What should I feed my pet?

What is the best food to feed my pet?

As a veterinarian for non-profit organizations, I am asked this question often. This article will tell you exactly how to go about picking a quality pet food without becoming victim to pet food store employees hype or expensive boutique pet food company’s marketing, and will dispel the myths that exist about pet food. 

What I am about to share with you is the culmination of my knowledge of 35 years as a passionate animal lover and advocate who went to veterinary school and took every nutrition class available to me.

The information here also reflects on going discussions I am having with many veterinarians as we face the myths, science, marketing and consumer biases surrounding pet food. It is a frustrating topic for us to deal with, because there is so much information we want our pet owners to have, but no good way of providing it in a short appointment time.

My goal is to educate the public to ensure pets are given the care they need, and avoid entry into the shelter system with expensive and preventable diseases. I strive to make pet ownership as affordable as possible because financial problems are a big reason many animals end up with me in the shelter.

I make no profit from any pet food. The information I provide is non-biased. There is this myth that all veterinarians get a few cents every time a bag of a certain brand sells (I will not mention any brands in this article). I have never seen a single check from a pet food company.

There is also a myth that veterinarians are not well educated in pet nutrition, and we get all of our training from the big pet food companies. This is false. Not only did I take multiple animal nutrition courses before entering veterinary school in order to receive a Bachelor’s of Science degree in Animal Science from UC Davis prior to entering veterinary school. Once in veterinary school at UC Davis, I completed several classes in nutrition.

In addition, most classes that were not specifically nutrition classes, such as feline medicine, canine medicine, internal medicine, dermatology, emergency and critical care, oncology, nephrology, cardiology etc… also focused a great deal on nutrition topics. This is because nutrition is the foundation of many treatment plans for animals. 

Our nutrition instructors in veterinary school were either Diplomats of the American College of Veterinary Nutrition or Residents hoping to become a Diplomat. These are animal lovers that usually complete a 4 year college program, 4 years in veterinary school, went on to complete 1-2 years of an internship and then were accepted into a 2-3 year nutrition residency. They do this because they love animals, love nutrition and love science and want to increase the body of knowledge that exists for animal nutrition. These people are hard-core. They do research, write scientific papers, and council pet owners about nutrition on a daily bases.

If your opinion can’t be influenced by the work of passionate boarded specialists doing peer reviewed international scientific research, then really, whose opinion do you consider more valid?

It may be true that decades ago, much of pet nutrition information given to veterinary students was taught by pet food companies. Historically, pet food companies have used their money and influence to manipulate research. Are there some corporate shills? They exist in every endeavor, but overall, knowing the many passionate specialists I do, I know they are independent minded people, passionate about animals and passionate about adding to the knowledge base in order to improve the lives and welfare of animals. 

Not only do we get extensive training in nutrition, once we graduate, we are bombarded all day long, from all directions by nutrition. Every pet owner who walks through the door, all of our friends, family, neighbors, and acquaintances want us to answer this one question “what should I feed my pet?” And they always ask us this in passing, like its something we can answer in 30 seconds.

Instead of trying to answer this question quickly, I am going to refer anyone who asks me about pet food to this very article.

Every pet has their own individual dietary needs, especially if there are underlying medical conditions: itchiness, obesity, IBD (inflammatory bowel disease), urinary problems, kidney disease,  diabetes etc… It is best to consult with the veterinarian treating your pet, and let them advise you about the best food for your pet based on their medical conditions. However, this article will provide you with a foundation to understand why your veterinarian is making the recommendations that they do. 

You might also want to refer to the AAHA (American Animal Hospital Association) Nutritional Assessment Guidelines that veterinarians use to make dietary recommendations for pets. 

#1 Most Important Rule: Beware of lists that exist on the internet that rank pet food. 

Do not trust internet pet food ranking lists that base their recommendations on the ingredient list. This is not a good way to assess whether a particular pet food is right for your pet. One well known internet list was made by a human dentist who was not formally trained in animal nutrition. He ranks dog food based on what pet food marketers found were important factors for their customers. Marketing research has shown most important thing pet owners look for when making a diet choice was what was on the ingredient list, and this is not an appropriate way to choose a diet.

