Nutritional Information

Prescription Pet Food – Food as medicine or feed grade scam?
Dr. Karen Becker, Holistic DVM

If you're a pet parent, you've probably noticed not only the mind-boggling array of
dry and canned dog foods on the market, but also the trend toward "specialized"
diets marketed for small dogs, large breed dogs, older dogs, dogs of certain breeds and so on.

We're also seeing more and more "prescription" diets advertised for dogs with a
wide range of health conditions such as kidney or liver disease, joint disease,
obesity, food intolerances, gastrointestinal (GI) disorders, cognitive dysfunction,
urinary crystals and stones, diabetes, heart disease, cancer, dental disease and
recovery from an accident, surgery or illness.

The mainstream pet food industry as well as many in the conventional veterinary
community are working hard to convince pet parents that processed so-
called therapeutic or prescription diets are "food as medicine" and the wave of
the future.

I think fresh food diets made with human-grade human ingredients designed for
dogs with specific health conditions are a great idea (more about this shortly).
Unfortunately, what you get with a processed prescription diet is simply a modified version of the same feed-grade ingredients found in nonprescription pet food. In my experience and that of other integrative veterinarians, highly processed diets made with feed-grade ingredients (and the toxins that come along with feed-grade ingredients) are the root cause of many of the diseases pets acquire today. It's reprehensible that when dogs become sick with degenerative diseases after years of eating processed, biologically inappropriate food, their owners are told to buy a more expensive version of a similar food and consider it "medicine".

Conceptually, feeding recipes that have low oxalates, modulate urine pH, have
reduced copper or iodine, or address a specific nutritional goal is wonderful advice. The problem is, there's not a single brand of dry or canned food that uses human-grade ingredients. Because the FDA allows "animals that have died otherwise than slaughter" in pet food, and no heavy metal or contaminant testing is required for therapeutic foods purchased only through veterinarians, the quality of the raw materials going into "prescription diets" is questionable, at best.

Why processed "prescription" diets aren't good medicine:
The information in the chart below is an example of what I'm talking about. It's a
comparison of the first 10 ingredients in a regular Hill's diet and a Prescription diet.

The no-prescription diet on the left claims to improve skin and coat in 30 days. The prescription diet on the right is marketed as for dogs with skin and food
sensitivities.

Note the inferior-quality, biologically inappropriate ingredients in both these dog foods, such as multiple potato products, grains, corn, and questionable fats and oils. The diet on the right, the so-called "food as medicine" diet, is what the pet food industry and many veterinarians would have you feed a dog dealing with skin problems and food sensitivities, both of which are often the result of eating a diet like the one on the left.

It's foolish to think we can feed pets biologically inappropriate convenience food every day for years and then when health problems arise, treat them with a different version of a similar poor-quality diet. None of the processed prescription or therapeutic diets currently on the market are made with human-grade ingredients nor contain any ingredients that qualify them as needing a prescription; it's a marketing strategy.

Your veterinarian may not be a good pet nutrition resource

If your veterinarian recommends a therapeutic or prescription diet for your dog, I encourage you to ask him or her to help you create balanced, homemade, customized recipes using a tool like the Animal Diet Formulator. Alternatively, you might consider Darwin's Intelligent Design™ Veterinary Formulas that actually do contain beneficial nutraceuticals for specific medical conditions.

Otherwise, you'll be spending a lot of money for poor-quality pet food that won't improve your furry family member's health in the long run. Holistic and integrative veterinarians are often much more knowledgeable about the role nutrition plays in an animal's healing response than conventional practitioners who haven't studied the subject beyond what they learned in vet school (which was minimal, and typically taught by pet food industry reps).

Unfortunately, even the majority of board-certified veterinary nutritionists have also been schooled primarily about processed pet diets, and believe it or not, major pet food manufacturers frequently pay the tuition for DVMs studying to become veterinary nutritionists.

The ACVN (American College of Veterinary Nutrition) is the smallest of the veterinary colleges and there are relatively few veterinary nutritionists in the world. They work in veterinary schools, government agencies, pet drug companies, private animal hospitals, for themselves, and very frequently, for pet food companies.

So when a veterinary nutritionist recommends X, Y or Z food — or discourages feeding raw or homemade diets, which is common — keep in mind that many practicing veterinary nutritionists are obligated in some way to a pet food manufacturer. Strangely, the vast majority of these extensively trained nutritionists advocate for the consumption of only processed food for a pet's entire life. In fact, they caution that feeding anything except shelf-stable pellets may be dangerous to your pet's health.

