Our Best Friends’ Friends

Our  Golden, Cooper has a friend named Pete. Cooper and Pete groom each other, take naps together on a favorite bed, and play their own special version of “wolf and caribou” around the dining room table. When Coop goes on walks, he likes to have Pete come along with us.

And oh yeah, Pete is our cat.

Pete and Cooper

Many folks who live with dogs and cats are not surprised by this friendship and have great stories of their own to tell about a special bond between a dog and cat. However, the myth that dogs do not particularly like cats certainly continues to persist.


Likewise, it is generally accepted that not all cats are pleased about having to share their home with a dog.

Cat Text about Dog

The underlying foundation for the assumption that dogs and cats cannot be friends is perhaps the fact that they are vastly dissimilar species, with different evolutionary histories, social behaviors and communication patterns. Apparently, their interest in play varies as well.


Regardless, anecdotal evidence abounds about the ability of individuals from the two species to form close and enduring friendships. And, I found recently, there is even a bit of science to back up these stories.

The Study:  A group of investigators from Tel Aviv University in Israel interviewed 170 pet owners who lived with both a dog and a cat (1). The study also included direct observations of the pets in 45 of the homes.

Results: Not only do dogs and cats get along well, they also appear to be able to learn quite a bit about communicating with each other:

  • The majority of the owners (> 60 %) reported that their dog and cat were amicable and friendly toward each other and less than 1 in 10 owners reported aggressive behaviors.  (The remaining pets were largely indifferent to each other).
  • Mutual play made up a substantial proportion of the interactions between dogs and cats, as did staying in the same room or resting and sleeping  together. Interestingly, the cats in the study offered significantly more play soliciting behaviors to their dog friends than vice versa.
  • Perhaps not surprisingly, the two factors that were found to be important determinants for influencing the dog/cat relationship were the order of adoption (friendships were more likely when cats were adopted first) and age of adoption (friendships were more likely when both animals were adopted when they were young).

Take Away for Dog (and Cat) Folks: One of the most interesting results from this study had to do with the types of communication signals that were used by the dog and cat friends. More than 75 % of the greeting behaviors between these friends occurred in the form of a  “nose-touch”, which is considered to be a common feline-specific greeting pattern, rather than a canine-specific greeting signal.

Chapter 1 Figure 9     Chapter 1 Figure 10

The researchers also reported several communication signals that had an unrelated or opposite meaning to the other species, yet were still correctly interpreted by the receiving animal.  Examples of these included lying on the back (submission or play in dogs versus aggression or predation in cats) and stretching out the forefeet (play in dogs versus aggression in cats). This is pretty cool stuff as it suggests that dogs and cats who share a home and become friends not only enjoy hanging out, playing, and resting together, but also appear to learn each others body language, even when certain signals may mean something very different in their own species.

As for Pete and Cooper, they both say, “Yeah? No big surprise there!”Pete and Cooper Playing1

Cited Study: Feuersten N, Terkel J. Interrelationships of dogs (Canis familiaris) and cats (Felis catus) living under the same roof.  Applied Animal Behaviour Science 2008; 113:150-165.

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.


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.




Keep those Doggies Rollin’……Rawhide, Rawhide!

I have always hoped that someday I would find a connection between the Blues Brothers and dog nutrition. That day has come.

Rawhide, Rawhide: A dog person cannot walk into a pet supply store (or their own grocery store, for that matter) without noticing the explosion in the number of dog chews, dental devices and edible bones that are available for sale today. Some of these are biscuit or extruded concoctions containing a mixture of ingredients, while others originate from cow skin (rawhide chews) or are the left-over body parts of a hapless food animal (pig/lamb ears, hooves, and bully sticks).

If you do not know what a bully stick is, ask your mother. Better yet, ask your father.

rawhide knots    Bully Sticks   Pig ears  Hooves

Even as the selection of these items has expanded, nutritional information about them is still glaringly absent. Since all of these products are intended to be chewed slowly so that pieces or the entire product will be gradually consumed by the dog, we should at least be informed as to whether these items are actually digested by dogs, should we not?