A diet can have a fantastic looking ingredient list, but can still be a very inappropriate diet and result in vitamin/mineral imbalances, gastrointestinal upset and overall poor health. You need a diet that has undergone diet trials and has a long track record of being fed to thousands if not millions of pets. 

At the non-profits I have worked for, we receive discounts and donations of “premium” brand pet foods from high end pet food stores. These diets ranked very high on the internet lists of “best dog foods.” Despite the ranking, some of our shelter animals did very poorly on these diets.

The young ones were not growing appropriately, and high rates of vomiting and diarrhea. We would switch the animals who were doing poorly on it to a diet I know that was formulated by veterinary nutritionists, passed AAFCO feeding trials and has a great track record in the veterinary community and has been feed to hundreds of thousands, if not millions of pets. This diet is not ranked very high on the internet lists, but I know from my work in the veterinary medicine, how well it works for animals that are not growing well and have diarrhea because I have seen the results in my patients, and I saw the results in these shelter animals. 

Pet food companies know some customers want an ingredient list that shows real meat and “natural” ingredients. "Premium" and boutique pet food companies cater to this, and pet food sales people also play up this angle to sell the most high profit margin foods. While this simple way of choosing a pet food may seem appealing, it is not the best way to choose a diet for your pet.

Some of this focus on ingredients stems from the pet food recalls of 2007. Unscrupulous raw material providers, not the pet food manufacturers themselves, intentionally adulterated ingredients by adding melamine and cyanuric acid to raise the perceived protein levels in their vegetable proteins. At that time, members of the pet food industry, did not test for melamine and cyanic acid, and trusted their suppliers to provide the correct ingredients. Now every pet food manufacturer tests for these contaminants as well as others, so this problem is no longer an issue.

The legal definition of “natural” according to Association of American Feed Control Officials (AAFCO) is “…derived solely from plant, animal or mined sources, either in its unprocessed state or having been subject to physical processing, heat processing, rendering, purification, extraction, hydrolysis, enzymolysis or fermentation, but not having been produced by or subject to a chemically synthetic process and not containing any additives or processing aids that are chemically synthetic except in amounts as might occur unavoidably in good manufacturing practices.” All commercial diets are processed, so I would not put too much value in any diet labeled “natural.” This term alone does not make one diet any better than another.

The most "natural" diet for a dog or cat is to kill its prey, eat it whole, reproduce at a young age and die off at a young age so as not to take resources from the younger, healthier generation. I certainly do not want that kind of "natural existence" for my pets. I want my pets to lay on the couch, not reproduce, and live a long healthy life. Do not fall victim to the naturalistic or appeal to nature fallacy that permeates the pet food industry. 

How ingredient lists work

Lists of ingredients are ordered by weight. Every pet food company pads their ingredient list to make certain ingredients move up or down the list to appeal to consumer wants of a “natural” looking ingredient list. Animal protein is expensive, so to make animal protein jump up on the list they have several other ingredients, so they can say “beef is the #1 ingredient!”

Beware of Marketing Ploys

“Premium” refers to the price pet owners are willing to pay, and not necessarily the quality of the food.

Higher profit margin food are distributed to boutique pet food stores, but these diets are not necessarily better for your pet. People attach emotional value to where they shop. Companies target these consumer desires via different distribution channels for different types of pet food shoppers. There are those shoppers who get their pet food on sale at the grocery store, and those who would never dream of doing that and feel better about their purchase if it is made at a higher cost at a boutique pet store. This same phenomena is true of coffee, ice cream and clothing. 

Paying more for pet food does not mean you love your pet any more. 

Nutritional Adequacy Statement

Choose a food that says on the label it is “complete and balanced…” for a given life-stage (growth, adult maintenance, or both). Do not feed a diet that says “for supplemental or intermittent feeding.” Many treats are labeled as “for supplemental or intermittent feeding” to inform customers that it is intended to be feed as a treat and not as the complete diet.

However, there are many foods out there, such as one famous canned diet brand that looks like a regular diet but on the label it says “for supplemental or intermittent feeding.” You want to keep these foods to less than 10% of the total diet so as not to disrupt the nutrient balance of your pet’s overall diet.