Sadly, for most board-certified nutritionists, their association with a major pet food company creates an obvious conflict of interest when it comes to the advice they offer, which is typically to encourage pet owners to stick with big-name processed pet foods for the lifelong "health" of their four-legged family members.

Choosing the right nutrition for your dog

If you're wondering what diet would be best for your own pet and don't find your current veterinarian's suggestions helpful, I encourage you to try to find an integrative or holistic vet in your area (or via phone consultation) who is knowledgeable about animal nutrition. These vets, who've studied animal nutrition outside the conventional realm, can work with you to customize a balanced, species-appropriate diet to address the specific health needs of your animal.

The goal is to create a diet and supplement protocol based on your pet's individual and dynamically changing needs — a diet that mimics your pet's ancestral diet as closely as possible, but also stays within the nutritional and metabolic parameters that can set the stage for disease recovery or prevention. This is how food truly becomes medicine.

My standard recommendation is to feed your pet as much unprocessed, fresh food as you can afford, which can be tailored to address specific medical needs. Depending on your pet's medical condition, which will dictate which ingredients are selected for creating a nutritionally balanced recipe, this could be an all-fresh, living, raw food diet, or a gently cooked diet.

Gastroinestinal Issues in Dogs: What Works and What Doesn’t.

https://healthypets.mercola.com/sites/healthypets/archive/2020/12/09/gastrointestinal-issues-in-dogs.aspx

Dr. Karen Becker, Holistic DVM

In early 2018, researchers at Cornell University's College of Veterinary Medicine (CVM) began an ongoing study to evaluate the effectiveness of dietary changes in treating persistent gastrointestinal (GI) problems (aka chronic enteropathy) in dogs.

Most dogs with these types of chronic GI issues have a condition called lymphocytic plasmacytic enteritis, a form of inflammatory bowel disease (IBD). According to lead study investigator Kenneth Simpson, professor in the CVM's Department of Clinical Sciences, up to 80% of dogs with this disease respond well to changes to their diet.1

Unfortunately, most dogs with IBD "undergo a whole slew of best-guess treatments as owners and veterinarians try to give them relief," says Simpson. It has been my experience that too often, these best guesses involve multiple rounds of unnecessary antibiotics and/or corticosteroids, because veterinarians aren't trained to look first at what their GI patients are being fed. These drugs are often not only unhelpful, but they exacerbate the underlying disease.

Veterinarians who include dietary changes in their treatment plans typically recommend ultra-processed diets that are presumably easier to digest or that contain a different type of meat than the dog has been eating. Increasingly, they're also prescribing ultra-processed diets containing hydrolyzed proteins that have been chemically "smashed" into smaller pieces to avoid stimulating the immune system. According to Simpson:

"… no one really knows why or how these diets work or why the original diet caused clinical signs. We don't know the optimal way to manage those dogs."

In my opinion, switching from one ultra-processed food to another provides only a temporary respite from GI issues, and in most cases, those issues will resurface eventually. More about this shortly.

Dogs in the Study Are Fed One of Three Processed Diets

Dogs participating in the study are recruited from the CVM animal hospital as well as referring veterinarians. They're separated into three groups, two of which receive hydrolyzed protein diets, with the remaining control group eating a "high-quality maintenance mixed-protein diet."

All three diets contain the same balance of carbohydrates, protein and fat, and are supplied to the dogs' owners at no cost by Farmina, an Italian pet food company that is also sponsoring the study.

A separate fourth group of dogs with a disease known as protein-losing enteropathy are also part of the study. These dogs are much sicker overall and present a significant treatment challenge because many of them refuse to eat the prescribed diets. For the study, this group receives either of the two hydrolyzed diets, and the primary goal is to increase their interest in eating and help them gain weight.

Dogs who fail to respond after two weeks can be moved to another group receiving a different diet. Once a dog is responding well to a given diet, he or she stays on it for at least three months, ideally six or more to see if any changes are maintained.

Researchers: Study Results to Date Have Been Positive

According to the researchers, the results of the study so far are encouraging and even "dramatic" for many of the dogs. One example is a Briard rescue named Buddy, who was always full of energy until he suddenly began having serious digestive and elimination issues. His owner had been searching for answers for two years by the time Buddy joined the protein-losing enteropathy study group at Cornell.