Are they digestible? Dry matter digestibility refers to the proportion of a food that a dog’s gastrointestinal tract is capable of breaking down (digesting) and absorbing into the body. When we talk about the digestibility of a dog food, we are primarily concerned with its nutrient value and ability to nourish the dog. However, when we are considering the digestibility of rawhide treats, chews and dental products, the concerns are different but equally important. Any portion of a chew that is broken off and swallowed will travel through the length of a dog’s gastrointestinal tract, just like any other food. And, if the dog is able to bite off large chunks or swallow an entire chew at once, that piece has the potential to cause digestive upset, impede normal gut motility, or in the worse case scenario, cause obstruction if it is not dissolved and digested as it moves along.

Recently, a team of researchers at the University of Illinois decided to examine exactly this question by comparing the digestibility of different types of dog chews.

The studies: Two studies were conducted, both using an in vitro (test tube) technique that has been validated as a measure of the digestive conditions that occur in a dog’s stomach (gastric digestion) and small intestine (intestinal digestion). The first study compared in vitro dry matter digestibilities of sample products from six broad categories of dog treats (1). All of the products that were tested were produced by Hartz Mountain Corporation and the study was funded by the company. The second study compared just two types of treats, pork skin versus beef rawhide chews (2). The researchers also measured digestibility of the pork skin chew using a feeding trial with dogs. (For an explanation of digestibility trials with dogs, see Scoopin’ for Science). The reason for not doing a feeding study with the beef rawhide chew was not explained in the paper.

Results: Together, the two studies reported several interesting differences between the digestibility of dog chews:

  1. Chews made from pig’s ears, which are composed primarily of cartilage and the protein collagen had very low gastric (stomach) digestibilities (14 %). Although these were almost completely digested in the intestinal environment (90 %), the lack of change in gastric acid means that a pig’s ear treat, if swallowed, would potentially leave the stomach intact and enter the small intestine will little change in size and consistency.
  2. Similarly, with the exception of one product, rawhide chews made from cow skin were very poorly digested in the stomach. Intestinal digestion was almost complete for one product, but others continued to have low digestibility, even in the intestinal environment. The researchers noted that feeding rawhide chews to a dog who tended to consume large pieces could increase a dog’s risk for intestinal blockage.
  3. When a pork skin chew was compared directly to a beef rawhide chew, the pork skin product’s digestibility was significantly greater than that of beef rawhide chew. After six hours, which is approximately the time it takes for a meal to begin to leave a dog’s stomach and enter the small intestine, the pork chew was more than 50 percent digested, while the rawhide was only 7.6 percent digested. This low rate of gastric break down continued even when tested up to 24 hours. After simulation of digestion in the small intestine (the major site of digestive processes in dogs), the pork skin rawhide was almost 100 % digested, while the beef rawhide reached only 50 to 70 % digestion under the same conditions. Rawhide was digested up to 85 % only when exposed to the intestinal conditions for 24 hours.
  4. When dogs were fed one pork skin chew per day along with their normal diet, the overall digestibility of the diet increased. This corroborates the in vitro results and supports the conclusion that the pork skin chews were highly digestible.

Take Away for Dog Folks:

One of the most interesting results of these studies was the finding of such a large difference between the digestibility of pork skin versus beef rawhide chews. Because some dogs consume these types of chews rapidly and swallow large chunks, the fact that pork chews but not beef rawhides are highly degraded in the stomach and are highly digestible overall, is of significance to dog owners. These data suggest that if an owner is going to feed some type of rawhide chew (and mind you, I am not advocating for feeding these types of treats), but if one was choosing and had a dog who might consume the treat rapidly, feeding a pork skin chew appears to be a safer bet than a beef rawhide chew.

Second, it is important to note that all types of rawhide-type chews are composed of collagen, a  structural protein that makes up most of the connective tissues in the body. This is true for ears, pig skin, rawhide, and yes, even bully sticks. As these data show, collagen can be highly digestible (or not). The difference most likely depends on the source of the product and the type of processing that is used, both of which vary a great deal among products.

Feeding  dog a chew that is composed of collagen, even when it is highly digestible collagen, does not a nutritious treat make. Although collagen is a very important and essential protein in the body, it is not a highly nutritious food protein because it is composed almost completely of non-essential amino acids and is deficient in four of the essential amino acids. What this means from a practical perspective is that even though certain types of rawhide chews are found to be highly digestible and safe (from a digestibility perspective), this does not mean that they are providing high quality nutrition to the dog. In fact, they do not. While this research is important for pushing the peanut forward regarding the safety of these products in terms of digestibility, effects on gut motility, and risk of blockage, we still need more information (and selection) of chews for dogs that are both digestible and nutritious.

