“Only Have Eyes for You: Exploring Canine Research with The Science Dog” – Kindle Edition Now Available!

The Kindle edition of Only Have Eyes for You: Exploring Canine Research with The Science Dog” is now available! Click on the image below for more information and to order.

Book description:  In her second Science Dog book, Linda Case tackles commonly held beliefs about canine nutrition, pet foods, behavior, social cognition and training. Each of the book’s 32 chapters explores a current issue that is of interest to dog owners and pet professionals and presents the scientific evidence that supports or refutes commonly held claims and beliefs. Learn about pet food ingredients and research showing that what is on the label may not always be in the food, about measures of food quality (and what consumers may not know about the foods that they buy), and about the safety and digestibility of popular dog treats and chews. Other chapters review new information regarding how dogs communicate, factors that help or inhibit a dog’s ability to learn, and the effectiveness of different types of training. Find out if dogs are capable of “knowing what someone else knows”, if they feel empathy for their friends, if they bark for no reason, and if they are capable of feeling guilt following a misdeed. Learn more about breed stereotyping, factors that influence our perceptions of dogs, and which canine characteristics most influence our attraction to particular dogs. This newest Science Dog book has something for everyone who works with and trains dogs, as well as for those who simply love dogs and enjoy learning more about our canine best friends.

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New Book! “Only Have Eyes for You: Exploring Canine Research with The Science Dog”

Only Have Eyes for You: Exploring Canine Research with The Science Dog” (paperback version) is now available! Click on the image below for more information and to order. (Kindle version will be available soon!)

Book description:  In her second Science Dog book, Linda Case tackles commonly held beliefs about canine nutrition, pet foods, behavior, social cognition and training. Each of the book’s 32 chapters explores a current issue that is of interest to dog owners and pet professionals and presents the scientific evidence that supports or refutes commonly held claims and beliefs. Learn about pet food ingredients and research showing that what is on the label may not always be in the food, about measures of food quality (and what consumers may not know about the foods that they buy), and about the safety and digestibility of popular dog treats and chews. Other chapters review new information regarding how dogs communicate, factors that help or inhibit a dog’s ability to learn, and the effectiveness of different types of training. Find out if dogs are capable of “knowing what someone else knows”, if they feel empathy for their friends, if they bark for no reason, and if they are capable of feeling guilt following a misdeed. Learn more about breed stereotyping, factors that influence our perceptions of dogs, and which canine characteristics most influence our attraction to particular dogs. This newest Science Dog book has something for everyone who works with and trains dogs, as well as for those who simply love dogs and enjoy learning more about our canine best friends.

                                                                             ♥♥♥♥♥♥♥♥♥♥♥♥♥♥

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What’s in Your (Vegetarian) Food?

Here we go again.

It appears that there may be more than what dog owners expect to find in vegetarian dog food.

Hold the Spam, Please: Before all of the  “Dogs are Carnivores (and a pox on your mother if you think differently)” devotees begin posting comments (in all caps ) that dogs should NOT be fed a vegetarian diet in the first place, let me state that this is not what this blog piece is about. So please, don’t even start. The point of this essay is not to argue (again…..) whether or not dogs have an absolute requirement for meat in their diet (here’s a hint: They don’t). Rather, today we examine new information about undeclared ingredients that may be present in dog food and the mounting evidence of regulatory violations within the pet food industry.

In this newest pair of studies, a team of veterinary nutritionists at the University of California tested vegetarian pet foods for label compliance and ingredient content.  I have written about this before, and unfortunately once again, the news isn’t good.

25-Foods-That-Seem-Vegetarian-But-Arent

Label Compliance: In the first study, the researchers collected samples of 24 dog and cat food brands that carried a label claim of “vegetarian” (1). The majority of the foods were over-the-counter products purchased at a local pet supply store. Three products were veterinary therapeutic diets. Of the group of products, 19 were formulated for dogs or for dogs and cats, and five were formulated exclusively for cats.  Product labels were examined for their compliance with the Association of American Feed Control Official (AAFCO) model regulations, which are the basis for most state mandated pet food regulations. Pet food samples were also analyzed for total protein and essential amino acid content. Results: Of the 24 foods, only eight (33 %) were in complete compliance with AAFCO label regulations. This means that 16 brands (66 %) had one or more violations. The most common infractions were the omission of feeding instructions or caloric content, improperly reported guaranteed analysis panels, and mislabeled ingredient statements. Nutrient analysis showed that all but one of the foods met AAFCO’s minimum crude protein requirements. However, six brands had deficient levels of one or more of the essential amino acids. This means that while the total amount of protein that the food contained appeared to be sufficient, essential amino acid requirements, which are more important, were not always met.