Today, at 13 and despite his low protein levels, the dog is much improved. According to his owner, Buddy has nearly consistently solid stools, rarely has gas, has regained 25 pounds, and seems much more comfortable and less restless.

Gabby, a long-haired miniature Dachshund, suffered from colitis for most of her seven years. Her owner described her as "sick, limp, and listless," and was frustrated by "trying and failing with numerous prescription diets and medication."

Since beginning the study, Gabby has suffered only a couple of bouts of bloody vomit or stool — previously an almost daily occurrence — and she has more energy. "Feeding is much easier since I don't have to hide antibiotic powder in her food anymore," says her owner.

Hydrolyzed Protein versus Intact Protein Diets

Simpson and his colleagues are happy with their preliminary study results but are also somewhat surprised, apparently in part because they expected the dogs on the hydrolyzed diets to do much better than the dogs in the control group, who are fed regular maintenance diets.

"Conventional wisdom would suggest that the hydrolyzed diets would do better and dogs on the intact mixed-protein maintenance diets would fail to respond," he explains. "Yet, at three months, almost all dogs, independent of group, have had positive responses, which means the placebo group is performing equally well."

My guess is that almost any change in the dogs' diets would bring about a temporary improvement in their conditions as a result of the removal or replacement of a certain percentage of potentially problematic ingredients.

It should also be noted that according to Farmina's website, the company uses only natural preservatives and no genetically modified organisms (GMOs) in pet food formulas.2 It's very likely some of the study dogs were reacting specifically to synthetic preservatives and/or genetically modified ingredients in their pre-study diets. Simpson hypothesizes that:

"… while we are still in the dark about what's driving adverse reactions to food in dogs, the positive responses to a high-quality, intact mixed-protein-source diet suggest they are not a simple allergic response to intact protein. Perhaps non-protein ingredients or additives may be causing adverse reactions."

I agree with Simpson's supposition that today's epidemic of GI issues in dogs (and cats) isn't as simple as an allergic response to intact proteins; however, I do think factory-farmed meats present a problem for many pets.

And I definitely feel that all the "non-protein ingredients" and other additives found in ultra-processed diets are a foundational problem, along with the changes that occur to ingredients subjected to high heat processing, including the formation of Maillard Reaction Products (MRPs), including advanced glycation end products (AGEs) that create gut inflammation in animals.3

What I Believe Causes Food Sensitivities in Dogs

Before I discuss food sensitivities/allergies, it's important to be aware that for dogs with IBD, leaky gut (dysbiosis), or some other significant GI disorder, until the underlying disease is identified and healed, it's unlikely that treating food sensitivities alone by rotating diets will be successful.

Leaky gut has a myriad of causes in pets, with the most recently discovered culprit being toxic household dust. If you're still using Teflon pans, home scenting products (plug-ins and room sprays) and regular (non-organic) cleaning products, now is the time to set greener New Year's resolutions. The chemically laden dust in your home and the dust mites it attracts may be contributing to gut inflammation in your pet.4

As the tight junctions of the intestines break down, the first response is for the body to release fluid into the intestines in an attempt to flush the irritants out. Diarrhea is the result: nature's attempt to rid the body of harmful substances. One round of the most common treatment for diarrhea, the antibiotic Flagyl (metronidazole), and research demonstrates dysbiosis (microbiome imbalance) is the outcome for most pets.5

Add in monthly oral administration of flea and tick pesticides that negatively affect the microbiome and the repeated prescribing of more antibiotics without appropriate diagnostics, and it's easy to see why many pets in modernized countries end up with recurrent gut issues and "chronic enteropathies."

Chronic GI inflammation sets the stage for systemic food intolerances and potential food allergies, because the gut leaks contaminants and partially digested food particles into your pet's body, triggering a cascade of problems.

If the gut allows enough foreign particles into the body, your animal's immune system may perceive that something in her diet is attacking her body. To deal with the "threat," the immune system launches a counterattack just as it would against a real danger, for example, an infectious agent.

Certain substances in the diet are more likely to trigger the immune system than others, and unfortunately, the nutrient your carnivorous pet needs most — protein — is very often the culprit. Many integrative veterinarians have discovered protein reactions are much less severe or disappear with the protein is "clean" (not factory farmed) and unprocessed (raw).