Cited Studies:

  1. de Godoy MRC, Vermillion R, Bauer LL, Yamka R, Frantz N, Jia T, Fahey GC Jr, Swanson KS. In vitro disappearance characteristics of selected categories of commercially available dog treats. Journal of Nutritional Science 2014; 3:e47;1-4.
  2. Hooda S, Ferreira LG, Latour MA, Bauer LL, Gahey GC Jr, Swanson KS. In vitro digestibility of expanded pork skin and rawhide chews, and digestion and metabolic characteristics of expanded pork skin chews in healthy adult dogs. Journal of Animal Science 2012; 90:4355-4361.

(Note: These studies and this blog essay do not address the ongoing and well-publicized problems with chicken jerky treats and illness in dogs. That is a topic for another time, another post).


Air, It’s What’s for Dinner

Every once in a while, I read a paper that makes me scratch my head. Last week was just such a moment. The paper really needs no introduction. The title says it all: “Increasing volume of food by incorporating air reduces energy intake” [in dogs].


Let’s talk about obesity (again): If you read “Do you think I look fat in this collar?” you will remember that obesity is the most prevalent nutritional disorder in pet dogs today. Moreover, there is evidence that a substantial number of owners do not recognize overweight conditions in their dogs and even when they do, are unwilling or unable to comply with weight loss recommendations.

Stealing food


In their search to identify new approaches to weight control (preferably approaches that can be marketed into a new brand of dog food), some pet food companies have looked at the effects of diluting food calories. An example is increasing dietary fiber. This reduces the number of calories provided in a cup of food. Consuming foods that are high in non-fermentable fibers may also enhance feelings of satiety (fullness) in dogs, although the evidence for this effect is not conclusive. However, feeding high levels of dietary fiber causes increased defecation frequency and stool quantity, often producing voluminous poops that are loose and smelly, effects that most owners are not looking for in a dog food.

Recently, in their quest to find a canine version of the weight loss Holy Grail, researchers latched on to a nutrient that most of us would probably not even consider when thinking about keeping Muffin trim. (We would not consider it because it is actually not a nutrient).

Air Bites


The Study: A group of researchers at the Royal Canin Research Center, at the National College of Veterinary Medicine in France and at the University of Liverpool in the UK collaborated to study the effects of feeding a dry dog food formulated to contain more air (1). They wanted to determine if there was a satiety-producing effect of adding air to extruded kibbles, thereby increasing the volume that is fed whilst delivering the same number of calories. This is essentially a cheaper version of the “let’s add fiber to dog food to dilute its calories” approach.

To understand this concept, consider the density (weight/volume) of a cup of corn meal compared with the density of a cup of air-popped popcorn. Same food; more air in the latter than the former. As a result, the cup of popped corn will contain fewer calories and nutrients than the cup of ground corn meal. When we are talking about extruded dog food, this idea is quite easy to put into practice because varying  extrusion conditions during processing can lead to different degrees of expansion in the end product. Highly expanded kibbles contain more air pockets, will feel lighter (because they are), and will provide fewer calories per cup than a food that has the same nutrient formulation but is less expanded. Compare the two examples below:

High Density Dry Food                Low Density Dry Food

The food on the left is a very dense product and provides about 460 kcal/cup when fed to a dog. The food on the right is less dense (you can see the little air pockets in the kibbles), and provides about 320 kcal/cup when fed. (Note: Multiple factors, not only air, affect a food’s energy density. These include the food’s digestibility and fat content, among other attributes).