Food Allergies

In dogs, the most common food allergens are beef, dairy, wheat, chicken and egg. In cats, the most common food allergens are beef, dairy and fish.

Here is a great article about why you should not rely on over the counter pet foods and blood testing to determine your pet’s food allergy. 

AAFCO: the Association of American Feed Control Officials.

Pet food companies can get at AAFCO approved nutritional adequacy statement of “complete and balanced…” by either generating a diet formula on a computer to make sure that it meets the established nutrient requirements, or they can go an extra step and then feed the diet to a group of animals in a controlled environment to ensure nutritional adequacy before being sold. Diets that have been formulated by computer are labeled as “formulated to meet the needs.”

Diets that have actually undergone testing in a controlled environment to ensure nutritional adequacy before being sold for feeding to other dogs and cats are labeled as have had undergone “feeding trials.” The feeding trials are not very demanding. Just 8 animals, 6 months and they must pass basic physical exam and blood work parameters. That being said, even though its not much, if a pet food has not even bothered to do a feeding trial, I have a hard time trusting it, I do not want my dog to be the one on the feeding trial. 

 I trust diets that have a long track record, are formulated by veterinary nutritionists and have been feed to hundreds of thousands, if not millions of pets.  


By-products can actually be good and necessary for your pet. By-products are the nutrient dense glands, organs, sinew, bone and cartilage that humans usually don’t eat. Those treats of pig ears, bully sticks (which are penises), hooves, tracheas etc… are all by-products. Just feeding your pet white muscle meat means that they are not getting the vitamins and minerals they would normally get if they ate the whole animal. 

The specific definition of “meat by-products” is “the non-rendered, clean parts, other than meat, derived from slaughtered mammals. It includes, but is not limited to, lungs, spleen, kidneys, brain, livers, blood, bone, partially de-fatted low temperature fatty tissue, and stomachs and intestines freed of their contents. It does not include hair, horns, teeth and hoofs.” 

There is also this myth that anything labeled “meat” could be road-kill, horse etc… and that just isn’t true. AAFCO has a specific definition for “meat” it must be from cattle, pigs, goats or sheep. Any other animal such as venison or poultry must be labeled as such.

Corn and Grain Free Foods

Pet food companies are capitalizing on the popularity of paleo diet, fear of GMO corn and gluten. In an effort to set their brands apart from larger pet food companies, boutique and "premium" pet food companies are advertising their products as “corn and grain free.” This leads consumers into believing there is something wrong with feeding diets that contain corn and grain.

These companies are not trying to help pets, they are trying to profit from consumer fear and ignorance on the subject.

  • True, corn and wheat are potential allergens, in a small percentage of pets as the chart above shows. However, beef is a far more common allergen and yet the public is not as horrified by feeding their pets beef as feeding corn or wheat. Some humans have a peanut allergy, but the rest of us are not running around afraid of peanuts.

Corn and grains are nutritious sources of carbohydrates. Corn is a good source of essential nutrients such as linoleic acid (LA, the essential omega-6 fatty acid). They aren’t just “cheap fillers” as some claim. However, now even legitimate pet food companies have to offer a “grain-free” or “holistic” line to appeal to the biases of the consumer, so the myth that corn and grain are bad is further perpetuated. 

Corn and wheat are less expensive pet food ingredients, but that does not make them inherently bad. They have been used successfully in dog foods for 100 years and cat food for the past 50 years. Years of digestibility and nutrient data support their use in pet food. Avoiding these ingredients does not result in any health benefits unless your pet has a documented allergy to these ingredients.

Less expensive ingredients mean the barriers to pet ownership are lowered, more people are able to afford keeping pets, and hopefully this will mean more pets adopted from shelters! The more expensive pet foods often means owners are sometimes spending double or triple what they would normally spend on food. I would argue those funds are better spent on things like pet insurance, and working less so you can enjoy more time with your pet.

While some canids may not have ingested corn in the wild, if you walk the trails around here, you will find some coyote poop with corn in it. Either they are eating it directily from the corn fields, getting it from eating squirrels and such that they eat who ate the corn. In fact, dogs did evolve to digest starch. 