Presence of Animal-Based Ingredients: In a second study, the same group of researchers tested 14 brands of vegetarian pet foods (2). They purchased each food on two occasions to obtain samples as duplicates from different manufacturing batches. Six were dry and eight were canned products. Samples were analyzed for the presence of mammalian DNA using an accepted laboratory technique called multiplex polymerase chain reaction (PCR). Since all 24 foods were marketed as vegetarian (and in some cases, as vegan), none included animal-based components in their list of ingredients. Results: All six of the dry (extruded) foods that were tested contained DNA from beef, pork or sheep and five of the six contained DNA from multiple animal species. These results were consistent across batches for all 7 products.  Only one of the 8 canned vegetarian foods contained animal DNA (beef) and this finding was not repeated in the second sample. In this study, the researchers also tested for the DNA of dogs, cats, goats, deer, horses, rats, mice and rabbits. DNA from these species was not detected in any of the samples. Similar to earlier studies that have found the DNA of undeclared meats in dog foods, the amount of animal-based ingredients in the foods could not be quantified. The researchers could not speculate whether the labeling violations were a result of deliberate adulteration or unintentional cross-contamination of vegetarian products with meat-containing foods produced at the same facility.

soapbox

Soap Box Time: The Federal Food, Drug and Cosmetic Act requires that all pet foods sold in the United States are safe, produced under sanitary conditions, contain no harmful substances, and are truthfully labeled (emphasis mine). Perhaps I am being picky, but labeling a food as vegetarian and then not ensuring that the food indeed lacks the meat of cows, pigs and sheep, seems to qualify as not being truthful. (Some might even call it lying, I suppose). Not only are such egregious errors in violation of both FDA and AAFCO regulations, but they seriously impact the trust that dog owners have in pet food manufacturers. And rightly so.

To date, the majority of pet owners in the US continue to feed dry, extruded food. Of the dry-type vegetarian foods tested in this study, all of them, 100 % were, in fact, not vegetarian at all. This leads one to ponder about other products on the market and whether it is more the norm than the exception for dry dog foods that are sold as vegetarian to be nothing of the sort. While the authors note that this was a small number of products and so do not represent all vegetarian foods, the fact that all of the foods failed their DNA tests is alarming.

What can you do as a dog owner? Contact the manufacturer of your food and ask them how they verify the integrity of their products, specifically, the ingredients that they include in their foods. If they are not forthcoming and transparent with their response, find another producer who is. The good news is that the pressure that research studies such as these place on pet food companies and upon the industry as a whole will hopefully encourage increased transparency and improved regulatory oversight – something that we are apparently in dire need of.

Cited Studies:

  1. Kanakubo K, Fascetti AJ, Larsen JA. Assessment of protein and amino acid concentrations and labeling adequacy of commercial vegetarian diets formulated for dogs and cats. Journal of the American Veterinary Medical Association 2015; 247:385-392.
  2. Kanakubo, K, Fascetti AJ, Larsen JA. Determination of mammalian deoxyribonucleic acid (DNA) in commercial vegetarian and vegan diets for dogs and cats. Animal Physiology and Animal Nutrition 2016;  doi: 10.1111/jpn.12506.

 

How Reactive is Your…….Lysine?

I imagine that the word “reactive” caused most readers to think of this:

reactive dog

REACTIVE DOG

However, what we will actually be talking about is this:

Lysine-zwitterion-2D

LYSINE – AN ESSENTIAL AMINO ACID

Yeah, not quite so dramatic, I admit. However, the reality is that the amount of  reactive lysine present in your dog’s food is much more likely to have an impact on his health and wellness than is the somewhat lower risk of meeting Mr. Crabby Pants pictured above.

The reason? Well,  its all about the protein quality of commercial dog foods –  the good, the bad, and the reactive.

Reactive lysine: Lysine is one of the 10 essential amino acids (the building blocks of proteins) that must be provided in a dog’s diet. The term essential means that dogs cannot produce these amino acids endogenously (in the body) and so they must be supplied by the protein in the food. Of the essential amino acids, lysine is rather unique in that it has a reactive amino group (the blue H3N+ in the graphic above). This group hangs out into space waving its H+ around, which is ready and able to engage and link up with other molecules. And, just as with reactive dogs, these encounters do not always end well.

When food proteins are subjected to heat treatment and other processing conditions, some of this lysine binds to certain sugars and amino acids. When this occurs, the modified form of lysine is not available, meaning that the dog is unable to use the lysine, even after it has been digested and absorbed into the body. Some of the altered lysine may be modified further to produce compounds called “advanced Maillard compounds“. Maillard products are actually quite well-known to most people – they cause the browning of the toast that you eat for breakfast, on the onions that you caramelize, and form the grill lines on your hamburger.

Maillard-reaction-graphic-062912

JUST TO BE CLEAR

Reactive lysine in dog foods: Tasty toast aside, for dogs and commercial dog foods, measures of the amount of reactive lysine and Maillard compounds provide an indication of a food’s protein quality. This goes above and beyond digestibility (which we discussed in an earlier blog, “Scoopin’ for Science“), because the amount of reactive lysine reflects the actual nutritive value of the protein once it has been digested and absorbed into the body.

Processing damages protein: The heat treatment that is used to produce commercial dog foods has many benefits – it functions to improve a food’s overall digestibility, enhances shelf life, and assures food safety. However, heat and mechanical processing can also result in damage to the food’s protein. The good news is that the degree of this damage can be measured using laboratory procedures that analyze reactive (available) lysine (RL) and total lysine (TL). A ratio is then calculated between these two values (RL:TL). A high ratio value reflects more reactive lysine, less protein damage and higher quality protein. Conversely, a low value signifies greater loss of lysine during processing, more damage to the protein, and lower quality.