Although no research has been published on why carnivores develop sensitivities to protein, we suspect foreign contaminants and food processing byproducts may be the reason. Growth hormones, antibiotics, chemical residues and MRPs may actually be the triggers, and not protein itself.

If we had multiple generations of pets raised exclusively on organic, clean, fresh, species-specific diets, we could conduct studies to determine if they also develop sensitivities to meat proteins. If this population of animals did not develop intolerances to the proteins in their diet, our suspicions about foreign contaminants and heat processing byproducts would be confirmed.

However, since 99.9% of pet foods are made with conventionally raised, factory-farmed meats (and only the leftover, rendered pieces and parts that fail to become human food), blended with glyphosate-contaminated fillers known to disrupt the microbiome,6 sensitivities will continue to be a problem for almost all susceptible pets.

And to compound the problem, often it isn't until the GI tract has been significantly compromised by the inflammation caused by a food intolerance that a dog begins to show symptoms of digestive disturbance.

Pets fed the same food day in and day out for a period of months or years can develop a sensitivity to not only the protein source, but also grains and vegetables.

If the food is made from inexpensive feed-grade raw materials (which describes the vast majority of pet food) and is highly processed (the vast majority of kibble has been cooked 4 times before reaching the bag), chances are the meat contains high levels of advanced glycation end products (AGEs), which in addition to antibiotics and hormones can prompt the immune system to overreact and cause massive systemic inflammation.

These dogs also often grow sensitive to other reactive ingredients in the food, typically inflammation-creating grains and other refined carbohydrates. Many grains have been genetically modified and sprayed with glyphosates, which can compromise the gut barrier and contribute to dysbiosis.

Certain breeds of dogs are more sensitive to the damaging effects of grains on the gut,7 but because pets don't need any starch to begin with, most do best with a grain free, low carb/starch diet to address and prevent gut problems.

My Approach with Dogs with Suspected Food Intolerances

The first thing I recommend for animals over the age of 12 months who I suspect are dealing with a food sensitivity is a NutriScan saliva test. If the first thing your own veterinarian recommends is antibiotics and/or a highly processed prescription diet, I suggest you order a NutriScan test instead. I also suggest finding an integrative veterinarian who will work with you to identify the root cause of your pet's condition and develop a customized healing protocol.

The NutriScan panel tests for 24 purified food extracts that recognize 56 food ingredients, and the results can often identify the specific ingredient(s) in your pet's food that are causing a problem, which makes it much easier to customize a diet to resolve the issue.

When an animal is having a reaction to something in her diet, her body needs a break from that food. After determining your dog's food sensitivities with a NutriScan test, my recommendation is to introduce a novel diet to promote healing. This means transitioning her to a different food she isn't sensitive to containing ingredients her body isn't familiar with.

Unfortunately, many dog foods claiming to contain "novel proteins," don't. In addition, pet food mislabeling is a widespread problem, so if you're planning to go with a commercially available processed novel diet, be aware it will undoubtedly contain ingredients you're trying to avoid.

The safest approach, at least for the first few months, is home-cooked meals that allow you to control virtually everything that goes into your dog's mouth. Second best is a human grade commercially available fresh food containing an uncommon protein, produced by a company you trust.

It's very important that all suspect foods be avoided for at least several months. Oftentimes animals experience a reaction to both the primary protein and carbohydrate sources in their diet. In addition to avoiding all potentially problematic foods, it's important to reduce or eliminate any "filler ingredients" (as well as synthetic nutrients) that can play a role in food sensitivities and inflammatory conditions.

I also believe pets with food intolerances do best on a very low-starch diet. Starches (aka soluble carbohydrates) are pro-inflammatory to the body and can exacerbate GI inflammation. Microbiome expert Dr. Holly Gantz has also seen beneficial changes in pets' microbiomes when excessive carbs are reduced.

Until new labeling standards are fully in effect, pet food manufacturers aren't required to list carbohydrate content on their labels, so you have to calculate it yourself. It's worth taking the time to do this before choosing a novel diet (less than 20% carb content is the goal).

Returning Dogs to a Regular Diet

A dog with food sensitivities should remain on a novel diet for a minimum of 2 months and preferably 3, to allow the body time to clear out the allergenic substances and begin the detoxification process.

