Tuesday, December 10, 2019

Should I Switch Diets? Grain-Free, DCM, and the FDA.



   For many pet owners, it isn't news anymore-- in June 2019, the FDA released on update on their investigation into canine dilated cardiomyopathy and grain-free diets, including the names of implicated brands. This press release quickly made national news and has been covered on virtually every major pet blog and news site. The issue still leave more questions than answers though, and concerned dog owners are asking themselves, their friends, and their vets... "Do I really need to switch diets?"

     The answer ultimately boils down to a cost-benefit risk analysis. Unfortunately, we do not have controlled, scientific studies validating everything. Science is a process, and our knowledge is ever evolving. Especially in a medical context, we often have to make these risk assessments with limited and incomplete evidence. There are some people out there, owners and pet professionals alike, that are refusing to recognize the risk of an otherwise unexplained development of dilated cardiomyopathy in dogs eating certain diets. While it's true that an exact etiology has not been identified for the arising cases of DCM, it is also true that there is substantial evidence to indicate a risk associated with certain diet types, as of the FDA's June update:


  • Of the dogs reported to the FDA so far (there are likely many more affected), 91% were eating grain-free diets (far greater than the proportion of dogs in the US eating grain-free diets, holding less than 50% of the market share), and 93% were eating diets that contain peas, other legumes, or lentils. Such a strong correlation rarely arises through chance, and as of yet these correlations remain the single greatest common denominator among all affected patients. 
  • Of the cases reported to the FDA, ~11% used kangaroo as a protein source, despite kangaroo representing less than 1% of the total market share.
  • While a confounding variable like age, breed, or regional differences could be at play, the cases reported to the FDA do not suggest that to be the case. Dogs of all ages, from less than a year to 16 years, have been reported. The range of weight is from 4 lbs to over 200 lbs. Over 50 breeds are represented in the complaints submitted as of June, when including "mixed" as a single breed. It's also worth note that "mixed" breeds are the second most common breed reported, despite being the least likely to share a common genetic predisposition.   
  • Cardiologists and owners are reporting improvement with diet change, perhaps the most compelling line of evidence that diet is at the root of this issue. While many of the dogs being treated receive taurine supplements, their initial blood work (taken prior to supplementation) often returns normal, or even high, taurine levels. Taurine is also not known to reverse DCM in dogs with a genetic breed predisposition. Many of the dogs treated also receive heart medications to support the function of their heart. These medications do not reverse heart disease. Generally, they slow the progression of heart disease, and patients remain on them for the rest of their lives. In cases of suspected diet-associated DCM, patients on a new diet are eventually able to wean off of medications as their heart function returns to normal. This is completely unheard of in genetic cases of DCM. 
For more owner stories and information on the issue of diet-associated DCM as it develops, consider joining the largest Facebook group dedicated to working with professionals and disseminating evidence-based information on the topic.   

    To return to risk analysis... If one finds themselves questioning whether or not to heed potential risks associated with certain diets, and switch even before a definitive causative mechanism is identified, they need only ask themselves what benefit they believe that the diet they're on holds in the first place. There is zero scientific evidence demonstrating grain-free diets to be superior or associated with improved health outcomes, a fact nutritionists have been pointing out for years.
     While allergies are cited as a common reason for the switch, less than 10% of dogs with  reported allergies have true food allergies, or about  0.2% of all dogs. Of those, allergies to grains are even more rare. Some owners are led to believe that their pet has an allergy to certain ingredients based on blood, saliva, or fur tests for dietary allergies. However, these tests are unreliable and inaccurate. One study even submitted fake samples (tap water, fake fur) and still received a positive allergy report.
     Ingredients such as corn, wheat, and soy are demonized as being "filler" ingredients, but they all contribute protein, fiber, and other dietary essential nutrients to a balanced diet. Corn is a potent source of linoleic acid. Soy, in particular, is comparably digestible to meat ingredients when processed appropriately, and boasts a diverse amino acid profile. Most grain-free diets do not avoid using similar plant-based ingredients (in the form of lentils, peas, and other legumes). However, the latter are poorly researched for inclusion in canine diets, and are now implicated in the development of the present DCM issue.

     The bottom line? There is enough evidence of risk associated with grain free diets to warrant concern, considering that if the risk is actualized, disease may go unnoticed until late stages, and the consequence is death. In the absence of any benefit from accepting that risk, yes, it is worth switching. 

The following resources may be helpful in selecting a new diet:

Infograph - Selecting a Pet Food

World Small Animal Veterinary Association Global Nutrition Committee Recommendations on Selecting a Pet Food

WSAVA GNC FAQ, Myths

The Savvy Dog Owner's Guide to Nutrition on the Internet


Please leave your thoughts, questions, and concerns in the comments! Thanks for reading.
 

Thursday, November 7, 2019

RE: Recent Statements on DCM via PetFoodIndustry

Published Nov 6, 2019, a number of misleading and problematic statements were made regarding the current issue of canine DCM, the role of diet, and the FDA's investigation.

"However, so far, the investigation haven't revealed any evidence for causation between those grain-free dog foods and the onset of the heart disease in dogs."

This is not entirely accurate. The extremely high correlation alone (91% of affected dogs eating grain-free diets, 93% of dogs eating diets with a high amount of legumes and peas) that is not explained away by the prevalence of these diets is indeed "evidence for causation." Additionally, the observance of clinical improvement in dogs that change diet is "evidence for causation." What has not been revealed by the investigation is the mechanism through which the implicated diets influence the heart.

The following statements were quoted from Shawn Messonnier, DVM, a member of the Champion (pet food company) Transparency Council:

"When I talk to clients in my office and they ask me about the DCM issue, I say look, we don't know a thing. Until I know what's going on, all I can say is there are some fearful statements that have been made by the government, here's some foods that some of these dogs were supposedly eating. I don't know if these dogs had DCM or not, but even if the food caused DCM, which would be impossible from a biological perspective, but let's just say somehow it did, you're talking a few hundred causes out of 60 million dogs; this is not even statistically significant to discuss."