Cool, right? Well, yeah. Really cool. Because measuring reactive lysine ratios provides us (dog folks) with an indication of how processing such as canning, extrusion, rendering, and even dehydration or freeze-drying, might damage food protein and reduce the overall quality and nutritional value of a dog food.

Too bad this information is never reported by pet food companies. (To date, they are not required to report any measures of food digestibility or protein quality to their consumers).

Even though pet food manufacturers are not reporting these values, a group of scientists have been.

science-header

The Study: Researchers with the Animal Nutrition Group at Wageningen University in The Netherlands have been examining reactive lysine content and Maillard reaction products in a variety of commercial pet foods. In a recent paper, they collected 67 different brands of dog and cat foods, formulated for different life stages (1). Lysine levels were measured for each, and RL:TL ratios were calculated. The researchers also compared available lysine levels in the foods to the minimum lysine requirements reported by the current NRC Nutrient Requirements for Dog and Cats.

Results: A wide range of RL:TL ratios were reported, suggesting that protein damage in commercial foods is highly variable and may not be dependent simply on the type of processing that is used:

  • Processing type vs. ingredients: Overall, as reflected by the RL:TL ratio, canned foods had less protein damage than extruded foods, which had less damage (surprisingly) than pelleted foods.  However, the range of values within processing type was very high with the three types of foods showing a lot of overlap. This suggested that source and type of ingredients may matter as much as or even more than processing type.
  • Ingredients: Many of the ingredients that are used to produce pelleted and extruded foods are pre-treated with heat, drying and grinding. For extruded foods, this refers primarily to the production of meat meals (see “What’s the Deal with Meals” for a complete discussion of protein meals). It is speculated that this processing and how well it is (or is not) controlled is the most important determinant of changes in protein quality.
  • Meeting lysine requirements: Of the foods that were examined in this study, up to 23 percent of a product’s lysine could be damaged and made unavailable to the dog. When these losses were considered while accounting for expected protein/lysine digestibility, some of the foods were expected to be at risk to not meet the minimum lysine requirement for growing dogs.

The authors conclude: “Ingredients and pet foods should be characterized with respect to their reactive lysine content and digestibility, to avoid limitations in the lysine supply to growing dogs” I would add to this that these measures should be available in some form to consumers, as a measure of the protein quality of the food that they are considering buying.

Detractors might argue that RL:TL ratio is “too complex” for consumers to process and understand. I disagree. A simple classification chart, such as “poor, moderate, and high” quality could be derived from the range of reactive lysine values that are reported. Knowing this information, along with the type and source of ingredients, would allow owners to make meaningful quality distinctions among foods.

soapbox

DRAGGIN’ OUT THE OL’ BOX

I have argued elsewhere that pet food producers should be required to provide digestibility information about their products, when requested. This is not too much to ask, seeing that manufacturer’s claims of “Complete and Balanced” promotes the feeding of their products as the sole source of nutrition to our dogs.  And now, according to the results of research coming from Wageningen University, there are additional measures of protein quality that can differentiate among poor, adequate and superior foods.

It is time to ask for more of pet food manufacturers. Measuring digestibility and reactive lysine levels of foods and ingredients provide measures of product quality that are directly pertinent to nutritive value and to our dogs’ health. Here is your chance, as your dog’s advocate, to be a bit reactive (no – PROACTIVE) with your pet food manufacturer…… Politely request this information about the products that you are buying – let me know what you hear back!

Proactive and Reactive handwritten on whiteboard isolatedCited Study: van Rooijen C, Bosch G, van der Poel AFB, Wierenga PA, Alexander L, Hendriks WH. Reactive lysine content in commercially available pet foods. Journal of Nutritional Science 2104; 3:e35:1-6.

 

Dog Food Marketing – Science Weighs In

Marketing researchers know a lot about advertising strategies that successfully increase sales. This is no less true for pet foods than it is for any other consumer goods. Some of the more obvious approaches to attracting dog owners to a particular brand are advertisements that appeal to our emotional attachment to dogs, capitalize on our desire for expert approval, or that exploit our fascination with the lives of celebrities.

Appeal to Emotion 3    Appeal to Authority 1

                    APPEAL TO EMOTIONS                                             APPEAL TO AUTHORITY

 

Appeal to Celebrity

APPEAL TO CELEBRITY

One of my personal favorites of the “I love celebrities” category is an ingenious brand of Nestle’-Purina’s in which the celebrity to whom the product refers, supposedly a famous chef, does not, um, actually exist…….

Chef Michael

The Ad: It’s not just dog food. It’s Chef Michael’s. Crafted with great care, attention to detail and inspiration from our executive chef”

The Disclaimer: In the spirit of full disclosure (and to avoid litigation), the company provides the following response to inquiries about the whereabouts of the personage who is Chef Michael: “Chef Michael is not a real person, but a reflection of the many people inspired to make mealtime special for their dogs”.  I dunno. I think I would still like to get the guy’s autograph.

So, pick your poison – there is a dog food advertising campaign out there designed to appeal to just about every dog owner demographic. And, even though each and every one of us will insist that these schemes do not work on us (and that we select a dog food based solely upon its nutrient content, ingredient quality and suitability for our dog, thank you very much), these campaigns do indeed work very well.