The Air-enhanced Food: The researchers created a test diet that was extruded to include a higher proportion of air than that which is typical. Simply expanding the kibbles to a greater degree and increasing its trapped air pockets resulted in a caloric density that was about half that of the control food. The control diet was a food that contained the same ingredients and nutrient profile, but less air. The researchers conducted three feeding trials:

  • Experiment 1 measured the length of time that it took dogs to consume a meal that contained  increasing proportions of the test diet while still providing the same number of calories. Therefore,  because the test food contained less than half of the calories per cup than the control food, the amount of food that was fed more than doubled when the test diet was fed exclusively. Results: Not surprisingly, it took dogs longer to eat the larger meals of air-enhanced food than it took them to eat the smaller volume of food that they were given of the control diet. (In other words, it took the dogs longer to eat, um……more food). Although this sounds obvious, there is some evidence (in human subjects) that slowing down the rate of eating while consuming the same number of calories enhances satiety by increasing the release and effects of satiety-inducing and appetite-suppressing hormones.
  • Experiment 2 fed the test food and the control food to a group of 10 adult Beagles and used a standard procedure used to measure satiety. This methodology involves offering dogs more food than they are expected to eat in sequential meals spaced one hour apart (kinda like “first breakfast and second breakfast” for Hobbit fans).  Results: Adding air to food slightly enhanced feelings of satiety in dogs. This means that the dogs consumed a bit less food each day (and fewer calories) of the air-enhanced food when allowed to eat all that they desired than they did of the control food. This effect is similar to the expectation that consuming a high fiber food will lead to making one feel a bit more full and subsequently to consuming less food overall.
  • Experiment 3 used the same protocol as Experiment 2 and compared the satiety-inducing effects of the test diet with a commercially available adult maintenance dog food. The commercial food provided more than 3 times the calories per cup as the test, air-enhanced food. Results: The results were similar to those of Experiment 2. Adding air (lots of it, by comparison) to a food moderately enhanced feelings of satiety in the dogs. I envision a group of over-stuffed Beagles, burping politely (and repeatedly….it is air after all), and saying “Really. No. I couldn’t eat another bite”.


The researchers concluded: “….results from the present study indicate that incorporating air into food provides a strategy to reduce energy [caloric] intake in dogs and, consequently could be a useful strategy for weight management in pets.”  They also note that this study did not show whether or not dogs would reduce their intake of air-enhanced food to levels that would  lead to weight loss nor did it measure effects for more than a few days. They assure us that such research is yet to come.


Draggin’ Out the Ol’ Box: Even if it can be shown that increasing the amount of air in a dog’s food enhances satiety, do we really need such a food? If one’s goals are to reduce a dog’s caloric intake and slow rate of eating, there are already effective approaches that owners can take. We can first select a high quality food (or home prepared diet) that is well-matched to our dog’s lifestyle and activity level. If a dog gains too much weight, we can reduce the amount that is fed or switch to a food that is still of high quality but is lower in fat (i.e. less energy dense without diluting calories). Increasing exercise through daily walks, engaging in a new dog training activity or sport, or teaching retrieve or “find it” games will all burn more calories and help increase a dog’s fitness level.

What about satiety? Is it true that feeding a larger volume of food or slowing the rate of eating will help our dogs to feel more satisfied? Perhaps. There is certainly some evidence to support this theory.  However, while the hormonal changes associated with a slower rate of eating may enhance feelings of satiety, do we really need to inject air into our dog’s food to accomplish this? Many owners spread out their dog’s daily meal time by using a food delivery toy that their dog enjoys or feed using a “slow” bowl that is constructed to make the dog work a bit harder for his food. Feeding multiple small meals a day or floating dry food in warm water prior to feeding can be helpful to slow rate of eating as well.

Surely, we should not be expected to view injecting air into food as the new miracle weight loss approach for dogs. Are we really destined to see a new brand of dog food on the shelves selling under the marketing slogan of “Let Them Eat Air“? 

Skeptical Dog

Cited Study: Serisier S,Pizzagalli A, Leclerc L, Feugier A, Nguyen P, Biourge V, German AJ. Increasing volume of food by incorporating air reduces energy intake. Journal of Nutritional Science 2104; 3;e59:1-5.


Scoopin’ for Science

I was at the gym recently, swimming laps. After my work-out, I was sitting by the side of the pool and a fellow swimmer and friend stopped to chat about dogs. He has never owned a dog, but his daughter has been pressuring him and he thinks she is finally old enough to take on the responsibility of caring for a dog (good dad!). So, I was anticipating a discussion about breeds, where to look, training, feeding, etc. That is not where this was going at all. Instead, he wanted to talk about poop:

Me: “So, does she have a breed or breed-type that she is considering?”