This is a lot to unpack, so it has been color coded for ease.
We know several things. We know that cardiologists, board certified specialists, are reporting more DCM cases than they have previously seen. We know that the subsequent FDA investigation has revealed the development of DCM in a variety of breeds, many of them with no predisposition to developing DCM. We know that a disproportionate number of those dogs are eating grain-free and legume-rich diets. We know that a disproportionate number of dogs have been associated with specific niche pet foods that hold a very, very small portion of the market share (< 0.1%). We know that the FDA investigation has ruled out the presence of other known predisposing factors (like tickborne illness) in many of the affected dogs.  We know that dogs improve when changing diet. We know that food has been associated with DCM in the past. 
The FDA has not issued "fearful statements." They've issued an urging for caution among pet owners. The FDA's statements have been carefully mediated, and qualified to express unknowns. Their statements have included "Based on the data collected and analyzed thus far, the agency believes that the potential association between diet and DCM in dogs is a complex scientific issue that may involve multiple factors." and "The FDA is using a range of science-based investigative tools as it strives to learn more about this emergence of DCM and its potential link to certain diets or ingredients." and "The FDA is continuing to investigate and gather more information in an effort to identify whether there is a specific dietary link to development of DCM and will provide updates to the public as information develops."
The pet owners reporting their cases to the FDA know what their dogs were eating. There is no "supposedly" about this issue. These aren't "alleged" diets. On that same note, the cardiologists diagnosing affected animals know whether the dog has DCM or not. 
Perhaps the most egregious of these remarks, this is patently false and demonstrates a meager understanding of the issue at best. DCM is known to have potential dietary cause in the form of taurine deficiency. See here, here, and here. This is well documented and (presumably) widely known within the medical community. Cardiotoxic drugs have also been documented to induce DCM. It is entirely possible from a biological, physiological, or medical perspective that some component of food, whether that be a cardiotoxic compound or a deficit of a nutrient or a nutrient-blocking effect leading to physiological deficiency, contribute to the development of DCM. 
Speaking of things unknown, we do not know how many dogs are truly affected. The FDA explicitly states in their most recent update that for a variety of reasons, dogs are likely not just under-diagnosed, but under-reported. There are no grounds to minimize the reach of companion animals affected by this disease. DCM can progress a-symptomatically, resulting in sudden, unexplained cardiac failure and death. Unless necropsy is pursued, which can be cost-prohibitive and often entails forfeit of a beloved pet’s remains, these cases will never be known. Even when symptomatic, dogs often present with coughing, lethargy, and general malaise, non-specific signs of a myriad of different diseases. They often will auscult normally, with no heart murmur. Diagnosis requires an echocardiogram, an expensive procedure often performed only by cardiologists. Prior to this issue, it would be uncommon to screen a dog without genetic predisposition for DCM. Since the FDA’s announcement, obtaining a diagnosis has only become even more difficult, with many cardiologists booked weeks to months out. There are less than 300 veterinary cardiologists in the US, and they are not distributed evenly, creating geographic disparity in accessibility. It is nearly impossible to put a ceiling on the number of affected dogs, but for anyone who loved one of the 100+ deceased dogs reported to the FDA, even one case of diet-associated DCM is too many.

The next highly problematic statement in the piece comes from Jilliann Smith, director of communications for Merrick Pet Care. She says "We also try to remind them that the FDA is not advising diet changes based on the information gathered so far."

The FDA, as a regulatory body, is not actively advising a diet switch. That does not mean they are actively advising not to switch diet. Instead, they are deferring to veterinarians, and state throughout their updates that owners should discuss the need for a diet change with their veterinarian. Many veterinarians are urging diet changes as a precaution until more information is known. 


PetFoodIndstry, this article, as with many you have recently published on this topic, is disappointing and speaks volumes to where the heart of your journalism lies. Please reconsider the direction your publications are taking. 


For more reading on DCM and the FDA's investigation, see:

The FDA's Update (June 2019)
Diet-associated dilated cardiomyopathy in dogs: what do we know?
FDA searching for possible links between canine diets, heart disease
It’s Not Just Grain-Free: An Update on Diet-Associated Dilated Cardiomyopathy

Is Big Business Truly Behind the DCM Debacle? The Demand for Sound Science
What Do Vets Really Know About Nutrition, Anyway?


