredients were sourced from outside of the United States, often in countries such as China, that had few or insufficient regulatory standards. Collectively, the truths that were revealed in the wake of the largest and most devastating pet food recall in history led to a rapid loss of consumer confidence and to increased skepticism of pet food companies and their products.
Other cultural shifts: While pet food recalls are dramatic and highly salient examples, several other cultural changes have also contributed to the pet food paradigm shift. It is common knowledge among people who work in the pet food industry that trends occurring in the human food industry quite reliably predict what we can expect to see occurring a few years later in the pet food industry. A recent example of this is the increased popularity of grain-free dog foods. These foods have their origins in the gluten-free and eventually grain-free movement in human diets. Grain-free brands of dog food were virtually non-existent before the year 2000. Today, almost every pet food company includes a dedicated grain-free brand or product line and some companies sell nothing but grain-free products. Similarly, as interest has grown about where and how our own food is produced, so too has there been increased interest in knowing more about the origin of the foods that we feed to our dogs and cats. Owners are increasingly sophisticated in their knowledge of foods and are more willing than ever before to scrutinize ingredients and label claims. Market segments that were once considered small and “niche” are now mainstream. Some owners wish to choose only foods that include organic ingredients, some eschew any foods that may contain genetically modified organisms, and others are switching to raw diets for their dogs. Many are concerned about the source of ingredients that go into foods as well as about who is producing their dog’s food. And, some are equally concerned with the environmental or animal welfare issues surrounding their own and their dogs’ foods or with consuming only foods that originate locally or regionally.
Not just your grandmother’s kibble anymore: So, let’s take a look at where exactly the pet food paradigm shift has led us. During the last 5 years, the pet food industry has witnessed an explosion of innovation and the development of new feeding philosophies and products. The development of extrusion in the early 1960’s almost instantaneously revolutionized the pet food industry, in large part because it led to the mass production of foods that were convenient, economical and that could be stored for long periods. Because the extrusion cooking process efficiently cooked starch and resulted in both increased digestibility and enhanced taste, dry foods contained a relatively high proportion of starch, plus various sources of animal- and/or plant-based proteins, animal or plant fats/oils, and vitamin/mineral “pre-mixes.” Convenience has been an attractive feature of extruded dry foods for many dog owners. Not only are these foods easy to store and feed, but they can now be purchased at every supermarket and big box outlet found in America’s shopping centers. Owners can purchase dry dog foods at grocery stores and mass market retailers such as Walmart, Target and even Walgreens. Together, these large retail sources are responsible for more than 70 percent of dog food sales. The pet superstores are responsible for about one-fifth of sales, followed distantly by small pet supply stores. Generally speaking, the perception of owners is that higher quality (i.e., premium) foods are available at pet supply stores, while the lower quality brands, which are also lower in cost, can be readily purchased at grocery store chains and mass market retailers. And generally speaking, these distinctions are true.
Notwithstanding the continued popularity of extruded foods, there are a number of completely new approaches to producing dog foods that have been developed in recent years as part of this paradigm shift and that provide a new set of choices to dog owners. Several of these approaches are used primarily to produce safe and storable raw foods, such as dehydration and freeze-drying. Others are a new approach to cooking and storing foods that contain ingredients other than those that are typically included in dry foods, in some cases, using ingredients that never leave the “edible” (USDA term for human grade foods) supply stream and so are classified as being produced from human grade ingredients and using human food production methods. While these foods still comprise a relatively small portion of the pet food market, I think they reflect the enhanced innovation and exploration into new possibilities that are coming about during the new age of pet foods as well as a response from dog owners who are demanding higher transparency from the pet food industry, along with higher quality and safer foods. The table below summarizes several of these approaches and provides a few brand examples for you to explore, should you so choose. (Note: The table does not contain a complete list of brands, but rather is intended to provide a randomly selected group of brands as examples).
