“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.

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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.

 

Want Flies with that Shake?

Fries with Shake Mod

Well, not actually you, but rather your dog.

Before food purists get up in arms over  this topic, consider that numerous human cultures have historically viewed insects as acceptable and even highly desirable food items. And today, our ever-expanding human population and the increasing need for sustainable sources of food have led to increased consideration of insects as food in almost all human cultures.

Insects for Dinner

So, it’s not much of a jump to ask – what might this mean for feeding dogs?

It’s all about the protein: Protein is the most expensive nutrient in the diet of all animals, including humans. It is expensive both in terms of the monetary cost of its production and its ecological impact upon the environment. In the spirit of sustainability (a buzzword that pet food companies and other corporations love to trot out) and with the goal of reduced production costs (i.e. making foods more cheaply), pet nutritionists at The Nutro Company recently identified a number of potential alternative protein ingredients for dog and cat foods. Bugs, being plentiful, cheap, and protein-replete are included on that list.

And protein is all about amino acids: Although we talk about a dog’s protein requirement and about a food’s protein level or quality, the actual requirement that dogs and all animals have is for the essential amino acids (the building blocks of the dietary protein) and the nitrogen that dietary protein supplies. The reason that the parlance of nutrition centers on dietary protein is simply because foods contain protein, not individual amino acids. It is during the process of digestion that a food’s protein is broken down in the small intestine into its component amino acids, which are then absorbed into the body. So, at the level of an animal’s metabolic needs, it is the amino acids that actually count. This is why one of the first steps that nutritionists take when examining a potential protein-containing ingredient is to examine its amino acid composition.

So, can insect protein supply all of the essential amino acids that dogs require? The nutritionists at Nutro and at the University of California at Davis decided to find out (1).

The Study: A wide variety of different plant, algae and insect species were identified as potential alternative (and sustainable) protein sources for pet foods. Within the group of insects, the researchers focused on the adult and larval forms of various species of flies, cockroaches, and ants.

Cockroach      Ants                    COCKROACHES                                                           ANTS        

 

           Blowfly adult         Blowfly larvae                          FLY (ADULT)                                                     FLY LARVAE

All of the bug samples were analyzed for total protein and amino acid content. (I will spare you the details regarding sample acquisition and preparation in case you are reading this during your lunch hour). Amino acid analysis included measurement of the 10 essential amino acids plus taurine, a special type of amino acid that is found primarily in animal tissues. Many readers are probably familiar with taurine as an essential dietary nutrient for cats. Because there is evidence that taurine may be needed during periods of physiological stress in some dogs, it has recently been classified as a “conditional essential amino acid” for dogs as well. Because sources of taurine are limited, it is an important essential nutrient to measure when considering new ingredients for dog and cat foods.

Results: Larval and adult forms of five different insect species were analysed. Here are their primary findings:

  • High in protein: Total protein levels in all of the insect species were quite high. When reported on a dry matter basis, concentrations ranged between from 46 % in Black Soldier Fly larvae to 96 % in cockroaches. (Cockroaches? Who knew?).
  • Bugs can do it: All but one species of insect (Black Soldier Fly larvae) were found to contain sufficient concentrations of protein, essential amino acids, and taurine to meet or exceed the NRC requirements for growth for dogs and cats. The finding for taurine was rather surprising because it has been previously assumed that rich sources of taurine included only skeletal muscle and organ meats.
  • Ants and flies are best: Two groups of insects, ants and adult flesh flies, contained the most concentrated sources of taurine. However, these initial results suggest that all three of the groups that were studied – ants, cockroaches, and flies – may be nutritionally acceptable protein sources for dog and cat diets.

Take Away for Dog Folks

Dogs and cats (like humans) require nutrients in their diet, not ingredients. Therefore, if a particular protein ingredient can supply most or all of the dog’s essential amino acids, is nutritious when fed, and is safe and palatable, then it technically meets the criteria (ick factor aside) to be considered as a potential dietary ingredient. Having passed the first test of adequate protein and amino acid content, where do insects fall on these other criteria?