Grain free diets can be problematic, because they are so dense calorically and highly digestible, it is easy to over feed and pets often become overweight on these diets.

If your pet is overweight, you can start by cutting back the diet by 20%, and re-weiging your pet every 2 weeks, aiming for 1-2% reduction in body weight per week. However, there is a risk that your pet may not be getting the vitamins, minerals and nutrients they need if you cut back the diet too much. In that case, a prescription weight loss diets may be needed to provide the vitamins and nutrients your pet needs but with fewer calories. 

Now, high corn diets may provide too much LA and not enough alpha-linolenic (ALA, the essential omega-3 fatty acid), however, the new 2017 AAFCO nutrient requirements are now including ALA. Flax seed, for example, is a good source of ALA. While many dogs do just fine with LA, some dogs do better on diets that have a more balance LA:ALA ratio. With a higher ALA, you might see decreased stool production, shinier coat and less shedding in some pets. This is not because corn is bad, it is just not optimal for that individual.

Some dogs may experience more gastric upset and diarrhea on grain-free diets. 

Dogs who experience fiber-responsive colitis and do better on a higher fiber diet. Grain free diets substitute other carbohydrates such as potato, tapioca and pea which do not have the same amount of research proving digestibility as wheat, corn, barley and rice. As a result, some dogs may have a bacterial dysbiosis caused by maldigestion and fermentation of these carbohydrate sources. 

Grain Free Diets and Heart Disease

In 2017 we began noticing a spate of dogs diagnosed with dilated cardiomyopathy, a disease of the heart that causes the muscles to enlarge and make it more difficult for the heart to pump. Usually, this is a genetic condition, but the newly diagnosed dogs did not have this condition in their heritage. They did have one thing in common though. They were all on grain free or exotic meat commercial dog foods with limited ingredients containing potatoes, peas, legumes or lentils. Families with multiple dogs all fed the same diet were being diagnosed and dying of dilated cardiomyopathy (DCM). 

The FDA posted an alert about the problem on July 12, 2018.

Signs of DCM include exercise intolerance, cough, labored breathing and collapse. 

Research is still ongoing regarding the exact cause of the cases of DCM in dogs feed these exotic, boutique grain-free foods. 

This is a fantastic article written by Dr. Lisa Freeman, a veterinary nutritionist and professor at The Cumming’s School of Veterinary Medicine at Tuft’s University. I encourage everyone considering a boutique diet to carefully consider this article. 

Is there horse meat, euthanized pets or road-kill in my pet food?

Many caring pet owners feed home prepared diets to their pets because they heard that pet food companies use horse meat, euthanized pets and road-kill in their diets. 

Most recently in February 2017, one pet food company was involved in a recall because pentobarbital, the drug used in euthanized animals was found in their food. 

There was an FDA report in 2000 that documented trace amounts of barbiturates in pet food. The public, and bloggers immediately assumed pet food companies were using euthanized animals in their pet food.

It is illegal to include dog and cat meat in dog and cat food. If any company were foolish enough to do this they would have to list canine meat or feline meat on the ingredients list. If any company chose to do so illegally they would face hefty fines. While this sort of thing may have happened 20-30 years ago, it is not likely happening today.

The FDA report shows that dogs and cats are not included in pet foods based on DNA analysis. So, it is thought that the barbiturate came from cattle or horse meat. It is illegal to use animals euthanized by barbiturates in pet food.

Using euthanized animals in pet food has a lot of disadvantages. Its not a reliable or consistent product, only a small quantity is available for use, it is a public relations nightmare, and many pet food manufacturing companies owners and employees are pet owners and would not condone this practice. Pet food companies are legally required to list their ingredients on the label and there is no evidence that they are ignoring this requirement and opting to use euthanized pets or roadkill. The Pet Food Institute, an industry lobby which represents the manufacturers of  ~98% of commercial pet foods, specifically prohibits rendered pet ingredients in their members’ products.