Thursday, October 24, 2019

Is Big Business Truly Behind the DCM Debacle? The Demand for Sound Science


As many pet owners are now painfully aware, last July the FDA announced an investigation into a purported association between dilated cardiomyopathy (DCM), a deadly disease of the heart, and grain-free commercial diets. This investigation began at the behest of veterinary specialists who perceived a recent spike in cases of DCM in breeds not typically expected to develop it.
This June, the FDA released a major update, controversially providing the names of brands with 10 or more reported cases. While cases from veterinarians span back as far as 2014, the FDA states in their update“ the vast majority of the reports were submitted after the agency notified the public about the potential DCM/diet issue in July 2018.” In total, as of April 30, 2019, over 500 cases had been reported. Since that update, the situation has reached new levels of publicity, spanning across major news networks and garnering the attention of pet professionals everywhere. Amidst all this, a common thread seems to remain: conflicting information and confusion.
July of this year, a claim began circulating that poor methodology, undisclosed financial interests, and ultimately, ‘Big Pet Food,’ are behind the unwarranted attention to the issue of grain-free diets and canine DCM. In particular, question was called to the JAVMA article “Diet-Linked Dilated Cardiomyopathy: What Do We Know?” At the root of this claim lies Mr. Daniel Schulof, lawyer by trade, pet food writer by choice, and CEO of KetoNaturals pet food, a diet formulated primarily with pea protein, an ingredient implicated in 89% of the FDA’s reported cases. Citing financial damages to his company as motivation, Mr. Schulof has sent a 42 page letter to JAVMA requesting retraction of the article mentioned above. While compelling, how valid is his case? Considering his own financial interest in protecting a company that falls within the radar of DCM scrutiny, it seems worthwhile to approach the claims critically. This is a long article, so strap in.
Myth: More than 200 veterinarians, animal scientists, and ‘other stakeholders’ co-signed the retraction package to JAVMA
Only 9 veterinarians, a few of them unnamed, signed. None of them were boarded nutritionists. 3 non-veterinary animal scientists signed, 14 non-veterinary medical professionals, and 14 representatives of ‘BEG’ pet food companies. All other co-signers fell into the category ‘other.’ Some of these ‘other’ identified themselves as pet owners, dog breeders, or owners of independent pet food retail shops. The vast majority did not identify a profession or a stake.
Myth: There is actually no evidence that canine DCM is associated with ‘BEG diets,’ ‘grain-free diets,’ or any specific ingredients.
There is currently strong evidence of a correlation (or association) between certain diets, ingredients, and DCM. Research uncovering a causative link, if there is one, is currently underway. In the FDA report, 91% of the dogs were consuming grain-free diets. 93% were consuming a diet high in legumes and peas. Considering the relatively lower market share of these diet-types and ingredients in the US, such atypical numbers are undeniably a correlation. In light of that observed correlation, numerous universities across the US are now conducting research to discern what, if any, causative factors are underlying the correlation. It is worth noting that many veterinary cardiologists are reporting clinical improvements in DCM patients that change diet following diagnosis, even in the absence of other medical intervention. Reversal has also been seen in dogs reliant on heart medications that are then able to be weaned off following diet change. While it may seem reasonable to blame medications for that improvement, in genetic forms of DCM reversal is not seen, even after months of medication, as they function through supporting, not healing, the heart.
Vet-LIRN has found that only 9% of dogs had hypothyroidism (a risk factor for DCM) and just 8% had a history of tick-borne disease (with Lyme exposure also being a DCM risk factor). Heavy metal and narcotic exposures have been inquired about, and DNA samples have been collected from affected dogs to try and discern if there is a genetic component. To date, the most significant, consistent association common to the affected dogs remains diet.
Myth: Very few dogs have developed diet-mediated DCM.
The FDA explicitly states in their most recent update that for a variety of reasons, dogs are likely not just under-diagnosed, but under-reported. There are no grounds to minimize the reach of companion animals affected by this disease. DCM can progress a-symptomatically, resulting in sudden, unexplained cardiac failure and death. Unless necropsy is pursued, which can be cost-prohibitive and often entails forfeit of a beloved pet’s remains, these cases will never be known. Even when symptomatic, dogs often present with coughing, lethargy, and general malaise, non-specific signs of a myriad of different diseases. They often will auscult normally, with no heart murmur. Diagnosis requires an echocardiogram, an expensive procedure often performed only by cardiologists. Prior to this issue, it would be uncommon to screen a dog without genetic predisposition for DCM. Since the FDA’s announcement, obtaining a diagnosis has only become even more difficult, with many cardiologists booked weeks to months out. There are less than 300 veterinary cardiologists in the US, and they are not distributed evenly, creating geographic disparity in accessibility. It is nearly impossible to put a ceiling on the number of affected dogs, but for anyone who loved one of the 100+ deceased dogs reported to the FDA, even one case of diet-associated DCM is too many.
Myth: The veterinarians at the heart of the DCM investigation are financially tied and beholden to Hills, Mars, and/or Nestle-Purina.
The particular individuals under fire with this claim are Dr. Lisa Freeman, Dr. Joshua Stern, and Dr. Darcy Adin. The first contention is that they all work for research universities that receive donations from Hills, Purina, and Royal Canin. If one excludes all research out of research universities as invalid due to financial interest from corporate donations, there would be very little research left in the world. The researchers are not beholden to any of the corporations that have donated, past or present, to the university under which they are employed. More information on corporate funding is provided later in this piece.
Dr. Lisa Freeman disclosed her potential conflicts of interest in the JAVMA article. “Within the past 3 years, Dr. Freeman has received research support from Aratana Therapeutics, Nestlé Purina PetCare, and Royal Canin; has consulted with Aratana Therapeutics and Nestlé Purina PetCare; has given sponsored talks for Aratana Therapeutics, Hill’s Pet Nutrition, and Nestlé Purina PetCare; and has served on a scientific advisory board for Aratana Therapeutics.”
Dr. Adin did the same. “ Within the past 3 years, Dr. Adin has received research support from Nestlé Purina PetCare.”
These authors are not receiving an ongoing salary from these companies, nor do they necessarily stand to gain additional future funding or support if Purina or Hills or Royal Canin continue to grow as companies. One would be hard pressed to find research experts in any field who have never received financial support from companies or corporations invested in that field. That is why it is standard to disclose such connections and important to critically evaluate methodology and obtain peer-review for any scientific studies.
Myth: The leading academic article about DCM, published in JAVMA, was done so under the guise of peer-review, while in fact circumventing the peer-review process entirely.
The article, published in the commentary section, was not published as a peer-reviewed study. It was not presented as a meta-analysis, does not contain an abstract, and was at no point presented as research. As a commentary, the article is an opinion piece — it presents the opinion that the potential underlying diet-mediated cardiomyopathy is concerning and warrants vigilance. It also emphasizes the opinion that marketing has outpaced the importance of evidence and science in the field of pet nutrition. The summary of the article reads (emphasis added): “Pet food marketing has outpaced the science, and owners are not always making healthy, science-based decisions even though they want to do the best for their pets. The recent cases of possible diet-associated DCM are obviously concerning and warrant vigilance within the veterinary and research communities. Importantly, although there appears to be an association between DCM and feeding BEG, vegetarian, vegan, or home-prepared diets in dogs, a cause-and-effect relationship has not been proven, and other factors may be equally or more important. Assessing diet history in all patients can help to identify diet-related cardiac diseases as early as possible and can help identify the cause and, potentially, best treatment for diet-associated DCM in dogs.”
The authors made it no secret that there are significant, glaring gaps in our current knowledge. Despite that this is a commentary, however, the opinions presented were bolstered with facts, hence “What Do We Know.” The article cites 33 outside sources and clearly details what was previously known about DCM, what findings are emerging, and what concerns are now present.
Additionally, despite being published as a commentary piece that is not obligated to undergo peer review, this particular piece still may have. On the supplemental materials page corresponding to the article, the following text can be found: “ This supplementary content was made available to the external peer reviewers at the time of manuscript review.” While the text may be included in an automated error, as most commentaries do not include supplementary materials, the only way to confirm that peer-review was not undergone is to contact JAVMA directly. This article will be updated to reflect any new information on that front. Regardless, the piece underwent editorial review before publication and the nature of the content does not necessitate peer-review.
Myth: Recent studies on DCM have had serious, unaddressed methodological problems.
Recent studies on nutrition-related DCM are limited, as has been openly admitted by both advocates for the rising concern and dissenters alike, but do not have the “serious flaws” purported.
retrospective analysis, published in Feb 2019, found differences between nutritional and genetic forms of DCM. As a retrospective analysis, this study relied on information, such as diet history, that had already been obtained as part of the clinical evaluation, before the undertaking of the studies. For reasons like this, retrospective studies are inherently limited and serve primarily to identify areas of future clinical research. The authors highlight these limitations in their discussion. Mr. Schulof’s primary contention with this study is that the final published data do not match data given in a preliminary form of the study presented during an earlier conference. He states that correspondence with Dr. Adin, one of the authors, confirmed that the reason behind the change in data was a re-evaluation of the available diet histories. This is a very common occurrence in research. Abstracts for conferences are submitted well in advance, and research papers undergo extensive editing and review before final publication. The conference itself presented an opportunity for other professionals to assess the methodology and point out an issue such as inconsistency in inclusion criteria. He discusses the odds of this occurring by chance to be “less than 1 in 10,000.” However, this decision was not made by chance, with random cases excluded without reason. The decision was made by analysis of available data against a set of inclusion criteria. The authors note “This study had several limitations inherent in its retrospective design. The presence of a detailed diet history was inconsistent in our medical records during this study period, which reduced the number of included dogs and could have introduced bias.” To be more specific, it is possible that clinicians are biased to conduct a more extensive diet history with owners feeding a grain free diet, and that bias could subsequently result in more grain-free fed dogs available for analysis retrospectively.
Contention with the second study lies in regards to the involved diets not being tested for their amino acid profiles. While it may be the case that the underlying cause of the taurine-deficiency noted was amino acid deficiency in the diet, that does not absolve grain-free or legume-containing diets of association. In fact, it would only serve to indicate that there is indeed an observable dietary deficiency in those formulations, despite being marketed as complete and balanced. Contrary to some claims, this possibility was not ignored by the authors of the paper. They clearly state: “ Ideally, amino acid concentrations in the diet, especially taurine, methionine, and cystine would be obtained to determine if diets were deficient in any of these essential ingredients. However, this data was not made available by the diet manufacturers. Further research is needed to better understand their characteristics before any additional conclusions can be drawn.”
Myth: Independent analysis has shown that sulfur-containing amino acid deficiency is to blame, not grain-free and not peas or legumes.
Mr. Schulof took it upon himself to analyze pet food formulas involved in a golden retriever study on DCM, many of which were from brands also over-represented in the FDA case reports. While his provided analysis claims low levels of methionine and cystine, the FDA’s own analysis of the foods came up different. Dr. Jennifer Jones with Vet-LIRN at the FDA stated that of the tests conducted on involved dog foods collected from homes and stores, only two products came back abnormal. The tests included free and total amino acid profiles.
Even if one assumes that the analysis reported by Mr. Schulof is more reliable or reputable, it still does not offer much information other than that there is a problem in formulation with grain-free and legume-focused diets. These are all diets marketed as complete & balanced. If they are deficient in essential amino acids, that is a big problem. If it is happening disproportionately in certain formulations, it is an indication that those ingredients may need special attention to ensure deficiencies don’t occur, as in lamb & rice diets.
It is also worth considering that reputable and responsible pet food manufacturers test their final physical products (not just the formulation) for nutritional adequacy. Furthermore, even when a nutrient is present, it is not always in a form with adequate bio-availability, underscoring the importance of long-term feeding trials and testing of animal blood values, not just analysis of the product.
Myth: Dogs have not been shown to improve with diet-change alone, because many receive taurine supplementation and heart medications.
First and foremost, dogs diagnosed with genetic forms of DCM do not show improvement, even with months of heart medications. That is because the medications function by supporting heart function, not healing damage to the heart. Some have called to question the documented improvements of dogs in the studies referenced above, as the dogs were receiving taurine supplementation in addition to a change in diet. While it is true that dogs have been documented to show improvements in DCM when receiving taurine, that is only when taurine-deficiency was the cause of the DCM development. In regards to the current FDA investigation, affected dogs have tested low, normal, and high for serum taurine. The dogs in Dr. Adin’s referenced study were not taurine-deficient, and therefore taurine alone would not be expected to create clinical improvement. The authors note the following: “ While it is difficult to draw conclusions from low case numbers, the single dog that did not receive taurine supplementation showed minimal echocardiographic improvement at 3 months but did improve 9 months after diagnosis, potentially suggesting slower improvement compared with dogs that were supplemented with taurine. Variability between dogs may also account for this slower improvement.”
Even beyond published literature, cardiologists across the US have reported to media and at conferences that they have seen clinical improvement among their patients even in absence of any medications or taurine alongside the change in diet.
Myth: This is a US-exclusive concern.
This trend was first recognized in the United States. That does not mean it is occurring exclusively in the US. Veterinary groups in other countries have released statements on monitoring the FDA investigation as it develops, and cases of diet-related DCM have been reported among international veterinary circles. Dr. Ryan Fries, a veterinary cardiologist and head of the cardiology department at University Illinois, has surveyed veterinary cardiologists internationally on DCM cases suspected to be nutritionally-mediated. He received responses from not just the US, but UK, Canada, Israel, and Austria. The results are not yet published, but were mentioned in the JAVMA article he co-authored.