  • Nutritious when fed: This refers to how digestible and bioavailable the essential nutrients of the ingredient actually are, when fed to the dog. For example, some insects and plants contain anti-nutritional factors, compounds that interfere with the ability to digest or use certain nutrients. Some of these compounds can be toxic or so potent as to cause illness, making their presence a clear “no-fly zone” for pets (pun intended).
  • Safety: Many species of bugs have ways to protect themselves from becoming someone’s meal. They produce toxins that cause illness or consume plants whose by-products are toxic to animals. They may also just taste really, really nasty. Clearly, toxic bugs are out.
  • Acceptability: Living with four dogs, one of whom is a notorious poop-eater, I would venture that the acceptability issue is as much about the human side of the equation than it is the dog side. Still, dogs must not just accept a bug-flavored food, they must relish it.
Dogs Watching Eating 2

THE BOYS WATCH MIKEY AS HE TRIES THE LARVAE-FLAVORED CHOW

Will owners accept it? Might Cockroach Recipe for Seniors or Fly Formula for Active Dogs be a hard sell? My (gut) instinct is to say yes, especially in the US. We all project our own preferences and desires onto our dogs – it is our nature to do so. This is why dog foods that depict entire roasted chickens and sirloin steaks on their front panels sell so well (however misleading such graphics may actually be).

Still, seeing that there is a booming market for dog foods containing alligator meat, brushtail (Australian Possum), and Unagi (freshwater eel), along with treats made from dried bull penises, pig hooves and cow tracheas, one must admit that the bar is already set pretty low. Will insect dog food be next up?

Cited Study: McCuster S, Buff PR, Yu Z, Fascetti AJ. Amino acid content of selected plant, algae and insect species: A search for alternative protein sources for use in pet foods. Journal of Nutritional Science 2014;3:e39;1-5.

 

 

 

 

 

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.

 

 

 

Dogs are Carnivores, Right?

There is a great deal of confusion (and opinion) today regarding how to classify the domestic dog. Those who identify dogs as carnivores (meat-eating) animals tend to focus on the predatory nature of the dog’s closest cousin, the wolf. Conversely, those who are inclined to classify the dog as an omnivore (consumes both plants and meat) rely upon the dog’s scavenging nature and ability to consume and digest a wide variety of food types. So, which is it? And, perhaps more importantly why does what we call the dog, carnivore or omnivore, seem to matter so much to us? (And why do discussions about this issue seem to quickly escalate into shrillness, name-calling and spamming?)

That Escalated Quickly

First, let’s all just calm down. From a scientific viewpoint, it appears that some confusion may arise from the dual use of the term “carnivore”. This term is used as both a taxonomic classification and as a description of a species’ feeding behavior and nutrient needs. Both dogs and cats are classified within the taxonomic order of “Carnivora”, a diverse group of mammals that includes over 280 different species.

Taxonomy

Some eat meat…..some don’t: While many of the species within Carnivora hunt and consume meat, not all are predatory or nutritionally carnivorous. The species within the order Carnivora vary considerably in the degree of dependency that they have upon a meat-based diet. For example, all of the cat species, including our domestic cat, Felis catus, are obligate carnivores. In contrast, bears and raccoons consume both plant and animal foods, while the Giant Panda subsists on a vegetarian diet. Therefore, while all of the species within the order called Carnivora can eat meat, their typical feeding behaviors exist along a broader spectrum, ranging from the obligate carnivores at one end to animals that are almost completely herbivorous at the other end.

So, where does the dog fall along this spectrum?