 Pet owners are concerned about the use of non-organic or GMO corn in their pet food. GMO corn has gene for resistance to glyphosate (the active ingredient in RoundUp) to allow farmers to spray for weeds without killing the corn. Many are worried that the RoundUp sprayed GMO corn will be harmful to people or pets. In response to this fear, organic products have risen in popularity. However, organic labeled products have not been shown to be any safer.

Many believe that organic farming does not use pesticides or herbicides. In fact, there are more than 3000 pesticides approved for use in organic farming and many are more toxic than glyphosate. Many of these chemicals are neurotoxins requiring a “danger” label. 

Chemicals approved for use in organic farming must come from a natural source. The public is under the assumption that natural products are somehow safer than man-made products, but this is not always the case. Man-made chemicals are not more dangerous than naturally derived chemicals. The natural compounds approved for use in organic farming are not actually safer and many have not been tested to pass health and environmental safety requirements. 

Organic foods also are not tested for toxic levels of pesticide residues. While the risks of eating conventional foods are known, the risks of eating organic foods with the chemicals they use, are unknown.

Copper sulfate is one of the most popular pesticides used in organic farming and it is more toxic than glyphosate. In reality, the toxicity of glyphosate is much lower than the levels of any of the "natural" herbicides approved for organic use, and far below the levels of natural pesticides produced by most plants themselves.

    One way to compare toxicity of chemicals is by the LD50, also known as the median lethal dose. The LD50 is the dose required to kill 50% of the members of a population. The LD50 for glyphosate is 5600 mg/kg and is considered “slightly toxic”, while the LD50 for copper sulfate, the common chemical used in organic farming is 300mg/kg and considered “very toxic”.

    Some choose organic believing that it is better for the environment. That has been shown not to be true either. The pesticides used in organic farming are harmful to the environment and organic farms produce less food per unit of land than conventional farming. Each acre of organic farm land only produces 50-80% what a conventional farm produces. It is not an efficient way to feed the world’s growing population, and it leads to the destruction of wildlife habits and poses a threat to endangered species. 


Veterinarians often see pets who are experiencing complications from their owners trying to keep their pets healthy by feeding a raw or homemade diet. Raw diets put pets at risk for salmonella, campylobacter, Listeria monocytogenes, Clostridium spp., enterotoxigenic Staphylococcus aureus and E. coli infections. A myth exists that pets are not susceptible to disease from these pathogenic organisms. Let me assure you that they most certainly are put at risk by these pathogens! Problems with nutritional imbalances as well as foreign body obstructions from eating raw bones can also occur.

A 2 year study by the FDA from 2012 showed that 16% of commercial raw food diets were contaminated with listeria, and more than 7% were contaminated with salmonella. 

Human family members are also put at risk when owners feed these diets. As the animal eats pathogenic bacteria are spread across the floor and feeding areas and pets shed the pathogenic bacteria in their feces. 

Due to the frequent problems veterinarians are seeing from raw food diets, The American Animal Hospital Associationthe American Veterinary Medical Association , the Public Health Agency of Canada and the Canadian Veterinary Medical Association have all adopted statements discouraging raw diets.

Consumers are under the impression that packaged raw diets available from the store are safe. In one study, 4 of 60 raw diets tested positive for salmonella, none of the raw diets tested in this study had undergone feeding trials.

Another raw meat diet for zoo animals was tested and found to be contaminated with salmonella. Many minerals present in the diet did not match the label, and copper and manganese concentrations exceeded the National Research Council’s (NRC’s) recommendations for adult cats.

In 2015, the Food and Drug Administration (FDA) sampled a commercial raw diet. These samples tested positive for salmonella. In their response letter to the FDA, this company claimed that it was acceptable that their food contained salmonella, and they did not need to do any microbial testing of their diets because of the fermentation process they used. Many months after the salmonella testing, no recall was ever issued by the company.

All reputable pet food companies test every batch of food for Salmonella and other microorganisms. Preferred companies even swab and culture the environment (equipment, floors, walls, storage bins, etc.). These pathogens are very difficult to control and it takes a great deal of investment and resources to keep it out of the final product.