If you’ve made it this far, surely you’re left to wonder — what DO we know?
Fact: Grain free diets, diets high in legumes or peas, and diets containing exotic ingredients are disproportionately associated with unexplained DCM across numerous breeds and we do not know why.
That the current cause is unknown is a call for caution, not complacency. In 2001, a similar piece to the one regarding DCM was published in JAVMA as a letter to the editor. It concerned preliminary evidence that raisins and grapes may be associated with acute renal failure in dogs. To date, it is still unknown what substance in grapes induces renal failure in some dogs. The toxic threshold is unpredictable, and many dogs have been observed to eat grapes their entire lives with no ill effects, while other dogs have gone into kidney failure and passed away after ingesting only a small number of them. Despite having only an association noted, even nearly two decades later, the ingestion of any amount of grapes or raisins is treated as a medical emergency. With no way of knowing whether a given dog will be hypersensitive and experience toxic effects, the risk is mitigated by avoiding grapes. The consequence of not providing treatment (emesis of the ingested grapes) to an animal that turns out to be sensitive to grapes is death. The consequences of not giving dogs grapes? Virtually non-existent.
Likewise, with no way of predicting what other factors are at play with the development of diet-associated DCM, the risk is mitigated by avoiding the known risk factors — grain-free formulations and formulations with significant legume / pea content. The consequence of not providing treatment (in this case, a change of diet) to an animal that develops nutritional DCM on is death. The consequences of avoiding grain-free diets and peas and legumes until more is known? Virtually non-existent.
Fact: To date, there is no evidence demonstrating that grain-free diets are necessary, or even beneficial, for dogs.
The literature simply is not there. The most oft cited reason for going grain free is mitigation of allergies. However, the most common allergies in dogs are seasonal and environmental. Of the small percentage that are dietary, chicken and beef are by far the most common culprits. For the very limited number of dogs with a true allergy to a grain, it is typically only to that one grain, not all types of grains. These dogs typically require hypoallergenic diets prepared in facilities designed to prevent undisclosed protein contamination.
Fact: There is no reason to suspect motivation within ‘Big Pet Food’ to demonize or otherwise scheme against raw, natural, grain-free, boutique, exotic, or any other niche formulation-type pet food manufacturers.
Nestle’s revenues are on the rise and they have attributed the growth to their petcare sector, Purina. They produce and sell both grain-free and natural lines.
Hills can say the same. While Royal Canin does not offer any OTC grain-free diets, they too have continued to experience company growth.
These companies are not threatened by the popularity of smaller manufacturers. If they were, they all have the funds and technology available to them to market niche formulations that appeal to changing trends in pet owner preferences and beliefs. They have more than enough financial ability to run extensive marketing campaigns to improve PR. Any scheme to paint grain-free formulas in a bad light would only backfire on themselves as well, as they carry grain-free lines. From a business perspective, they are more threatened by one another than other much smaller manufacturers.
These companies do frequently offer research grants and sponsor veterinary conferences. Every pet food company should do this — it shows that they are both principally and literally invested in the health and care of their primary consumers, your pets. Research is conducted to get answers that reflect reality, not provide results that cater to corporations. Some researchers do not even know where the funds for the research they’re conducting originated until after it is done. While it is always possible for malfeasance to occur, processes like peer-review are in place to mitigate risk of bias, and researchers are mandated to disclose any potential financial conflicts that could be construed. Critical examination is warranted, but we cannot presume that every study partially funded by a grant from a corporation was swayed in that corporation’s favor (more reading here and here). Colgate offers grants for dental research. It is common for companies to invest in research relevant to their field, so that they can innovate and reflect the newest findings. Extra caution should be exercised when evaluating evidence from studies funded by sources that may sway results, but that does not mean the findings should be unanimously dismissed from the start. In this particular case, it is neither here nor there, as the FDA is a government agency conducting an investigation and receives no funding from corporate sponsors.
Purina, Hills, and Royal Canin have traditionally been recommended by veterinarians, and in many cases, continue to be. This has led some to suspect foul play and lined pockets, but the reality is that veterinarians receive extensive, non-sponsored education on nutrition as part of their curriculum. These brands are recommended by professionals because they conduct, publish, and fund extensive research in nutrition, have top notch quality control procedures, and formulate their diets under the directives of large teams of experts including veterinary nutritionists. Vets are not paid money to feed or offer or recommend any specific diets. But, say they were? Imagine for a moment that you were offered by a company to get paid to feed your pets their food. If you had any suspicion that the food was less than ideal for your pet, would you do it? If the answer is no, consider why you believe your veterinarian would do any different, even having devoted their life and education to animal healthcare.
Fact: Your veterinarian, not any other pet professional, is your best source for accurate information regarding canine nutrition, particularly as it pertains to your individual animal.
As stated above, contrary to common myth, most veterinarians have received extensive medical training in nutrition, alongside other core topics like cardiology, surgery, and anatomy. While specific curriculum varies by school, a good grasp of nutritional sciences is necessary for understanding many disease processes that are mediated by nutrient deficiencies or excess. Nutrition is considered the fifth vital sign for small mammals, alongside temperature, pulse, respiration, and pain assessment. Every vet is expected at graduation to be competent in nutrition assessment. For more complex issues, there are nutrition specialists, certified through the American College of Veterinary Nutritionists. Just as your regular vet is capable of providing basic surgical services to you, with boarded surgeons reserved for severe illness, injury, and congenital defects, your regular vet is fully qualified to offer basic nutrition information to you, such as what to feed, how much to feed, and how diet can impact health with boarded nutritionists ideal for consult in formulating a home diet or addressing unique dietary needs.