Marketing’s Holy Grail: One category of advertising claims that has been shown to work particularly well, increasing human and pet food sales more than any other, are health claims. Because of the cumulative effects of a series of three laws that were passed in the 1990’s, the regulatory oversight of health claims on foods has been drastically curtailed over the last 35 years. Over time, the loss of regulatory oversight over health claims in human foods has led to labels that look like this:

Health Claims Human Foods

Dog foods quickly followed suit.  And pet foods are no different. As it stands today, pet food companies may include general health claims on their labels with no legal obligation to substantiate those claims. In other words, they neither have to prove the claim nor provide any evidence supporting the claim to any regulatory agency. Marketers must simply word their brand name or advertisement carefully enough to prevent the FDA from considering it a drug claim (which are regulated).

The difference between a general health claim (allowed and no proof needed) and a drug claim (not allowed; regulated by FDA) for pet foods turns on just a few words and phrases, as shown in the table below from Dog Food Logic.

Claims Table

TABLE EXCERPTED FROM “DOG FOOD LOGIC“, by Linda P. Case, page 175

Here are a few product examples:

Skin Coat 3                 Skin Coat 5            Skin Coat 7                        Skin Coat 8

Might these health claims be confusing to pet owners? A recent study asked exactly that question. 

The Study: A group of researchers at Tufts University’s Cummings School of Veterinary Medicine examined the nutrient profiles and ingredients list of 24 brands of dog food that all were marketed for skin and coat health (1). The objective of their study was to identify consistencies (or inconsistencies) among different commercial products making claims of promoting skin and coat health in dogs.

Results: They examined 15 dry (extruded) foods and 9 canned foods, representing 11 different brand names. Here are their results:

  • Its all in the name: All 24 products included the terms skin, coat plus a descriptor of skin/coat health in their brand name. They also included additional health-related terms on their labels and on websites. The most commonly used were sensitive, skin sensitivities, digestive sensitivity, digestive health, and limited/unique ingredients.
  • Ingredients: If you had thought there would be a handful of specific ingredients that are known to be beneficial to skin and coat, think again. The protein sources in the 24 foods were all over the map and included chicken, fish, egg, venison, beef, pork, duck, lamb, soy, peas, and turkey. A similar cornucopia was found for carbohydrate sources, with rice, potato, wheat, oats,  barley,  millet, corn, quinoa and tapioca all making an appearance.
  • Not so special fatty acids: Thirteen of the 24 foods (54 %) identified fatty acids as nutrients that are important for skin and coat health. While this may be true for certain specific omega-6 and omega-3 fatty acids (and their ratios), 10 of the 13 foods did not identify these by name but instead used vague (and meaningless) terms such as “omega fatty acids” or “omega oils”. Less than a third of the foods provided information about the amount of any specific fatty acid in the food. When this information was provided, the range in EPA and DHA (two important omega-3 fatty acids) concentrations overlapped with those found in foods not labeled for skin/coat health.
  • More nothin’ special: The essential nutrient content and caloric density (number of calories per cup) of the 24 foods varied enormously and overlapped with other brands that are sold for adult dogs but which are not specifically marketed for skin health. (In other words, not to put too fine a point on it, there was nothing that was consistently special or unique about the nutrient content of these foods. Even omega-3 fatty acid concentrations were all over the map, making the claims of “Source of Omega-3 Fatty Acids” essentially useless to consumers).

Conclusions: The researchers were rather circumspect in their conclusions, stating that the wide variety of ingredients and large range in nutritional value of products marketed for skin and coat health make product selection for owners who are interested in these foods confusing. (Personally, I go further than “confusing”).

 

soapbox

OUT COMES THE OL’ BOX….

Up on My Soapbox: I could be wrong, but I rather doubt that a concerned owner, whose dog is experiencing skin or coat problems and who sees a food that is specifically labeled “Sensitive Skin“, stops and ponders: “Well, the company does not actually state outright that this food cures sensitive skin problems. Nor do they say that they have proven that the food supports healthy skin. Therefore, I know better than to expect this food to do much of anything at all to help my dog”.

I may be going out on a limb here, but I believe this owner is much more likely to be thinking “Oh, look! A food that is designed to help Muffin’s sensitive and itchy skin! I will give it a try because poor Muffin’s skin has been terribly bad lately. I bet this food can help her!”. Ka-ching. Another day, another unregulated and misleading pet food claim, another sale. Poor Muffin.

Take Away for Dog Folks: If your dog is continually or excessively itchy or has skin problems, please make a visit to your veterinarian, not to your local pet supply store. It is important to obtain an accurate diagnosis for skin problems because the majority of these are not related to food. Rather, the most common causes of excessively itchiness in dogs are allergies to environmental allergens such as house dust mites, pollens and molds or fleas. Only after these causes have been eliminated should food be looked at as a potential underlying cause. (Note – The diagnosis of food allergy can only be made through the use of an 8 to 10 week elimination feeding trial, which is a topic for another blog at another time).

(By the way, if you find Chef Michael, get an autograph for me).

Cited Reference: Johnson LN, Heintze CR, Linder DE, Freeman LM. Evaluation of marketing claims, ingredients, and nutrient profiles of over-the-counter diets marketed for skin and coat health of dogs. Journal of the American Veterinary Medical Association 2015; 246:1334-1338.