|Food Form||Description||Brand Examples|
|Dehydrated||Dehydration involves removing most of the water from the mixed and ground raw ingredients. Gentle heating during dehydration kills microorganisms and partially cooks the food. Portions are rehydrated with warm water immediately prior to feeding.||The Honest Kitchen, Addiction, ZiWi Peak|
|Freeze-dried||Ingredients are mixed and then frozen under a vacuum to allow which allows product moisture to sublimate directly from the solid phase to the gas phase. Portions are rehydrated with warm water.||Stella & Chewy’s, Nutrisca, Orijen, SoJo|
|Refrigerated||Ingredients are gently cooked (not extruded), shaped into tubes or patties and refrigerated.||FreshPet|
|Frozen (Cooked)||Ingredients are gently cooked (not extruded), then frozen. May be complete and balanced or a pre-mix to which other ingredients are added at home||Evermore, Bil-Jac, Buddy’s Kitchen|
|Frozen (Raw)||Ingredients are combined, frozen, and packaged as rolls, or individual meal-size patties||Stella & Chewys, Nature’s Variety, Bravo!|
|Pre-mixes||A frozen or freeze-dried mix of either non-meat ingredients (to which the owner adds cooked or raw meat), or of meat ingredients (to which the owner adds vegetables, fruits, grains)||Fresh Oasis, SoJo, Bravo!|
|Raw Coated||Baked or extruded kibbles coated with freeze-dried (usually raw) ingredients||Great Life, Instinct (treats)|
NOTE: This essay was excerpted from my 2014 book “Dog Food Logic” (Dogwise Publishing, 2014), Chapter 7, pages 116-119. To continue reading and learn more, just click the image below. (Also available on Amazon). This essay kicks off a new series of Science Dog blogs that will examine new research in canine nutrition and feeding. Coming Soon – “The Nature of Natural”!
I grew up with a story-book grandmother. She was my mother’s mom, “Nana” to my sister and me. As required of all perfect grandmothers, Nana was a great cook and regularly expressed her love through sumptuous meals and comfort foods. Although she did not actually reside “over the valley and through the woods”, her home was definitely the place to be on all food-oriented holidays, including birthdays (cake!), Christmas (cookies!), and of course, the ultimate All-American food holiday, Thanksgiving (turkey!). Like many Americans on this day, my family gorged ourselves with all that Nana placed on her over-loaded dining room table – mashed potatoes, stuffing, butternut squash, warm rolls, salads, corn casserole, and of course, the mandatory roasted turkey. Following this annual feast, my sister and I would fall into food-induced stupors, sleeping off our over-indulgence for several hours before rousting ourselves to eat one more piece of pie.
A number of years later I learned that my post-feast drowsiness was (presumed to be) caused by to a specific nutrient in turkey. This theory, first put forth by a nutritionist, proposed that turkey meat contains unusually high levels of the amino acid, tryptophan. Once absorbed, tryptophan is used by the body to produce serotonin (a neurotransmitter) and melatonin (a hormone). The neurological pathway through which serotonin works has anti-anxiety and calming effects and melatonin helps to induce feelings of drowsiness (i.e. enhances sleep). Therefore, the theory goes, after consuming a high-protein meal, in particular one that is high in tryptophan, the body’s production of melatonin and serotonin increase, which in turn cause drowsiness, reduced anxiety and a calm state of mind. Presto – the post-turkey coma!
Tryptophan Takes Off: The tryptophan/turkey theory became so popular and widespread in the early 1980’s that nutrient supplement companies decided to by-pass the turkey part of the equation altogether and began producing and selling tryptophan supplements (L-tryptophan). These were initially promoted as sleep aids and to reduce signs of anxiety. However, as is the nature of these things, the promoted benefits of L-tryptophan rapidly expanded to include, among other things, claims that it would enhance athletic performance, cure facial pain, prevent premenstrual syndrome, and enhance attention in children with attention deficit-hyperactivity disorder. (My personal favorite was the promotion of L-tryptophan as a treatment for Tourette’s syndrome). L-tryptophan enjoyed a robust reputation as the nutrient for “all that ails ye’” until 1989, when it was found to be responsible for causing eosinophilia-myalgia in more than 5000 people, killing at least 37 and permanently disabling hundreds. The US Food and Drug Administration quickly banned its import and sale as a supplement. Although the problem was eventually traced to a contaminant in a supplement that was imported from a Japanese supply company (and not the L-tryptophan itself), the ban remained in effect until 2009. Today, L-tryptophan is once again available as a nutrient supplement but it has never regained its earlier popularity in the human supplements world.
What About Dogs? Given its history, it is odd that L-tryptophan was largely ignored by the dog world until a research paper published in 2000 suggested that feeding supplemental L-tryptophan might reduce dominance-related or territorial aggression in dogs (1).The researchers also studied dogs with problem excitability and hyperactivity, but found no effect of L-tryptophan on either of these behaviors. However, the paper led to the belief that tryptophan supplementation was an effective calming aid in dogs (which it definitely did not show in the study) and as an aid in reducing problem aggression. Today, a range of L-tryptophan supplements are marketed for reducing anxiety and inducing calmness in dogs. Interestingly, none are pure L-tryptophan, but rather also include other agents that are purported to have a calming effect on dogs, such as chamomile flower, passion flower, valerian root, or ginger.