One report showed 30% of fecal samples from dogs fed a raw food diet tested positive for salmonella. While some dogs may be assymptomatic while harboring a salmonella infection, common clinical signs include fever, lethargy, anorexia, dehydration, diarrhea (mucous or bloody), tenesmus (straining to defecate), weight loss, and abdominal pain. Pregnant dogs may abort, or give birth to stillborns. Some dogs become septic and endotoxic and become pale, and may go into collapse and shock. Pets shedding salmonella in their feces put human family members at risk, especially the young, old and immunocompromised. 

Campylobacter is another pathogen found in raw animal products that can lead to disease in pets as well as humans. Campylobacter can cause gastrointestinal disease and diarrhea and can survive in feces for 3 days. Higher rates of Campylobacter have been found in animals fed home cooked diets and table scraps.

Many pet owners have a distrust of commercial pet food companies because of the media reports of recalls and contamination, especially the 2007 recalls discussed earlier. Many opt to prepare home cooked diets for their pets. Unfortunately, pets have different nutritional requirements than humans and this often leads to nutritional imbalances. Top nutritional problems caused by home cooked diets include rickets, pancreatitis, and nutritional secondary hyperparathyroidism.

In cases of nutritional secondary hyperparathyroidism, the clinical signs include reluctance to move, abnormal gait, lameness, periosteal pain (i.e. pain upon palpation of bones), loose teeth, difficulty chewing food, constipation, dysphagia (difficulty eating), stranguria (abnormal urination), muscle tremors, weakness, posterior paresis, seizures and pathologic fractures of the spine. 

One of the many examples of nutritional deficiency occurred in German Shepherd puppies fed raw meat and steamed rice and resulted in limb deformities.

Another related condition is “rubber jaw syndrome”  where deficiencies in calcium and vitamin D cause facial swelling due to bone resorption in the skull. 

Pancreatitis can occur in certain dogs that are fed a diet that is too high in fat.

If you do want to feed your pet a homemade diet, be sure that you have your diet evaluated or formulated by a veterinary nutritionist. You can check out as well as the UC Davis Nutrition Service. They will properly supplement your diet so your pet does not suffer any nutritional deficiencies or excesses. 

Many feel that their pets have better dental health on a home prepared diet. This has been shown not to be true. In fact, one study showed pets were more likely to have dental disease when fed a home prepared diet than when fed a commercial diet. 

One of these boutique pet food companies actually used a dog in their before and after pictures that was diagnosed by my colleague as having demodex, pyoderma and a yeast infection. The dog looked horrible before, patchy hairloss, dull haircoat, and after the medications to treat the demodex, and skin infections the dog looked much better. This company used this dog as an example of how the diet helped, but made no mention of the previous disease and medications used to treat it! The dog would have likely looked better on any commercial diet, the boutique pet food had nothing to do with the results.

How much to feed

Pet food labels are just a guideline for how much to feed your pet and the Calorie requirements for an individual animal of the same weight can range anywhere from 500-1500 calories a day. 

The label cannot give a range that will work for every animal, but it is a place to start. 

The best thing to do is to keep track of your pet’s body condition score (BCS). Take a look at this chart  and see what your pet’s BCS is.

Bottom line

There are an estimated 300-400 new pet food companies created every year. These new pet food companies that popping up are trying to find a niche of pet owners to market to, claims of “natural” “organic” “premium” and “grain free” appeal to consumers desires of what they want to feed their families. Americans spend more than $22 billion on pet food and everyone is trying to get a piece of that market.

Some companies can make you feel like a really conscientious, caring pet owner because you are buying their food. As if your pet is going to live a long, cancer free life with a gorgeous shiny coat, pearly white teeth and minty fresh breath. 

There is no data to support the claims made by these "premium" or boutique  pet food companies. Some have been subjected to pet food recalls, some are in denial about the risks microbial pathogens place, and some sell to too small a population for too short of a period of time to see the potential negative effects of their diets. If you want to ensure that you are feeding the safest, healthiest diet, then feed a diet formulated by veterinary nutritionists that has undergone AAFCO feeding trials and has a long track record of being fed to a large population of animals. 