 

 

 

What’s the Deal with Meals?

 

 

nestle-purina logo            Versus 2              Blue Buffalo Logo

The Pet Food Wars: In May 2014, Nestlé-Purina, the largest producer of pet foods sold in the U.S., filed a lawsuit against Blue Buffalo, a competitor. Among other things, the lawsuit alleged that Blue Buffalo’s marketing claims—that their foods contained no by-product meals—were false and disparaging to other companies’ products. According to the report of a testing laboratory hired by Nestlé-Purina, at least a few varieties of Blue Buffalo dry extruded foods (kibble) did indeed contain poultry by-product meal, comprising as much as 25 percent of the meal in some of its products. As is the way of the modern pet food industry, within days, Blue Buffalo responded with a countersuit of its own, accusing Nestlé-Purina of defamation, unfair competition and false advertising.

Central to this public (dog) food fight was the belief, strongly promoted by Blue Buffalo, that chicken or poultry meals are of superior nutritional value to by-product meals, and that high-quality dog foods contain the former and reject the latter. (It is of interest to note that Nestlé-Purina sidestepped the nutrient quality issue altogether in their lawsuit. Rather, they contended that Blue Buffalo had falsely promoted itself as being completely transparent to its customers.)

keep-calm-and-deny-deny-deny-4

Deny, Deny, Deny: Initially, Blue Buffalo responded to the allegations with denial. Both companies launched public-relations campaigns that included strongly worded letters to consumers. However, in October, Blue Buffalo had to eat crow (meal?) when they announced that one of their suppliers, Texas-based Wilbur-Ellis, had mislabeled an ingredient, which resulted in the presence of poultry by-product meal in some of their foods. In the words of Blue Buffalo’s founder, Bill Bishop: “So, while their customers were ordering and paying for 100 percent chicken meal, at times they were receiving shipments that contained poultry by-product meal. As a result, we have stopped doing business with this plant.

What is the truth? Are by-product meals lower in quality when compared with meals? Should discerning dog owners avoid chicken or poultry by-product meal and choose only foods that contain chicken or poultry meal? And is this a reliable way to distinguish between high-quality dog foods and foods of lesser quality?

Perhaps the best place to start is with an understanding of what a “meal” actually s.

Meals – The Protein Ingredient: Every ingredient that goes into a dog food contains a unique set of essential nutrients that it contributes to the finished food. In commercially prepared dry (extruded) dog foods, various types of meals are used to provide protein. These are classified in several ways.

  1. Plant vs. Animal Source: Examples of commonly used plant-based protein meals are corn gluten meal, soybean meal and pea protein (or meal). In general, plant-based protein sources are an inexpensive source of protein and are found in foods marketed to pet owners interested in economy. The quality of these meals is moderate to low in terms of amino acid balance and digestibility, although several protein sources are used to ensure that all essential amino acid needs are met. Animal-source protein meals, on the other hand, vary tremendously in both source—animal species—and in quality measures such as digestibility, amino acid content and amino acid availability.
  2. Species vs Generic Group: Animal source protein meals may be provided as species-specific meals or as generic animal groups. Examples of species-specific meals are chicken, bison, beef, salmon, venison, turkey and lamb meals. Alternatively, these meals may be classified more largely as poultry (contains varying amounts of chicken, turkey or duck), fish (contains multiple fish species), or meat (contains varying amounts of pork, beef or sheep). When you see a named species as the major protein meal ingredient, it generally indicates that the food is of higher quality (or at least a better-regulated product). Ingredient supply companies are required to keep these ingredient streams separate and designated, which means that sources are not mixed and translates to a more uniform product and greater regulatory oversight. Conversely, the generic term used to describe a group of food animals means that the meal may contain a mixture of species with no guarantee of any particular animal species or proportions in a given product. At the production level, this also means that several ingredient streams are combined, with varying sources of origin, regulatory oversight and quality attributes.
  3. Meals vs. By-Product Meals: The term “by-product” is the designator receiving the most attention. It is important to know that on pet food labels, this term is only applied to chicken and poultry meal. And, the distinction is largely bureaucratic; the Association of American Feed Control Officials (AAFCO) sets the definitions for ingredient terms and they have not designated a by-product meal term for any other animal protein meal. The closest they’ve come is “meat” meals versus “meat and bone” meals; the latter contains bone, which can reduce its quality as a protein source. (More about the purported differences between chicken/poultry meal and by-product meal later).

Meals are Produced via Rendering: Rendering is a cooking process that converts slaughterhouse products that have been deemed unfit for human consumption into a form that is regulated as acceptable for use in pet foods. Generally, animal parts used for rendering are those not typically consumed in our Western diet: organ meats such as spleen, kidneys, liver; stomach and intestines; varying amounts of bone; and, in the case of poultry, necks, feet and heads. In addition to slaughterhouse waste, “spent” layer hens from the egg industry and food animals found to be too diseased or injured to pass inspection for use as human foods may also end up at the rendering plant. Classified during the slaughter process as “inedible,” these parts are redirected into an alternate supply stream and are handled, transported and processed differently than those intended for human consumption.