During this 3-month period I also typically address dysbiosis with the appropriate probiotics, microbiome restorative therapy and nutraceuticals. If your pet has had multiple rounds of antibiotics, assessing the microbiome and beginning microbiome restorative therapy can be life-changing. This is where partnering with a functional medicine veterinarian that has experience in healing dysbiosis is important.

Because each case of food intolerance is unique, again, I recommend a custom formulated protocol created by a professional that understands your pet's unique set of circumstances. Once a patient has completed 2 to 3 months on a novel diet, other foods can be slowly reintroduced one at a time while the dog's response is closely monitored.

Some pets show dramatic improvement on the new diet, and in those cases, I often don't rush the reintroduction of food that could be problematic.

When the animal is stable and doing well, I encourage pet parents to find at least 1 and preferably 2 other protein sources their pet tolerates well so that every 3 to 6 months, they can rotate proteins and hopefully avoid further intolerances.

In addition, I believe the "cleaner" the proteins, the less chance your pet will become sensitive to them over time. Clean animal proteins are non-toxic, no chemical residues to contend with. For example, food animals raised on a natural diet (grass-fed, not factory farmed), as well as hormone-free animals, are better food sources for sensitive pets.

Why Hydrolyzed Pet Food Isn’t the Answer for Sensitive Pets

Dr. Katen Becker, Holistic DVM

https://healthypets.mercola.com/sites/healthypets/archive/2021/01/17/hydrolyzed-pet-food.aspx

According to a company (BRF Ingredients) that supplies chicken protein hydrolysate (hydrolyzed chicken) to ultraprocessed pet food manufacturers, "The consumer market has been showing increasing interest in purchasing quality products that can guarantee the health and well-being of their pets."1

This is a true statement, but what isn't mentioned is the fact that increasingly, consumers are becoming concerned that the highly refined commercial dry and canned diets they've been feeding their pets for several decades aren't ideal. The same pet food industry that produces those diets is attempting to answer consumer concerns by "reimagining" those diets, creating versions of them designed to cause fewer digestive and other problems for sensitive pets.

In other words, ultraprocessed pet food producers are looking for ways to climb out of the hole they've dug for themselves, and hydrolyzed proteins is one of those ways.

How Animal Protein Goes From Intact to Hydrolyzed

The hydrolyzation process was invented and patented nearly 25 years ago. According to a filing at FreePatentsOnline.com, preparing hydrolyzed food product (in this case chicken) for animal consumption involves the following process:2

"A food product for animal consumption is prepared from an animal by-product, preferably a complete avian carcass. A heated hydrolyzing agent is applied by spray or dip coating to the carcass exterior. After initiation of hydrolysis, the carcass is ground, enhanced by additives, then steam heated to a temperature of about 200 degrees F.

The heated by-product is provided as a slurry or as dry particulates to a twin-screw extruder.

As it is transported across several zones of the extruder, the by-product is thoroughly dispersively mixed and subjected to high pressures and temperatures, vented to release moisture, neutralized with a neutralizing agent, and blended under high temperatures and pressures sufficient to completely sterilize what has become a highly uniform and homogeneous by-product mass.

The by-product mass is extruded and cut into pellets, which then are dried to a moisture content at or below 10 percent."

In a nutshell, hydrolyzed proteins are intact proteins that have been chemically pulverized into smaller pieces to theoretically avoid stimulating the immune system of pets with "sensitive stomachs."

Why Hydrolyzed Proteins Became a Thing

Pet food manufacturers introduced hydrolyzed protein formulas to the marketplace by suggesting that intact proteins are the culprit causing the epidemic of diet-related health conditions in pets. Hydrolyzed protein formulas are marketed as hypoallergenic diets for pets with food sensitivities. Additional marketing claims for these foods are that they are palatable and easy to digest and feature high amino acid and protein content.

In my experience, pets fed unrefined high quality, human-grade protein from a variety of animal sources do not typically develop sensitivities to quality unadulterated proteins. It is when the same low-quality, ultraprocessed protein is fed day in and day out for months or years that leaky gut occurs and paves the way for an intolerance to a specific protein.

Many pet parents find an inexpensive ultraprocessed pet food their dog or cat really seems to like, and they feed it exclusively for long periods of time. Eventually, many of these pets develop sensitivities to certain ingredients, often the low-grade source of protein included in the formula.