What Does the Science Say? Does eating turkey or taking an L-tryptophan supplement reduce anxiety and induce calmness? And, can it be used as an effective nutrient supplement to reduce anxiety-related problem behaviors in dogs?
The Turkey Myth: It is a myth that consuming turkey induces drowsiness or reduces anxiety. The theory fails on several counts. First, turkey meat does not actually contain a uniquely high level of tryptophan. The amount of tryptophan it contains is similar to that found in other meats and is only half of the concentration found in some plant-source proteins, such as soy. (Do you get sleepy after gorging on tofu?).
Second, researchers have shown that the amount of tryptophan that is consumed after a normal high-protein meal, even one that contains a lot of tryptophan, does not come close to being high enough to cause significant changes in serotonin levels in the blood or in the synapses of neurons, where it matters the most. Third, to be converted into serotonin (and eventually into melatonin) tryptophan that is carried in the bloodstream following a meal must cross the blood-brain barrier and enter the brain. This barrier is quite selective and only accepts a certain number of amino acids of each type. Tryptophan is a very large molecule and competes with several other similar types of amino acids to make it across the barrier. Following a meal, especially if the meal is high in protein, tryptophan does increase in the blood and is pounding at the blood-barrier door for access. However, it is also competing with other amino acids that are also at high levels (turkey contains all of ‘em). As a result, very limited amounts of tryptophan make it into the brain for conversion following a meal that includes lots of other nutrients.
Why So Sleepy? The real explanation for the drowsiness and euphoria that we all feel following a great turkey dinner at Nana’s house is more likely to be caused by simply eating too much (which leads to reduced blood flow and oxygen to the brain as your body diverts resources to the mighty job at hand of digestion), imbibing in a bit of holiday (alcoholic) cheer, and possibly, eating a lot of high-carbohydrate foods such as potatoes, yams, and breads, which lead to a relatively wider fluctuation in circulating insulin levels. Whatever the cause, don’t blame the turkey or the tryptophan.
Tryptophan Flying Solo: The erroneous focus upon turkey did have some positive consequences in that it led to a closer look at tryptophan’s potential impact upon mental states and behavior when provided as a supplement. As a serotonin precursor, tryptophan (and its metabolite 5-hydroxytryptophan or 5-HTP) has been studied as either a replacement or an adjunct therapy for serotonin reuptake inhibitors (SRRIs), medications that are commonly used to treat depression in people and are sometimes prescribed as treatment for anxiety-related behaviors in dogs. Although limited work has been conducted regarding the effects of tryptophan supplementation in dogs, several informative papers did follow the initial dog study of 2000:
Tryptophan and anxiety: Researchers at Wageningen University in the Netherlands studied a group of 138 privately owned dogs with anxiety-related behavior problems (2). Study design: Half of the dogs were fed a standard dog food (control) and half were fed the same food, formulated to contain supplemental L-tryptophan. Neither the owners nor the researchers were privy to dogs’ assigned groups. In other words, this was a “double-blind, placebo-controlled study” (see my book “Dog Food Logic” for more about studies), the Gold Standard of research designs. Dogs were fed their assigned diet for 8 weeks, during which time the owners recorded behavior changes. At the end of the study, the researchers also performed a set of behavior evaluations to assess the dogs. Results: Although blood tryptophan levels increased significantly (by 37 %) in the dogs that were fed supplemental tryptophan, neither the owners nor the researchers observed any difference in behavior between the supplemented group of dogs and the control dogs. There were moderate changes in behavior over time in all of the dogs, but this change was attributed to a placebo effect. Overall, supplementation with L-tryptophan demonstrated no anxiety-reducing effects in the dogs enrolled in this study.