This issue is frustrating. It is daunting, scary, and it is confusing. The ease with which false or misleading information can be disseminated these days is alarming and the constant push to triple check everything is exhausting for even the most scholarly among us. Finding a trusted network of reputable resources is invaluable. Request sources, inquire about credentials, and do not allow anyone to demand you take information at face value or allegation alone. With time, the age of shouting “fake news!” and pointing fingers at opposing positions will pass, and intellectual clarity will be regained. Until that time, do your due diligence. We owe it to ourselves to stay well-informed, but more than ever, we owe it to our pets, who cannot do it for themselves.

Wednesday, July 10, 2019

What Do Vets Really Know About Nutrition, Anyway?

     As pet owners, we constantly face an onslaught of contradictory information regarding what's best for our pet's health and well-being, complicating the pursuit of making informed decisions. Perhaps no topic is more egregious than that of nutrition, where the wealth of misinformation has grown so tall, people have become wary of trusting even the input of their veterinarian. Many companies have pursued marketing tactics that de-legitimize the words of licensed and boarded experts, hoping to sway owners against research-backed formulas in favor of new fads and bold claims. They say that vets don't receive any training in nutrition, and that they're told to simply recommend the big brands. This may leave one to scratch their head and wonder-- what does my vet really know about nutrition, anyway? Did she even receive formal education on the topic? Does he know the first thing about evaluating ingredients?