In my opinion, the problem isn't intact animal protein. The problem is factory-farmed, poor quality, rendered animal protein that has been extruded and high heat processed. While no published research exists to explain why carnivores develop sensitivities to protein, I and many of my integrative veterinarian colleagues suspect foreign contaminants and food processing byproducts may be the reason.

The growth hormones and antibiotics fed to factory-farmed food animals, glyphosate residues, along with the chemical residues and MRPs (Maillard reaction products) that result from high heat processing may actually be the triggers for food sensitivities, not protein itself.

Research Suggests Hydrolyzed Proteins Aren't the Answer

Recently, I wrote about a current Cornell University College of Veterinary Medicine (CVM) study that is evaluating the effectiveness of dietary changes in treating persistent gastrointestinal (GI) problems (aka chronic enteropathy) in dogs.

Conventional veterinarians who include dietary changes in their treatment plans for GI patients are increasingly prescribing hydrolyzed protein formulas. But according to the lead author of the Cornell study, "… no one really knows why or how these diets work or why the original diet caused clinical signs."3

The dogs participating in the study are separated into three groups, two of which receive hydrolyzed protein diets, with the remaining control group eating a "high-quality maintenance mixed-protein diet." All three diets contain the same balance of carbohydrates, protein and fat.

According to the researchers, the results of the study so far are encouraging and even "dramatic" for many of the dogs. Simpson and his colleagues, while pleased with their preliminary study results, are also somewhat surprised because they expected the dogs on the hydrolyzed diets to do much better than the dogs fed regular maintenance diets.

Simpson's hypothesis:

I agree with Simpson's theory that today's epidemic of GI issues in dogs (and cats) isn't as simple as an allergic response to intact proteins; however, I do think factory-farmed meats may present a problem for pets, especially because antibiotic residues are passed up the food chain.

Grains present in many pet foods are commonly genetically modified and often harbor glyphosate residues that cause dysbiosis and leaky gut, not to mention mycotoxins (responsible for killing 28 dogs in December alone that were eating contaminated kibble).5 Adding fuel to the fire, pet foods made with legumes contain anti-nutrients that can create GI inflammation.

And I definitely feel that all the "non-protein ingredients" and other additives (e.g., flavor enhancers, emulsifiers and dyes) found in ultraprocessed diets are a foundational problem, along with the changes that occur to ingredients subjected to high heat processing, including the formation of Maillard reaction products (MRPs) as well as advanced glycation end products (AGEs) that create gut inflammation in animals.6

A Better Approach

The first thing I recommend for animals over the age of 12 months who I suspect are dealing with a food sensitivity is a NutriScan test. It's also very important that pet parents work with an integrative veterinarian to identify root causes and contributing triggers and develop a customized healing protocol.

After determining your pet's food sensitivities with a NutriScan test, my recommendation is to introduce a novel diet to promote healing. This means transitioning her to a different food she isn't sensitive to containing ingredients her body isn't familiar with.

Unfortunately, many pet foods claiming to contain "novel proteins," don't. In addition, pet food mislabeling is a widespread problem, so if you're planning to go with a commercially available processed novel diet, be aware it will undoubtedly contain ingredients you're trying to avoid.

The safest approach, at least for the first few months, is homecooked meals that allow you to control virtually everything that goes into your animal companion's mouth. Second best is a human grade commercially available fresh food containing an uncommon protein, produced by a company you trust.

Returning Your Pet to a Regular Diet

During this 3-month period I also typically address dysbiosis with the appropriate probiotics, microbiome restorative therapy and nutraceuticals. If your pet has had multiple rounds of antibiotics, assessing the microbiome and beginning microbiome restorative therapy can be life changing. This is where partnering with a integrative veterinarian that has experience in healing dysbiosis is important.

Once your pet has completed 2 to 3 months on a novel diet, other foods can be slowly reintroduced one at a time while his response is closely monitored. Some pets show dramatic improvement on the new diet, and in those cases, I often don't rush the reintroduction of food that could be problematic.

When your pet is stable and doing well, my recommendation is to find at least 1 and preferably 2 other protein sources he tolerates well so that every 3 to 6 months, you can rotate proteins and hopefully avoid further intolerances.

In addition, I believe the "cleaner" the proteins, the less chance your pet will become sensitive to them over time. Clean animal proteins are less reactive because there are no chemical residues to contend with. For example, food animals raised on a natural diet (grass-fed, not factory farmed), as well as hormone-free animals, are better food sources for sensitive pets.