The Process: During the rendering process, the combined components are ground, mixed and heated to a high temperature (220° to 270° F), which cooks and sterilizes the mixture, effectively killing the microbes that are present. Sterilization is absolutely necessary because refrigeration is not required for the handling or transport of inedible foods. The resulting slurry is centrifuged at high-speed to remove lipids (fat). The removed fat is further processed and eventually is sold separately as chicken, poultry, or animal fat. The mixture that remains is dried and ground to a uniform particle size that ultimately has the appearance and texture of dry corn meal. Animal protein meals are very low in moisture and contain between 55 and 65 percent protein, making them a rich source of protein when included in a pet food.

Chicken Meal

THE END RESULT – CHICKEN MEAL

Why use Protein Meals? From a commercial perspective, meals are well suited for use in dry foods because they can be stored and transported easily, and have the low moisture content necessary for extrusion processing. By comparison, high-moisture protein ingredients, such as “fresh” chicken (or other meat), contribute only small amounts of protein by weight to the end product because the water is cooked off during the extrusion process. These ingredients may be listed first on a food’s ingredient list simply because they contain more than 65 percent water, and ingredients must be listed in predominance by weight at the time of processing. In reality, it is the dried meals, usually found within the first three to five ingredients on the list, that provide the bulk of dietary protein in dry dog foods.

It Aint’ your Grandma’s Roast Chicken: According to AAFCO, the term “meal” refers to the “dry, rendered product from a combination of clean flesh and skin with or without accompanying bone, derived from the parts of whole carcasses of [chicken/poultry], exclusive of feathers, heads, feet and entrails.” (1)  Although this definition seems to suggest that meals are produced from the same parts of the chicken that make it to the supermarket for human consumption, this is simply not true. As mentioned previously, animal protein meals are produced from slaughterhouse waste and other food animals that are deemed “not for human consumption” (i.e., inedible).

In the case of chicken, these waste products are predominantly “chicken frames,” the remainder of the chicken’s body after the parts destined for human consumption have been removed. More than 70 percent of a broiler chicken ends up in the supermarket, leaving about 30 percent in the frame, which is made up of a bit of muscle meat plus a lot of connective tissue and bone.

Chicken Frames

CHICKEN FRAMES

None of the animal protein meals that are used in the production of dry dog foods are produced from edible (human grade) meats. This is because rendering plants are in the business of taking inedible animal parts and converting them into a form that can be fed to non-human animals. Chicken meal comes from chicken frames that are designated as not for human consumption, not from supermarket chicken.

        Chicken Meal          Unequal Sign       Fresh Chicken             

The Deal (with By-Product Meal): By-product meals are composed of exactly the same chicken components found in meals, but by-product meals may also contain varying quantities of heads, feet and viscera (guts). Therefore, the difference between a chicken (or poultry) meal and its respective by-product meal is the inclusion of heads and necks, feet, and guts (viscera) in the latter and the exclusion of those body parts from the former. On the face of it, this appears to be an obvious quality distinction. After all, any product that has heads, feet and guts in it not only sounds yucky, but certainly must also be of poor quality, right?

Well … it depends.

Given this definition, the general (and understandable) perception is that meals will be of higher quality than by-product meals. This is clearly the conclusion that Blue Buffalo and other pet food companies that make “No By-Products!” claims on their labels are banking on. However, consistent and substantial quality differences between the two ingredient types are not reported. The fact is that the inclusion of additional body parts (heads, feet and guts) in by-product meals can reduce, maintain or improve the quality of a meal (2).

Beaks, Feets and Guts, Oh My! These three additional parts, although certainly not very appetizing to most people, have varying nutritional value as food ingredients. First, the protein quality of viscera (internal organs and intestinal contents) is similar to that of chicken flesh components included in very high-quality chicken meals (and to what humans consume in a chicken dinner). In other words, including organ meats and intestinal contents in a by-product meal does not negatively affect the meal’s protein quality and may even improve it in a poor or average quality meal. Second, the inclusion of chicken heads in the mix results in a slight reduction in nutritional quality. This is because chicken brains are highly digestible while chicken skulls, being comprised of bone, are less so. So it appears to be a zero sum game when it comes to the added chicken heads. Last – chicken feet. As a food ingredient that is intended to provide dietary protein, feet are simply bad and have measured quality values similar to feeding connective tissue or bone residue.

Feet Less than symbol Heads  Less than symbol Chicken Guts

       FEET (BAD)                                        HEADS (LESS BAD)                           GUTS (BETTER)

Collectively speaking, including additional body parts in a by-product meal may affect the resultant product’s protein quality either positively or negatively when compared with its corresponding meal. The influence depends largely upon the actual proportion of the three different body parts that are included in the end product: if there are lots of guts, quality improves. Heads: could go either way. Feet: bad news.

And, by the way, specifics on the type and quantity of these additions is information that consumers are never privy to.

So, Why All the Hype? Studies of the digestibility and protein quality of meals and by-product meals have found that as a group, meals are slightly more digestible and contain slightly more available essential amino acids than their associated by-product meals (3,4). However, there is also a lot of overlap between the two ingredient groups, meaning that a given meal may be better, equal to or even lower in quality than a given by-product meal.