Tryptophan and abnormal-repetitive behaviors: This was another double-blind and placebo-controlled study (3). In addition, the researchers used a “cross-over” design in which half of the dogs are first fed the control and the other half are first fed the test diet for a period of time and are then all switched to the alternate diet for a second study period. This is a well-accepted study design that is helpful when a researcher has limited number of subjects and that helps to control for the placebo effect. A group of 29 dogs was identified, each presenting with a form of abnormal-repetitive behavior. These were: circling, anxiety-related lick granuloma, light chasing/shadow staring, or stool eating. (Note: One might question the inclusion of stool-eating in this study, since many pet professionals consider eating feces to be a form of scavenging behavior that is normal and common in the domestic dog). Dogs were treated for 2-week periods and the frequencies of their abnormal behaviors were recorded daily. Results: The researchers reported no effect of supplemental L-tryptophan on the frequency or intensity of abnormal-repetitive behaviors. Although the owners reported slight improvements over time, this occurred both when dogs were receiving the supplemental tryptophan and while they were eating the control diet (there is the insidious placebo effect again). Limitations of this study were that it was very short-term and it targeted uncommon behavior problems that are notoriously resistant to treatment. Still, this study did not provide any evidence to support a use of tryptophan supplementation for repetitive behavior problems in dogs. (So, to all you folks who live with poop-eaters – sorry, no easy answer here with L-tryptophan).
Tryptophan-enhanced diet and anxiety: Dogs with anxiety-related behavior problems were fed either a control food or the same food supplemented with L-tryptophan plus alpha-casozepine, a small peptide that originates from milk protein (4). This was a single-blind, cross-over study in which only dog owners were blinded to treatments. All of the dogs were first fed the control diet for 8 weeks and were all then switched to the test diet for a second 8-week period. Because the treatment group always followed the control in this study design, it is impossible to distinguish between a placebo effect and an actual diet effect in this study. (Note: This is a serious research design flaw that the study authors mention only briefly). Results: A small reduction in owner-scored anxiety-related behaviors was found for four of the five identified anxiety problems. However, in all of the cases, initial severity of the problems were rated as very low (~1 to 1.5 on a five-point scale in which a score of 0 denoted an absence of the problem and a score of 5 denoted its highest severity), and the change in score was numerically very small, though statistically significant. This is not surprising since there is not very much wiggle room between a score of 1 and a score of 0. Finally, given that the food was supplemented with both L-tryptophan and casozepine, conclusions cannot be made specifically about L-tryptophan.
Take-Away for Dog Folks
First, forget the turkey. While it can be a high-quality meat to feed to dogs (especially if you are selecting a food that includes human-grade meats or are cooking fresh for your dog), as a protein source turkey contains no more tryptophan than any other dietary protein. Feeding turkey to your dog will not promote calmness (unless of course, you allow him to stuff himself silly along with the rest of the family on Thanksgiving Day). Second, keep your skeptic cap firmly in place when considering the effectiveness of supplemental L-tryptophan or a tryptophan-enriched food as a treatment for anxiety-related problems. The early study in 2000 reported a modest effect in dogs with dominance-related aggression or territorial behaviors but found no effect in treating hyperactivity. Subsequently, two placebo-controlled studies reported no effect at all and the single study that reported a small degree of behavior change could not discount the possibility of a placebo effect.
Human nature encourages us to gravitate toward easy fixes for things that ail our dogs. Hearing about a nutrient supplement or a specially formulated food that proclaims to reduce anxiety and calm fearful dogs is powerful stuff for dog owners who are desperate to help their dogs. These types of claims are especially appealing because anxiety problems can have a terrible impact on a dog’s quality of life and are often challenging to treat using the standard (and proven) approach of behavior modification. An additional risk that must be mentioned regarding our inclination to gravitate toward unverified nutritional “cures” is that well-established approaches such as behavior modification may be postponed or rejected by an owner who instead opts for the supplement, wasting precious time that could actually help a dog in need. Until we have stronger scientific evidence that demonstrates a role for L-tryptophan in changing problem behavior in our dogs, my recommendation is to enjoy the turkey, but train the dog.
- DeNapoli JS, Dodman NH, Shuster L, et al. Effect of dietary protein content and tryptophan supplementation on dominance aggression, territorial aggression, and hyperactivity in dogs. J Amer Vet Med Assoc 2000; 217:504-508
- Bosch G, Beerda B, Beynen AC, et al. Dietary tryptophan supplementation in privately owned mildly anxious dogs. Appl Anim Behav Sci2009; 121:197-205
- Kaulfuss P, Hintze S, Wurbel H. Effect of tryptophan as a dietary supplement on dogs with abnormal-repetitive behaviours. Abstract. J Vet Behav 2009; 4:97.
- Kato M, Miyaji K, Ohtani N, Ohta M. Effects of prescription diet on dealing with stressful situations and performance of anxiety-related behaviors in privately owned anxious dogs. J Vet Behav 2012;7:21-26.
*A version of this article was published in the July 2014 issue of Whole Dog Journal.