Big Pet Food Says: Protein and Meat in Pet Diets Are Being ‘Hyped’

Dr. Karen Becker, DVM

https://healthypets.mercola.com/sites/healthypets/archive/2018/03/17/importance-of-protein-and-meat-in-pet-foods.aspx

Much to the dismay of the processed pet food industry, protein continues to be an ingredient of great significance to dog and cat parents. According to a pet food industry journal:

“The hype over protein for pets — including the related hype over meat first, fresh meat, high meat levels, ancestral diets, you name it — seems to continue and grow unabated, despite the fact that, until recently, not much research has existed to back the label claims and rampant internet proselytizing.”1

It’s true there’s very little pet food industry research into the benefits of diets high in meat/fresh meat for dogs and cats. I suspect it’s because most of the major pet food producers are happy to continue to use waste from the human food industry as the primary source of animal protein in their products. Those waste products undergo a rendering process. According to a 2004 report made to Congress titled “Animal Rendering: Economics and Policy,” sources for the raw products of the pet food rendering industry include:

“… [M]eat slaughtering and processing plants (the primary one); dead animals from farms, ranches, feedlots, marketing barns, animal shelters, and other facilities; and fats, grease, and other food waste from restaurants and stores.”2

So in case you thought the rendered ingredients in your dog's or cat's food came only from (presumably regulated) slaughterhouses or animal processing plants, now you know the truth. Susan Thixton (Truth About Pet

Food) often writes about why the FDA overlooks illegal ingredients in pet food.

Big Pet Food Says: Protein and Meat in Pet Diets Are Being ‘Hyped’

How is it that processed pet food companies consider the interest in protein content and real meat in dog and cat diets to be hype? It really makes me wonder if they understand that domesticated dogs are scavenging carnivores just like their ancestors and cousins in the wild, and housecats are obligate carnivores just like wild cats.

Dogs and cats haven’t evolved biologically in terms of their digestive tracts. In the wild they hunt the food that nature and their bodies tell them to eat, which is the fresh meat (and other body parts) of prey animals. Just because pet food producers are in the business of creating cheap and convenient processed diets built around biologically inappropriate ingredients doesn’t make discussion about the food dogs’ and cats’ bodies are designed to eat hype.

Why the Right Kind of Protein in the Right Amount Is so Important to Your Pet’s Health

Proteins are often called the "building blocks of life," essential to the survival of animals, and found in every organism on the planet. Here are some facts about protein from the Weston A. Price Foundation:3

It is essential to a healthy heart and body
Animal sources of protein, including eggs, are better nutritionally because they contain all the essential amino acids (amino acids are called the "building blocks of protein")
Too much poor-quality protein and too little protein can be damaging to the body
Protein isn't stored in the body like fat — it must be eaten daily
The one nutritive substance that stands before all others is protein

Your pet's body is literally made of protein, including his bones, muscles, arteries, veins, skin, hair and nails. The tissues of his heart, brain, liver, kidneys and lungs are made of proteins. Proteins oxygenate the blood and transport fat and cholesterol throughout your pet's body. The enzymes in proteins help to digest the food he eats, synthesize essential substances and break down waste products.

Proteins in combination with sterols produce hormones that regulate the sensitive chemical changes that take place constantly within your pet's body. And the chromosomes that will be passed on to your pet's offspring (and that were passed on to him) include proteins in their structure.

Plant Versus Animal Protein

One of the reasons processed pet food producers have an issue with real meat is that it’s much cheaper to use plant protein than animal protein in their products. That’s why they make statements like this:

"The protein in pet foods can be supplied by animal sources, plant sources or a combination of the two. Common animal-based protein sources used in pet food include chicken, lamb, fish meal, and beef; while common plant-based protein sources include corn-gluten meal and soybean meal."4

This statement suggests animal protein and plant protein are equivalent forms of nutrition for dogs and cats. This is absolutely not true. Dogs and cats need 22 amino acids to be healthy. Dogs can synthesize (make) 12 of those 22; cats can synthesize 11. The remaining amino acids must come from the food they eat.

Omnivores (e.g. humans) have the physiological ability to turn plant proteins into the missing pieces needed for a complete amino acid profile. To a very limited extent dogs can do this, but a cat's body isn't equipped for it whatsoever.