Overall, the differences that have been found are neither dramatic nor worthy of the hysteria that seems to accompany the word “by-product” among dog owners and some pet food companies. Therefore, the marketing hyperbole and excessive “patting oneself on the back” by companies that include meals but not by-product meals should be viewed by all dog owners with a hefty dose of skepticism. True, there is some difference, but probably not enough of a quality difference to warrant the inflammatory language and excessive claims that are being made by companies jumping on the by-product-free bandwagon.

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Draggin’ Out the Ol’ Box Again: I would suggest that this exaggeration of difference has occurred (and been actively promoted) because there are so few available ways for dog owners to accurately assess the quality of ingredients, especially protein ingredients, in commercial pet foods. As a result, this single AAFCO-defined difference (meals vs. by-product meals) has caught on like a house on fire, with marketing campaigns flinging additional gasoline to fuel the flames and causing this distinction-without-a-difference to garner more importance than it comes even close to warranting.

It is an unfortunate paradox that one of the most important nutrients for dogs (protein) is supplied by a type of ingredient (protein meals) that consumers have almost no way of evaluating. This is especially concerning given that animal-source meals can vary tremendously in the components that make them up and ultimately in their quality (i.e. in nutrient content and digestibility). The three designators discussed previously —plant- vs. animal-source, species vs. generic and meal vs. by-product meal — are the only protein-ingredient quality designators available to consumers. This might not be an issue if they were in truth the most important quality differences among animal protein meals. However, they are not. Animal protein meals differ in ways that are invisible to consumers and can significantly influence the quality of the foods in which they are used:

  • Bone and connective tissue: Animal-source protein meals contain varying amounts of bone and connective tissues (this pertains to both meals and by-product meals), which affects the product’s protein quality and mineral balance. Bone matrix and connective tissues contain the protein collagen, which is poorly digested and utilized when included as a dietary protein source, and bone contributes excess amounts of calcium and several other minerals. Meals that are high in collagen and minerals from bone and connective tissues are of lower quality than those that contain a larger proportion of muscle meat.
  • Transport and contamination: Because inedible food products are not refrigerated or subject to the same handling regulations as foods destined for human consumption, both the handling and transportation of raw materials can affect the quality of the end product. If rendering is conducted at the slaughterhouse of origin, the meal is usually produced within a day or two following slaughter. However, when raw materials are transported to a rendering plant in another location, the time spent during transport under unrefrigerated conditions can lead to increased microbial contamination and oxidative damage.
  • Processing: Differences among rendering plants also exist and are important for the end product. High temperatures or excessively long cooking can damage a meal’s protein, making certain essential amino acids less digestible and available.
  • Supplier integrity: Finally, as seen with the Blue Buffalo case, pet food companies are at least somewhat dependent upon the integrity and honesty of their ingredient suppliers. A division within the animal feed industry designates some meals as pet-food grade and others as feed grade, with the former containing a lower percentage of ash (minerals) (5). In addition, some pet food companies select only meals that meet a particular standard, while others impose additional refining methods on their protein meals to increase digestibility and improve protein quality.
  • Tests that we do not hear about: Various analytical tests are used to measure a meal’s digestibility and amino acid availability, and many pet food companies also routinely measure the digestibility of their foods using feeding trials. However, this information is not easily available to consumers, and pet food companies are under no obligation to accept or reject meals of different quality levels or to share such information with consumers.

To date, there is no way for pet owners to differentiate among dry (extruded) dog foods that use high-quality animal protein meals and those that use poor-quality meals, other than the cost of the food and the three designators discussed previously. You can contact the company and specifically ask for information about the food’s protein digestibility and quality, of course. However, you may be disappointed. While researching my book Dog Food Logic, I contacted the manufacturers of more than 30 different pet-food brands and requested protein and diet digestibility information for each of the products. I received no reply at all from the majority of companies and useful information for just two of the brands.

 Are There Any Other Options? In today’s innovative market place, there are indeed a few. Two other animal-source protein ingredients (in addition to fresh meats prepared at home) are those that are either freeze-dried or dehydrated. Freeze-dried ingredients are typically used in raw food diets, but can also be cooked prior to packaging. Dehydration usually uses heat treatment to kill microbial growth and so moderately cooks the meat. These sources are likely to be of higher quality and digestibility because they have not undergone the high heat processing that meals are subjected to.

Dehydrated chicken                           Freeze dried chicken                 DEHYDRATED CHICKEN                                        FREEZE-DRIED CHICKEN 

If they are human-grade meats, all the better, as this means that the ingredients and the end-products were handled and produced using the same regulatory oversight as required with human foods. However, with a few exceptions, neither freeze-dried nor dehydrated meat sources are routinely used as the primary protein source in dry, extruded foods. Nor have I found a source of dried protein meals produced using human grade (i.e., edible) meat sources and human food processing methods. To do so (and to promote them as such) would add a dimension of choice and distinction regarding the quality of dry dog food that does not exist today. Dry extruded dog food continues to be the most popular type of dog food sold in the U.S., and I believe such products would be welcomed by owners willing to pay a bit more for a better regulated and higher quality food.