Him: “No…..not yet. What I really want to ask you about is……the poop thing.”

Me: “Um…..what?”

Him: “You know. I see all of the people in our neighborhood taking their dogs for a  walk in the morning and they all carry these bags with them and then, ugh…..they all PICK UP THE POOP WITH THEIR HANDS!!!!”

Me: “Well, not exactly; there is a plastic baggie involved. But regardless, what is your point?”

Him: “I just find that so gross and disgusting. I don’t think I could do it.”

Me: “Wh…What???”

Him: “Ick. Yuck.” (Accompanied by a squeamish expression that I have never seen on the face of a grown man).

Me; “Okay, let me get this straight. You are a triathlete. You regularly beat the crap out of your body by swimming, running and cycling ridiculously long distances. You have backpacked and camped all over the country, with no “facilities’ and sometimes not bathing for days……and you squirm at picking up dog poop in a plastic baggie?”

Him: “Yeah, that about covers it.”

Me (laughing): “You gotta get over that dude. Take a class or something. All dog folks pick up poop. It’s no big deal.”

Him: “Hmmm…..” (not buying it).

Baggie poop

It really is no big deal. Many dog owners are not only comfortable with poop scooping, we also regularly examine the quality of our dog’s leavings as a general barometer of their health and the quality of the food that we are feeding.

So, when I learned of a recent study that asked a group of dog owners to do some “poop scoopin’ for science” I was only surprised that there have not been more studies of this nature published in the past.

The Issue: Those of you who have read Dog Food Logic know that I personally advocate for increased transparency in the pet food industry and for the need to provide dog owners with information that is actually useful to us when selecting foods. Without question, one of the most important measures of  a food’s quality is its digestibility – the proportion of the food that a dog’s gastrointestinal tract is able to actually break down (digest) and absorb into the body for use.  Digestibility correlates well with both ingredient quality and proper food processing techniques, so this information would be very helpful for dog owners to have. However, the vast majority of companies do not provide it. The only (very rough) estimate of food digestibility that we have is that gleaned by regularly examining the quality and quantity of our dog’s feces. A behavior that, in addition to providing very little real information, lends itself to weird looks from neighbors such as my swimming friend. A crappy state of affairs, indeed.

Industry’s Position: When challenged, representatives of the pet food industry generally deflect criticism by maintaining that current AAFCO regulations do not require reporting of food digestibility. (The old “we don’t gotta so we ain’t gonna” defense). Further, not all pet food companies regularly measure digestibility because doing so requires them to conduct feeding trials with dogs which in turn requires access to research kennels and laboratories. Such studies are expensive and may be cost prohibitive for some of the smaller companies that do not maintain their own kennels or in-house analytical laboratories.

Fair enough. However, what about using dogs who live in homes? Why not enlist everyday Citizen Scientists who are dedicated to their dogs, feed commercial dog food, are concerned about quality, and who do not squirm at picking up dog poop? Not only would this lead to increased numbers of dogs enrolled in these trials (thus supporting improved accuracy of digestibility estimates), it would also allow needed comparisons among breeds, ages, life styles and activity levels of dogs, and could get information about food quality out to the consumers who need it. Another definite advantage of in-home studies is that they lead to reduced need for kenneled research dogs, a clear animal welfare benefit.

Happily for us, a group of researchers from two universities in The Netherlands were thinking the same thing (1).

The Study: The objective of their study was to develop a simple method of measuring dog food digestibility that could be used with privately owned dogs living in homes. They recruited a group of 40 adult, healthy dogs and asked their owners to feed a test food (and nothing else) for a period of 7 days. Amounts to feed each dog were pre-measured and the volume the dog consumed each day was recorded. In this study, the test diet was a commercial dry (extruded) food formulated for adult dogs. After seven days of feeding, the owners were asked to collect all of their dog’s feces for a period of 24-hours. The feces were frozen and submitted to the researchers for analysis.