Why Cats MUST Eat Animal Meat and Organs

Cats must eat animal meat and organs to meet their nutritional needs, and plant-based proteins (grains and vegetables) simply aren't a good substitute. Felines lack the specific enzymes necessary to use plant proteins as efficiently as animal proteins. The proteins derived from animal tissue contain a complete amino acid profile. Amino acids are the building blocks of protein. Plant-based proteins don't contain all the amino acids critical for the health of an obligate carnivore.

Why Dogs SHOULD Eat Animal Meat and Organs

A major pet food company conducted a study several years ago that examined how the type of protein fed to adult and senior dogs affected body composition (muscle versus fat). The dogs were fed diets with varying amounts of protein from chicken and corn gluten meal.5

Dogs in one group were fed a diet of exclusively chicken; the rest were fed diets with decreasing amounts of chicken and increasing amounts of corn gluten meal. Compared with the dogs fed 100 percent chicken, the dogs fed the other diets had:

A decrease in lean tissue
An increase in body fat
Decreased levels of blood proteins that are universal markers of a well-nourished body

The same company did another study focused on the decline in body composition and muscle-specific proteins in aging dogs.6 Senior dogs were fed a 32 percent chicken-based diet, a 32 percent chicken and corn gluten meal diet or a 16 percent chicken-based diet.

The dogs fed the 32 percent chicken-based diet had better body composition than healthy young adult dogs, and identical muscle-specific protein levels. Neither of the other two groups of senior dogs (those fed chicken + corn gluten meal or the diet with just 16 percent chicken) had similar results. The pet food company concluded that feeding dogs diets containing primarily animal-based protein sources provides several benefits, including:

Helps to maintain muscle mass
Reverses some age-related changes in skeletal muscles in senior dogs
Enhances the long-term health and well-being of both adult and senior dogs

Interestingly, despite the company's conclusion years ago that animal-based protein is the best type of protein for dogs, it doesn't appear they've incorporated their study findings into their dog food formulas. A quick glance at the ingredient lists for several of the company's senior and mature adult dog foods reveals corn meal and a variety of other plant-based ingredients at the top of the list.

Important Note: Not All Animal Protein Is Digestible

Protein quality is extremely variable, including protein sourced from animals. There are highly assimilable and digestible proteins that are easy for your pet's body to absorb and use, and there are proteins that are impossible to digest. For example, beaks, feet/hooves, hides, tails and snouts are 100 percent animal protein, but all 100 percent is indigestible.

All protein has a biologic value, which is its usable amino acid content. Eggs have the highest biologic value at 100 percent. Fish is a close second at 92 percent (though I don't recommend feeding most fish to pets on a daily basis). Feathers, as you might guess, have zero biologic value. Soy is very poor nutrition for pets and I recommend avoiding it, but it has a relatively high biologic value of 67 percent. Soy can adversely affect thyroid function, as well as be allergenic and estrogenic.

Both soy and corn (which is typically genetically modified, allergenic and heavily contaminated with glyphosates) are included in many popular commercial pet foods because they provide a cheap way for pet food manufacturers to boost the total protein content on the guaranteed analysis printed on the label. Digestion and assimilation are not measured for pet foods, so manufacturers can include other types of protein that have no biologic value for the species of animal eating it.

Pet food recall expands after 70 dogs die from mold toxin.

“There's an expanded nationwide recall of Sportmix pet food products underway, after links were found between a mold-borne toxin in the food and the deaths of 70 dogs, with 80 other dogs being sickened, the U.S. Food and Drug Administration announced Monday.”

https://phys.org/news/2021-01-pet-food-recall-dogs-die.html

FDA Provides Aflatoxin Education to Pet Owners: After several recent aflatoxin recalls, the FDA provides pet owners with some significant education regarding aflatoxin poisoning pets.

“The new aflatoxin education from FDA is the first time the Agency acknowledges the risk of accumulation of low levels of aflatoxins pets can be exposed to in pet foods. “Pets are highly susceptible to aflatoxin poisoning because, unlike people, who eat a varied diet, pets generally eat the same food continuously over extended periods of time. If a pet’s food contains aflatoxins, the toxins could accumulate in the pet’s system as they continue to eat the same food.”

https://truthaboutpetfood.com/fda-provides-aflatoxin-education-to-pet-owners/