Take Away for Dog Folks: While rendered animal meals can be of high quality and can provide an excellent protein source in dry dog foods, if the animal-source meal has been poorly sourced, handled, processed, or regulated, its protein can be damaged, making it a poor source of essential amino acids for dogs and reducing the digestibility and quality of the entire diet. Unfortunately, there is no way for consumers to tell from a food’s label if the meal used is of high, moderate or low quality. Because meals make up the bulk of protein in dry dog foods, information about their quality, and by extension, how nourishing they are, is the most important consideration that we should be concerned with when we look at an ingredient list.

The problem is, despite what companies beating the “No By-Products” drum would like us to believe, we have no way of knowing which animal protein meals are better than others.

Cited References

  1.  Association of American Feed Control Officials. 2010. Official Feed Definitions; pp. 326–322.
  2. Aldrich, Daristotle. 1988. Petfood and the economic impact. Proceedings of the California Animal Nutrition Conference, Fresno, CA; pp. 1140–1148.
  3. Cramer, Greenwood, Moritz. 2007. Protein quality of various raw and rendered by-products commonly incorporated into companion animal diets. Journal of Animal Science 85:3285–3293.
  4. Locatelli, Howhler. 2003. Poultry byproduct meal: Consider protein quality and variability. Feed Management 54:6–10.
  5. Dozier, Dale, Dove. 2003. Nutrient composition of feed-grade and pet-food-grade poultry by-product meal. Journal of Applied Poultry Research 12:526–530.

Excerpted from: “Only Have Eyes for Your: Exploring Canine Research with the Science Dog” (2016).

coversnip

What’s in YOUR Food? (Revisited)

In an earlier blog essay, “What’s in Your Food?” I reviewed the results of four published studies that compared the animal protein ingredients listed on various pet food labels with the actual ingredients found in the foods. Multiple instances of mislabeling occurred in which undeclared animal species were included as ingredients and/or protein ingredients declared on the label were completely absent.

canned dog food comic

This month, another study was published (1).  Although this work was conducted in the UK and examined canned pet foods only, it was unique in one important way. Unlike the four previous studies, this group of researchers revealed the brand names of every single product that they examined.

All I can say is; It’s about time.

The Study: According to the authors, the objective of their study was to “examine the correlation between the composition of different animal proteins and the animal species disclosed on pet food labels“. Now, a naïve person might assume that such a correlation would be, oh, in the vicinity of, say…..1.0. But, we now know that this is not only naïve, but an assumption that has already been shown to be patently false. The authors tested 17 different brands of canned (i.e. wet) dog or cat foods available for purchase at UK supermarkets for the presence of cow, chicken, pig and horse meat DNA.

Results: None of the foods contained horsemeat. However, there the good news ends. Of the 17 foods, animal species that were not listed on the food’s label were found in 14 (82 %) of the products. Several errors worth noting include:

  • Hill’s Prescription Diet R/D Feline Weight Loss listed chicken immediately after pork on its ingredient panel, yet contained no chicken (0 percent).
  • Seven products included the phrase “with beef” in their brand name or prominently displayed on the label. The protein in four of these foods came predominantly from pork and chicken (75 to 86 % of protein). These products included a Pedigree (Mars) brand, two Nestle’-Purina brands, and a UK private label brand.
  • A Mars brand (Chappie) that stated “14 % whitefish” on its ingredient panel actually contained no fish at all; 100 % of its protein came from chicken. An ALDI private label brand called “Salmon in Pate” listed fish first on its label, did not report chicken at all, and yet was 92 % chicken.
  • Of six pet foods that highlighted “chicken” on the label or in the brand name, two products, both private label brands, contained more pig or beef protein than chicken protein.

soapbox

Up on my Soapbox: The authors of this study note that technically most (not all) of these foods were still in compliance with EU pet food regulations. The finding of large proportions of chicken and pork in foods that reported no such species on their ingredient panels was technically correct provided the term “meat and animal derivatives” was found somewhere on the list. Unbeknownst to most consumers, this term includes “all products and derivatives of the processing……of warm-blooded land animals“.  That covers everything from chickens to well, pretty much anything that has blood and feet. The second issue is the ubiquitous word “with“. Similar to regulations in the United States, EU standards require that pet foods using this descriptor contain….wait for it…..a minimum of only 4 % of the designated ingredient. (In the US, the minimum is a whopping 3 %). And as these products demonstrate, 4 percent is about what you get.

As the authors of this study note, and I agree, there appears to be a serious mismatch between label standards in the pet food industry and what consumers are lead to believe about the foods that they purchase for their animal companions. Is it not reasonable for my friend Alice to expect that the  food she selects for her Yorkie called “Gourmet Terrine with Chicken and Game” actually contain more than 1 percent of its protein from chicken, not as is the reality, almost 90 percent of it coming from beef? And when my elderly neighbor Joe carefully selects food for his beloved cat Pumpkin, is it silly for him to expect that “Felix Complete with Beef” contains a substantial proportion of, say……beef?

Just as we need increased transparency from the pet food (and human food) industry regarding the source of ingredients, processing methods, measures of quality, and safety records, it appears that we also need regulations that prevent rather than support misleading label claims and brand names. Is it really too much to ask that a pet food actually contains what it claims to contain (and nothing else)?

Cited Study: Maine IR, Atterbury R, Chang KC. Investigation into the animal species contents of popular wet pet foods. Acta Veterinaria Scandinavica 2015; 57:7-11.