     The truth is, most veterinary schools in the US have a wonderful nutrition curriculum, over half employ a boarded American College of Veterinary Nutrition diplomate, and veterinary students enroll in both required and elective nutrition courses. The curriculum requirements for a veterinary college to be considered accredited in the US are stringent, and include providing "an understanding of the central biological principles and mechanisms that underlie animal health and disease from the molecular and cellular level to organismal and population manifestations," and "knowledge, skills, values, attitudes, aptitudes and behaviors necessary to address responsibly the health and well-being of animals in the context of ever-changing societal expectations." One of the 9 competencies expected of all US graduates is "critical analysis of new information and research findings relevant to veterinary medicine," meaning that even in regards to the ever-changing nature of medicine, a veterinarian must be capable of interpreting and reviewing research findings.

     There should be no doubt that nutrition is considered to be medically pertinent by the veterinary profession as a whole. The World Small Animal Veterinary Association (WSAVA) has provided guidelines for nutritional assessment since 2011. The association maintains that nutritional assessment is one of the five vital signs to be evaluated in the basic physical exam of all small mammals, along with temperature, pulse, respiration, and pain assessment. The 12 page document guides the practitioner through conducting a thorough assessment of the animal's nutritional status and ongoing needs. This document does not provide any specific food or brand recommendations for veterinarians to provide their clients, but instead offers criteria for consideration during commercial diet evaluation. The American Animal Hospital Association (AAHA) has also provided similar guidelines, likewise asserting that nutrition is an integral part of animal health and wellness. Finally, the American College of Veterinary Nutrition (ACVN), established by the American Academy of Veterinary Nutrition (AAVN) in 1984 to develop nutrition as a boarded specialty, has published a document of nutritional competencies of small animal veterinarians, a list of functions that all small animal vets should be able to perform upon graduation, even without specialization. The three page list of competencies includes:

  • Determine adequacy of the current diet for the physiological status of the animal
  • Understand the functions of nutrients and the role of ingredients and nutrients in health and disease
  • Differentiate between the presence of diet-induced and nutrient-sensitive disease
  • Provide assistance to formulate an adequate home-prepared diet when necessary, referring to ACVN Diplomate as needed
  •  Assist the client in choosing appropriate diets for their pet’s lifestage, activity and physiology, consistent with the client’s personal preferences
  • Evaluate nutrition-related information presented in journals and other professional texts
  • Evaluate validity of nutrition-related marketing claims

     Though it should be clear that there is an expectation for nutrition knowledge within the profession, curriculum and competencies are just on paper-- what about a first hand account of what happens behind closed classroom doors? To recount my own first year introductory nutrition course: 

Our classroom was not sponsored by Nestle or Mars. I paid approximately $900 in tuition for this single course. Some of my out of state colleagues paid closer to $1400. Our professor was not some random marketing rep from a pet food company. He’s a faculty specialist at the campus veterinary hospital. He’s boarded in not only nutrition, but also internal medicine. In addition to his veterinary degree and specializations, he holds a Master’s in medical science and a PhD in veterinary medicine. 

Among other objectives, we were expected to learn the following:
  • Macronutrients, their role in the diet, their sources, digestibility / quality between the sources, and results of deficiency and excess
  • Micronutrients, their role in the diet, their sources, bioavailability differences between sources, combinations of ingredients that can limit their bioavailability, and medical conditions, activity levels, and other factors that increase or decrease the amount of those nutrients needed in the diet
  • How to evaluate a nutrition label and mathematically determine the calories attributable to each macronutrient 
  • What factors alter the metabolism and therefore caloric needs of dogs and cats
  • Laws that govern the pet food industry and gaps in legislation that leave certain aspects unregulated
  • What factors impact palatability
  • Differences between dry, moist, cooked, and raw diets
  • Nutritional needs for puppies, kittens, pregnant and lactating bitches and queens
  • Ways to determine digestibility, factors that alter digestibility, and average digestibility of common protein and carb sources
  • The role of the colon microbiome in the digestion of insoluble fibers

We studied dogs, cats, horses, and both beef and dairy cattle needs extensively. We also had a summarized unit on small species such as rodents and rabbits. If we choose to pursue it, a later elective course on exotic nutrition is available. 

We had to sit down and formulate a homemade diet that was complete and balanced to meet all essential dietary for a dog. We weren’t allowed to leave the lab until we had a recipe that worked, within 10% of all the nutrient needs. It took most of us several consecutive hours. 

We had to do a 5 page write up on our own pet’s food and discuss all the individual factors that affect our specific pet’s nutritional needs, such as activity, age, breed, any pertinent disease states, and even the temperature at which we keep our house or apartment.

This is just a summary of what the course entailed- it was by no means a walk in the park. It was an intense, rapid-fire, in-depth course on animal nutrition, and considered only a basic introduction to the subject. 

     So what of the well-perpetuated myth of payoffs and kickbacks from the major companies? We do have sponsored lunches at the vet school-- Purina most frequently hosts these, and one of the veterinarians (not a marketing representative) that works for the company gives a lecture on one of their products. These lectures do not consist of a sales pitch for Purina diets. Instead, they're usually a summary of the company's most recent research on a specific prescription diet. Last year, we had a lunch lecture about the Overweight Management diet, which focused first on a discussion of obesity as a problem in pets, and second on what research was conducted by Purina to substantiate the effectiveness of their prescription food. We also had a lunch lecture on their new probiotic product, Calming Care, where an overview of the research conducted on BL999 bacterial strain for the treatment of anxiety was discussed. 
     These lectures are important. They allow young veterinary professionals to be exposed to marketing early in their career and learn how to critically analyze a product, the research backing it, and assess how it stands up to competing products. They are not presented with the intent of swaying students to favor one brand or another. In fact, the American Association of Veterinary Medical Colleges has published in their policies and procedures manual (pages 36-39) "Guiding Principles and Consideration: Ethical Interactions Between Schools/Colleges of Veterinary Medicine and External Entities" to help mediate the potential for bias introduction during these sponsored events. 