Here is a flow-chart showing how a digestibility trial works. It is conducted in the same manner with kenneled dogs, although feeding and feces collection periods can vary:

Digest Trials

Results: The owners recorded the amount of food that their dog consumed each day and collected all of their dog’s feces over the final 24-hours of the study. The researchers then analyzed the nutrient content in the food that was consumed and in the feces that were excreted. From these data, they calculated the proportion of the food that each dog digested, called a “digestibility coefficient” and average values for the entire sample of dogs. In this experiment, the food’s dry matter digestibility was 77.4 % and its protein digestibility was 77.7 %, values that reflect a food of “low to moderate” quality. The variability between dogs (as reflected by the standard errors), was found to be low. This suggests that the dogs in the trial showed consistency in their ability to digest the food and supports the in-home trial as a valid procedure. In addition, the study reported compliance in 39 out of 40 homes, demonstrating some pretty dedicated poop scooping.


Up on the ol’ Box: Another recent study evaluated a set of eight commercial dog foods using both nutrient analysis and a set of feeding trials like the one above, but with kenneled dogs (2). They found a very wide range in the overall (dry matter) digestibilities and protein digestibilities among the eight products and noted that these differences would not be reflected by information that was provided on the pet food labels. The authors went even further, stating: “…we have to note that there is no comprehensive list of information available to the consumer to evaluate the quality of commercial diets. A combination of laboratory analyses and estimation of digestibility coefficients is the only way to perform an accurate and complete evaluation of the quality of a commercial diet”  And yet, not all pet food companies supply complete nutrient levels for their foods and no pet food companies regularly provides digestibility coefficients to dog owners.

The results of this pilot study tell us that in-home studies with owned dogs can provide needed information about dog food quality and can allow the study of factors that may influence how well dogs utilize different foods, such as age, breed, size, health status and activity levels. Compliance was very good; these owners were willing to do their part, scooping poop for science. Now all that we need is for pet food companies to step up and begin to conduct in-home studies and make the information that they provide available to the dog folks who care.

Cited Studies:

  1. Hagen-Plantinga EA, Bosch G, Hendriks WH. Practical approach to determine apparent digestibility of canine diets. Journal of Nutritional Science 2014;3;e31:1-4.
  2.  Daumas C, Paragon BM, Thorin C, Martin L, Dumon H, Ninet S, Nguyen P. Evaluation of eight commercial dog diets. Journal of Nutritional Science 2014;3;e63:1-5.





“Dog Food Logic” Wins Maxwell Award!

My publisher, Dogwise, informed me last week that my book “Dog Food Logic: Making Smart Decisions for your Dog in an Age of Too Many Choices” has won the Dog Writer’s Association of America’s Maxwell Award for Best Health Care Book of 2014! For more information about “Dog Food Logic” and about my newest book “Beware the Straw Man” click the links below.

dog-food-logic-cover-final               Beware Straw Man Cover

“Do you think I look fat in this collar?”

Said no dog. Ever.

This is how dogs more likely consider the possibility of being overweight:

Fat Sounds Awesome

Most owners are aware that it is our responsibility to keep our dogs at a healthy body weight and in good condition. We all know this, right?

Perhaps not. A few statistics:

  • Obesity continues to be the number one nutritional problem in pet dogs in the United States.
  • According to the Association of Pet Obesity Prevention (APOP), veterinarians classified 53 percent of their canine patients as either overweight or obese.
  • In the same survey, only 22 percent of the owners identified their dog as being overweight.
  • APOP founder Dr. Ernie Ward refers to this cognitive disconnect as the “fat pet gap”. He suggests that American dog owners’ perceptions of what is normal in their dogs has been gradually distorted, leading to the perception that an overweight body type is normal.
Two Fat Labs


Why the Disconnect? A common theory used to explain the mismatch between what owners perceive and what their dog actually looks like is that owners simply have not been taught how to recognize a fat dog and lack the knowledge to differentiate between a dog who is at ideal weight versus one who is slightly (or more) overweight. In an attempt to counteract this problem, pet food companies created Body Condition Scores. These are standardized five to 9-point visual scales designed to help owners and veterinarians correctly assess a dog’s body condition. Here are two examples:

5 point BCS         Purina BCS

Problem solved? These scales have been around for more than 15 years. Yet, our dogs are still fat. Perhaps the scales are not being used? Are they difficult to understand? Recently a group of researchers asked the question: “If we give dog owners a BCS tool, show them how to use it, and then ask them to evaluate their own dog using the tool, will their assessments improve?”  Their hypothesis was optimistic. They believed this would do the trick.