Understanding Pet Store Philosophies

There is a growing chain of high end pet food stores in my area that has a philosophy of not carrying foods that contain ingredients such as unspecified animal by-product, animal fat, meat & bone meal, artificial colors, artificial flavors, BHT, BHA or propyleneglycol. They also believe the less processing a food has undergone, the higher nutritional value it retains. Now, avoiding artificial colors and flavors is fine if that is what you want, nearly all pet foods nowadays avoid those, not that there is anything inherently wrong with something just because its “artificial” just like there is nothing inherently good about something just because it is “natural.”

Banning foods that contain these “suspect ingredients,” as they call them, does not ensure nutritional value or indicate the quality of the foods they have available. In fact, it removes some of the best, most time tested and researched diets on the market. These criteria do not mean you are getting the better, healthier choice in foods. 

Lets just explore the reasons they do not want each of these products in the pet food they sell, and why these might be misguided.

First, they do not want unspecified animal by-product and by-product meal in their foods. They claim that the proportion of intestines, organs, heads, feet and bones and the species of animals may vary too much from batch to batch and may cause digestive upset. Likewise, consider “animal fat” a suspect ingredient for the same reasons and claim that since it may come from slaughterhouse waste, grocery store fat trimmings that are inedible for human consumption, and recycled restaurant grease, the variability in the sourcing of ingredients may cause digestive problems.

However, animal fat is a very important ingredient in pet food. There is no evidence that different sources of fat can cause digestive problems. It is ironic that they worry so much about the digestive problems caused by variable sources, but are not at all concerned about the high rates of pathogens such as listeria and salmonella in the raw diets they sell (remember 16% of commercial raw food diets were contaminated with listeria, and more than 7% were contaminated with salmonella in the 2012 FDA study).

They also do not sell foods that contain butylhydroxyanisole (BHA) and butylhydroxytoluene (BHT) which are food preservatives. They claim this is because BHA has been shown to cause cancer and BHT may become toxic, or result in toxic combinations when mixed with other substances. The studies showing that these compounds are potentially dangerous, were performed on high quantities of these preservatives. 

There was a post going around Facebook a while ago that Milk-Bones caused cancer in pets due to BHA. This has been proven to be false. Many years of research has shown BHA to be safe in both human and animal food products. 

An improperly preserved pet food may become rancid more rapidly and lose nutritional value, leading to an overgrowth of fungus or bacteria and thus becoming more of an immediate problem than a diet that contains these preservatives. Nowadays though, very few diets contain these compounds due to consumer concerns.

If You Suspect a Bad Pet Food

If you notice your pet food has a foul odor, or is discolored, the can or pouch is swollen or leaking, or if your pet becomes ill while feeding the food you can report it to the FDA.

You can also view a list of recalled pet foods

Characteristics of a good diet

Formulated by veterinary nutritionists

Tested via AAFCO Feeding Trials

Batches and facilities tested for pathogens

Fed to a large number of pets 

Is an appropriate diet for your pet based on their current and ongoing medical conditions

Characteristics of a more expensive, but not necessarily better diet



Corn and Grain-Free


“meat” as the first ingredient

Premium human grade ingredients. 

You can often email pet food companies and ask them questions about their diets. This is a good list of questions from the World Small Animal Veterinary Association compiled to ask any pet food manufacturer.

1. Do you employ a full time qualified nutritionist (Appropriate qualifications are either a PhD in animal nutrition or board-certification by the American College of Veterinary Nutrition (ACVN) or the European College ofVeterinary Comparative Nutrition (ECVCN)). What is this nutritionist’s name and qualifications?

2. Who formulates your foods and what are his/her credentials?

3. Are your diets tested using AAFCO feeding trials or by,formulation to meet AAFCO nutrient profiles. If the latter, do they meet AAFCO nutrient profiles by formulation or by analysis of the finished product. 

4. Where are your foods produced and manufactured? 

5. What specific quality control measures do you use to assure the consistency and quality of your ingredients and the end product? 

6. Will you provide a complete nutrient analysis in metabolizable energy (kcal/gm) of a specific diet when requested? 

7. What kind of product research has been conducted? Are the results published in peer-reviewed journals? 


Some great articles and websites about pet food

Weeth Nutrition 

Dr. Andy Roark: The Biggest Myths About Vets and Nutrition