     Similar lectures are sometimes offered as "Lunch & Learn" Continuing Education (CE) for veterinary clinics. These lectures are also offered by drug representatives (manufacturers of vaccines, prescription drugs, and nutraceuticals), surgical tool representatives, laboratory analytical device representatives (such as IDEXX and Abaxis, who sell products for in-house blood work) and various other retailers of products pertinent to the practice of veterinary medicine. These lectures provide an advertising avenue for these companies, yes, but also allow veterinary professionals to utilize their education to critically evaluate the products being offered to them. Veterinary medicine cannot be practiced in a vacuum-- there are tools required for the trade, some of those tools are products, such as foods, drugs, and devices, manufactured by third party companies, because the role of the veterinarian is a health care provider, not a manufacturer. 
     As medical professionals, it is not the job of a veterinarian to blindly accept any product marketed towards them. Rather, they utilize their educational background to critically evaluate what products are the best solutions for their patients, based on research and a scientific foundation. Things like prescription diets are not money makers for the practice. Veterinarians are not the profiteers of the pet food industry. While diets may be offered at a discount to a clinic that opts to regularly stock them, this discount is often passed on to the client, for the sake of convenience. Even with a mark-up, the profit margins for pet foods in a clinically setting is notably low. More money can be made off of a routine toe-nail trimming than selling a bag of food.  


      For more on this topic, check out "Are Vets Bought by Big Pet Food?"

     Now, all of this is not to say that every single veterinarian is an expert on nutrition. There are  certainly veterinarians that don't feel comfortable discussing nutrition with clients, and others who have become emotionally exhausted with the task and have decided that it is not worth the struggle of arguing with clients that are convinced that they know better. However, by all current field standards, nutritional assessment is considered part of a basic exam that all veterinarians should be competent in conducting. If your vet is comfortable discussing nutrition with you, you should feel confident that the advice they have to offer is more sound and educated than the advice offered by a breeder, pet enthusiast, trainer, or feed store employee. 


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Are Vets Bought By Big Pet Food?

     In light of the recent FDA investigation into dietary DCM in dogs, the age old concern that veterinarians are bought and paid off to recommend "Big Pet Food" (Nestle Purina, Mars (Royal Canin, Eukanuba, Iams), and Hill's) has returned with a vengeance.

     The reality is, vets recommend those brands because they are, unlike many offered across the US, heavily research-backed and evidence-based. The companies employ experts (Diplomates of the American College of Veterinary Nutrition, PhD scientists with focuses in Animal Science, Nutrition, Toxicology, etc) to formulate and evaluate their diets. They conduct extensive feeding trials that exceed AAFCO minimums before releasing new formulations to the public. They conduct and invest in research, then proceed to have that research peer-reviewed for bias and published in scientific journals for other companies and professionals to reference and utilize. These brands are the only ones offered in the US that meet the highest standards for all of the recommendations made by World Small Animal Veterinary Association Global Nutrition Committee.

     While concern has been expressed that some WSAVA events and conferences have been sponsored by Mars and Nestle, these guidelines are nonetheless impartial and non-exclusionary. WSAVA does not certify or approve or endorse any manufacturers for meeting these recommendations. They provide the recommendations for owners and veterinarians to utilize on their own for evaluation of any given manufacturer. 

  1. Companies should employ experts. Employing multiple experts is better than a single expert, which is better than consulting with an expert, which is better than not involving an expert at all. Companies should be transparent and be able to name their nutritionist and provide their qualifications and credentials. 
  2. The individual(s) formulating diets should be well-credentialed and qualified to be doing so. 
  3. All foods should meet AAFCO standards for complete and balanced. Meeting that standard using feeding trials is preferable to formulation or analysis alone. Feeding trials should be conducted on all or most formulas, not simply a select few.
  4. Food should be produced and manufactured in a clean, monitored facility. Companies should be willing to disclose information on where their product is made.
  5. Companies should be able and willing to describe their specific quality control measures.
  6. Companies should be able and willing to provide a complete nutrient analysis for their food. 
  7. Companies should be able and willing to provide the calories per gram of their products.
  8. Companies should conduct research and publish that research in peer-reviewed scientific journals. 
     All pet food manufacturers should be striving to meet high standards for each of these recommendations. Currently, only the "Big Food" brands are doing so. 

     It is also true that Nestle, Mars, and Hill's provide research grants and scholarships to veterinary professionals and students. They also sponsor conferences for continuing education. Its important to note that the sponsorship does not mean that marketing reps get to give lectures about why their food should be sold, nor does it indicate an agreement to recommend or sell that brand. Instead, it usually means that employees get discounted conference attendance, and the company gets a booth in the conference's product hall. Medicine cannot be, and never will be, practiced in a vacuum. Practicing vets cannot craft their own surgical instruments, engineer their own blood analysis machines, build their own clinics, chemically formulate their own pharmaceuticals, or, most relevant in this case, manufacture their own lines of companion animal diets. Part of the medical professional's job is to critically evaluate the goods advertised to them, and be discerning consumers in order to provide the best for their clients. If those goods are created by companies that employ professionals, they are more likely to meet the high standards that the discerning practitioner is looking for. 
     
     These companies unabashedly support the veterinary medical community, but one should critically ask themselves why that would be considered a bad thing. The profits of these companies are quite literally invested in animal health and the professionals that take an oath to protect it. Where are the profits of other companies going, and why do those companies not support veterinarians?

     None of the support offered by these companies (which is never in the form of 'kickbacks') changes that they are strongly backed by research, science, and decades of commitment to animal health. That is why they are recommended. 

Thursday, March 21, 2019

The Facts & Fiction of Pet Food - Raw Diets


The Facts & Fiction of Pet Food 


About Raw Feeding

As the human-animal bond continues to blossom, and our pets become more and more a part of our families than the past, people are putting more effort into optimizing care for their animal companions. While this is nothing short of great news, unfortunately it has created a marketing niche for misinformation to be spread and utilized to sway people towards certain products. While there is no question that proponents of raw feeding are only trying to do the best by their furry friends, there is a myriad of myths circulating in the media regarding the purported benefits and lack of risks to raw feeding. This post is intended to clarify some common reasons people opt for raw and provide clear facts on the issue so that everyone is equipped to make informed decisions.

"Wolves eat raw!"

While it's true that wolves and other wild canines naturally consume raw meat, there are a plethora of reasons why this is not an ideal standard for our domestic canine companions. First and foremost, dogs are not wolves. When comparing full genomic sequencing, there are at least 36 regions of variation that have been subject to significant selective alteration in domestic dogs. Of these, ten play key roles in digestion and food metabolism. The authors of this particular study concluded a genetic predisposition for the improved ability to digest a starch-rich diet is present in domestic dogs when compared to wolves.