The Study: This was a pre-test/post-test study design and included a group of 110 owners and their dogs (1). In the pre-test portion of the study, the owner was asked to assess their dog’s body condition. No guidance was provided and the owner was required to select the word that best described their dog from a set of five terms; very thin, thin, ideal weight, overweight, or markedly obese. Following this assessment, the owner was provided with a five-point BCS chart that used the same five descriptors along with visual silhouettes and descriptions. They were given instructions of how to use the chart and were then asked to assess their dog a second time. The investigating veterinarian also assessed the dog using the BCS chart and physical examination.

Results: Several interesting (and surprising) results were reported:

  1. Prior to using the BCS chart, 2/3 of the owners (66 %) incorrectly assessed their dog’s body condition. The majority underestimated body condition, believing their overweight dog to be at or near his or her ideal weight. These results are consistent with those reported by other researchers and with the APOP survey.
  2. Following training with the BCS tool, these misperceptions persisted, showing virtually no change; 65 % were incorrect and only 15 % of owners changed their original score (some up/some down, and some from correct to incorrect!). The majority of owners continued to see their plump dog as being at his or her optimal weight.
  3. Here is where things get really weird.
    • When queried, the majority of owners (77 %) stated that they believed that using the BCS chart had significantly improved their ability to estimate their dog’s body condition (huh?). This statement was made despite the fact that only 17 owners changed their scores after they learned to use the chart.
    • And, those who believed the chart had helped them fared no better in post-test success than the those who believed that the chart did not help them.

Get Fuzzy Fat Sachel

Take Away for Dog Folks: This study confirms what several other researchers have reported and what the APOP statistics tell us; dog owners tend to underestimate their dog’s weight and body condition, seeing a dog who is overweight as ideal. It also goes an important step further. Even when owners are shown how to identify an overweight dog, they are literally blind to seeing the evidence in their own dog. We still get it wrong. Why is this happening? There are a few possible reasons:

  • Fido is not fat; he just has big bones: Resistance to seeing one’s own dog as overweight may be a form of denial, similar to the well-documented misperception  that many parents have regarding their child’s weight. Because being overweight is viewed negatively by others, is associated with well-known health risks, and may be perceived as reflecting badly upon a dog owner’s ability to care properly for their dog, denial may be quite an attractive alternative to the truth. 
  • Confirmation bias: In this pre-test/post-test situation, people may have resisted changing their scores following training simply because, well, people hate to be proven wrong. If an owner had preconceived beliefs about his dog’s weight and initially assigned a moderate score, he might subsequently (and unconsciously) use the BCS chart to confirm that belief, however misguided it was.
  • Food is love: There are data from other studies showing that a substantial number of owners admit that they are unwilling to deny food to their dog even when they know the dog is overweight because they see feeding as an important outlet for love and nurturing (2). Similarly, owners tend to resist changing their feeding habits with their dogs even when aware of the adverse health effects of being overweight (3).


Soap Box Time: The results of this study are not encouraging and suggest that we have a long way to go regarding our ability to prevent and reduce overweight conditions in dogs. If you are a trainer, doggy day care owner, groomer, veterinarian, veterinary technician, or other pet professional who works daily with dog owners and their dogs, perhaps it is time for a little “tough love”. Post a BCS chart in your facility, have a weight scale handy, and don’t be afraid to use them. Call the fat dogs fat…….nicely of course and with great respect for their owners (the dogs won’t care; they will be proud). Help owners to face reality.  Provide guidelines to help dogs to trim down, encourage exercise for both the dog’s body and mind, and help people to understand that keeping a dog trim is one of the best ways that we can support their health and demonstrate our love.

Cited Studies:

  1. Eastland-Jones RC, German AJ, Holden SL, Biourge V, Pickavance LC. Owner misperception of canine body condition persists despite use of a body condition score chart. Journal of Nutritional Science 2014; 3:e45;1-5.
  2. Kienzle E, Bergler R, Mandernach A. A comparison of the feeding behavior and the human-animal relationship in owners of normal and obese dogs. Journal of Nutrition 1998; 128:2779S-2782S.
  3. Bland IM, Guthrie-Jones A, Taylor RD. Dog obesity: Owner attitudes and behavior. Preventive Veterinary Medicine 2009; 92:333-340.