Cats vs Dogs: Let’s consider this question by comparing our two best animal friends, the dog and the cat. The label “obligate carnivore” (sometimes called true carnivore) means that the cat is incapable of surviving on a vegetarian diet and must have at least some meat (animal tissue) in its diet. This means that a diet that is composed of all plant materials cannot meet all of the cat’s essential nutrient needs. Specific nutrients that are problematic if Fluffy is fed a vegetarian diet include Vitamin A, a type of amino acid called taurine, and an essential fatty acid called arachidonic acid. All three of these nutrients are found in a form that cats can use in meat products and but are not found in plant foods. During evolution, cats either lost or never developed the ability to produce these nutrients in the body from the precursor forms that are found in plant foods.

The Adaptable Canine: In contrast, most of the canid species, including the domestic dog, are more generalist in their eating habits and subsequently in their nutrient needs. In the wild, wolves and coyotes exist as opportunistic predators, hunting and eating the type of prey that happens to be available. In addition to the flesh of their prey, wild canids readily consume viscera (stomach, intestines) which contain partially digested plant matter. Canid species also scavenge carrion and garbage and regularly consume fruits, berries, mushrooms, and a variety of other plant materials. Similar to its wild cousins, the domestic dog is a predatory species that also consumes plant foods and scavenges, and is capable of consuming and obtaining nutrition from a wide variety of food types.

Not only does the dog naturally choose a wider variety of foods to eat than do cats; the dog is capable of deriving needed nutrients from plant foods more efficiently than do cats. Let’s look at the three nutrients that we mentioned earlier; Vitamin A, taurine and arachidonic acid:Dogs vs cats

Finally, anatomically, dogs’ gastrointestinal tracts, from their mouths to their intestines, are consistent with other predatory species (i.e. meat-eating) that consume a varied diet. They have some ability to grind food (molars), and possess a small intestine that is longer in length (relative to body size) than that of obligate carnivores, but that is shorter in length than that of herbivorous species.

Altogether, the nutrient, metabolic, and anatomical characteristics of dogs place them on the omnivorous side of the spectrum within the wide range of species who hunt prey, scavenge, and consume plant foods

Carnivore Evidence

When we look at the evidence, we see that both nutritionally and taxonomically, the dog is best classified as an omnivore, an animal that consumes and derives nutrition from both animal and plant food sources. More specifically, the dog evolved from a species that made its living primarily through hunting and consuming prey but that also consumed whatever was available through scavenging. (Anyone who lives with a Golden Retriever is well acquainted with the scavenging part).

Time to drag out the box.

soapbox

UP ON MY BOX

So, why is it that we read multiple websites, listen to certain “experts”  and talk to Joe next door (who happens to know a lot about dogs) and they insist that the dog is an (obligate) carnivore? Why are some folks so incredibly (and one might venture, obsessively) invested in this belief? Not to put too fine a point on it, many proponents of the “dog as carnivore” hold on to this conviction like a dog with a meaty bone. One may wonder, why is this distinction even important, except perhaps for academic interest?

My own opinion is that the keen interest that we see in recent years is caused by an unusual and somewhat unprecedented focus on a desire to “feed dogs naturally.” Oddly enough, prior to the development of commercially prepared dog foods in the early 1900’s, domestic dogs were fed naturally – they were fed scraps of human food…..in other words, they scavenged. So, we appear to have come full circle, with the only difference being that the fervent adherence to a mantra of “feeding dogs naturally” now focuses on the dog’s hunting and meat-eating history rather than on its equally significant existence as a proficient scavenger.

dog at table

I’D LIKE SOME OF WHAT YOU ARE HAVING, PLEASE.

Do dogs thrive on diets that include animal-based ingredients (i.e. meat, poultry, fish) – Yes, definitely (and especially if those ingredients are of high quality). Do dogs enjoy (and probably prefer) meat in their diets. Probably. Do dogs have a nutritional requirement for animal-based ingredients in their diets? No, they do not.

EXCERPTED FROM: Dog Food Logic: Making Smart Decisions for Your Dog in an Age of Too Many Choices, by Linda P. Case (click below for purchasing in formation).

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