It is also worth note that behavior and diet in the wild is very much driven by what is available for immediate survival, not necessarily by what is most conducive to long-term health and an extended lifespan. While wolves in the wild typically live 6 - 8 years, dogs and captive wolves have an average lifespan of 10 - 13 years.

Even if one were to hold that the domestic dog's diet should mirror that of their wild counterparts, most raw diets are not as fresh as the carcass eaten by wolves after a kill. In most cases, muscle tissues harbor little, if any intrinsic bacteria. That is, most bacteria is introduced to meat during and after slaughter. Processing not only allows for the introduction of novel bacterial pathogens to raw meat, it also provides the time and environment for those organisms to multiply. While this poses an issue for the surface of whole cuts, it is an even greater concern when considering ground meat, all of which is exposed to external contamination.

"Raw doesn't pose a health concern. I handle it appropriately and dog's digestive systems are protected from the bacteria in raw meat."

Generally speaking, humans are more susceptible to food-borne illness than most other animal species. However, that does not mean that dogs are immune. As discussed above, dogs differ substantially from wolves and even still, meat that goes through production is exposed to pathogens that would not be present in a freshly killed specimen. In nature, a canine would not be subject to the food-borne pathogens present in raw meat products. Of prominent concern are SalmonellaE. coliListeria, and Campylobacter. Not only can dogs become ill from exposure to these organisms, all of these diseases are zoonotic as well, meaning they can be passed on to people. Raw diets are known to harbor these bacteria, and dogs fed raw diets shed these bacteria in their saliva and feces. Even when handling raw products with safety in mind, both dogs and their owners are at a greater risk of pathogenic bacterial infection where raw food is involved.

More concerning, emerging evidence links raw pet food diets to antibiotic resistant bacteria.

The best solution to this problem is to cook any fresh diets offered to pets, which brings up the next major topic:

"Cooking food removes important nutrients. Raw diets are far better for balanced nutrition."

Cooking food has a variable effect on digestibility and nutrient content. While cooking, and in particular, processing, meats does tend to reduce the digestibility of the proteins, the effect is moderate at best and the clinical implications have not been thoroughly investigated. In one study it was found that while a raw diet offered greater digestibility than a dry kibble diet, cooking the raw diet prior to feeding did not impact the digestibility or nutrient profile. For plant-foods, cooking can actually significantly increase the bio-availability and digestibility of the food.

That said, most raw diets are not appropriately balanced to provide adequate long-term nutrition. A 2011 study in Germany found that of 95 assessed raw diets, 60% were nutritionally deficient. A 2013 evaluation found that over 180 assessed diets, representing over 80% of the sample, were nutritionally deficient in multiple categories.

"My pet's health is so much better on raw!"

It is common for people to report subjective health improvements noticed after switching to raw foods. Improved coat appearance, particularly shine and texture, is of particular importance to owners when self-reporting on perceived animal health. This can likely be attributed to the higher fat content of raw diets when compared to traditional pet foods, which results in these desired changes to the coat. Despite these perceptions, however, there is no published literature on the health benefits of feeding a raw diet over a cooked or kibble diet. In some cases, the perception of health improvement may be the result of a placebo by proxy, and in others, the perception may reflect an actual improvement in health due to a diet change. However, the same improvements could likely be replicated with a cooked diet which would provide the same nutrients with less risk of creating health concerns.


Formulating an at-home diet

People pursue a raw diet wanting to do the best by their pet. This is not disputed. Unfortunately, raw is likely not the best option for many of our furry companions, despite a wealth of misinformation circulating the media. While many kibble diets exist that are sufficient for maintaining health and well-being, a fresh, nutritionally-balanced, cooked diet is still ideal whenever people have both the finances and time to pursue providing it. That said, it's important if you wish to cook your pet a diet at home, you consult with a board certified veterinary nutritionist to develop a diet that is complete and balanced to meet your pet's needs.

Positions of Veterinary Organizations on Raw Feeding

"RMBDs have a high risk for contamination with bacteria, parasites, and other pathogens. In addition to the risks of nutritional inadequacy and contamination with bacteria and parasites, other health concerns for an animal eating a RMBD include risks from ingestion of bones if they are included (e.g., constipation, diarrhea, dental fractures, gastrointestinal obstructions) and diet-induced hyperthyroidism from excessive ingestion of thyroid tissue. There is currently no properly documented evidence of health benefits for RMBD, but there are well documented risks. As such, the World Small Animal Veterinary Association Global Nutrition Committee recommends that RMBD not be fed to dogs and cats."

"The Canadian Veterinary Medical Association (CVMA) accepts the evidence for potential health risks to pets fed raw meat-based diets (RMBDs), and to humans who are in contact with RMBDs, or with pets fed RMBDs. The CVMA holds that the documented scientific evidence of potential animal and public health risks in feeding RMBDs outweighs any perceived benefits of this feeding practice."

"The AVMA discourages the feeding to cats and dogs of any animal-source protein that has not first been subjected to a process to eliminate pathogens because of the risk of illness to cats and dogs as well as humans."

"Past proponents of raw food diets believed that this was the healthiest food choice for pets. It was also assumed that feeding such a diet would cause no harm to other animals or to humans. There have subsequently been multiple studies showing both these premises to be false. Based on overwhelming scientific evidence, AAHA does not advocate nor endorse feeding pets any raw or dehydrated nonsterilized foods, including treats that are of animal origin.`"

"At this time, the vast majority of purported benefits of feeding raw foods remain unproven, while the risks and consequences have been documented. It is best to discuss the choice of feeding raw foods with your veterinarian so that an informed decision can be made with regard to your pet’s diet."

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Thanks so much for reading!! I strongly encourage you to leave comments if you have any concerns, questions, or objections to the material presented here. Don't forget to subscribe to the blog to read future posts!

Until next week. (:
- Caitlin

Additional Resources:

The AVMA on Raw Feeding Guidelines

Critical Review of the Literature on Raw Diet Risks and Benefits

FDA Resources on Raw Feeding Risks