Running Head: PET FOOD 1

What Goes into Commercial Pet Foods

Hailey Sorensen

Southern Utah University

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Abstract

This project aims to answer the question, “What ingredients go into commercial pet food, and

how is the industry regulated?” This research is important because pets are found in many

American households and they are often viewed as part of the family, and their health can be

very important to their owners. The majority of pets are fed a commercial pet food, but many pet

owners are ill-informed about what goes into the production of these foods. The commercial pet

food industry has become a profitable market, and it is regulated in the U.S. by the Food and

Drug Administration. There are some ingredients whose suitability in commercial pet foods is

debatable, such as rendered products and grains. A dog or cat’s diet can greatly affect their

chances of developing diseases like diabetes, especially high-fat and high-carbohydrate diets.

Numerous pet food recalls have occurred in recent years, with a major example being the 2007

melamine contamination that affected thousands of pets in North America. If consumers become

more informed about the pet food industry, it may lead to increased pressure for reformed

regulations that promote the production of healthier pet foods.

Keywords: pets, pet food, dogs, cats, diet, regulations, consumers, recalls, health

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Pet Food

Pets have become extremely common in the United States. It is estimated that 68% of all

households in the U.S. have a pet (Fox & Kenagy, 2015). In the past 50 years, the societal view

of pets in the U.S. has shifted, and animals like dogs and cats are now viewed by many people as

part of the family. The majority of pet owners in the U.S. feed their companion animals a

commercial pet food. Pets are usually fed only one kind of pet food, which means they may be

susceptible to harm if that brand of food has any kind of contamination. Pet food recalls have

been quite common in recent years, and pet food safety has become an increasingly important

concern for many people.

Despite the increase in pet food safety concern, many consumers are still uninformed

about the pet food industry and recalls continue to occur. Unhealthy pet foods can lead to

increased diseases in many companion animals, and for every recall that occurs, there are pet

owners who must face the premature death of an animal that they most likely considered a

member of their family. Pet owners should become more educated and informed about the

commercial pet food industry, because there are questionable practices and ingredients that could

negatively affect the health of pets. More knowledge about the industry may lead to increased

pressure for improving the quality and regulation of commercial pet food, thereby increasing the

health of many pets and preventing unnecessary sickness or death.

Physiology and Diet of Dogs and Cats

The diet of the domestic dog is mainly of a carnivorous nature. However, the dog is

considered an indifferent omnivore, which means that they have the ability to digest grains

(Souliere, 2014). How well they can digest them, however, depends on the type of grain and

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whether it has been cooked; dogs can digest starch that has already been cooked, as they have the

carbohydrate-digesting enzyme called amylase in their small intestine. In the wild, the grains that

dogs ingest usually comes from the stomach contents of other animals that they have consumed.

Cats are considered obligate carnivores (Souliere, 2014). They have a very small amount

of amylase in their digestive tracts, which means that they have a minimal ability to digest

grains. The digestive system of a cat is designed to break down a low-carbohydrate, high-protein

diet. Because cats are not accustomed to digesting carbohydrates, a diet that is high in starch can

lead to inflammation in the body. Cats are prone to developing diabetes and urological disorders,

so it is especially important that their food matches their physiological and dietary needs.

Industry, Market, and Regulations

Commercial pet foods have been produced in the United States for more than a century.

Currently, the U.S. pet food industry is regulated by the government, although not very heavily.

The market for commercial pet food has grown exponentially in recent years, and the production

of pet food in the world is now a multibillion-dollar industry.

In the United States, there are just a handful of companies that dominate a vast majority

of the pet food industry. They are very large companies that usually do a lot of business in other

areas, such as personal care and human food. These companies include Nestle (Friskies, Purina,

Beneful, Fancy Feast, Alpo), Mars (Royal Canin, Whiskas, Cesar, Iams), Colgate-Palmolive

(Hills Science Diet), and the J.M. Smucker Company (Gravy Train, Kibbles ‘N Bits, Meow Mix,

Milk Bone) (Aldrich, 2006). The commercial pet food industry has become very profitable, so it

is only natural that big companies became involved.

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The market for pet food has grown exponentially, and it continues to get bigger and more

profitable each year. Despite its size, the industry is still largely self-regulated. There has not

been very much research done on the nutritional needs of companion animals. Of the small

amount of research that has been done, most of it has been endorsed by pet food companies and

ingredient suppliers, which may lessen their credibility due to possible biases. Companion

animal nutrition research has never been a very high priority, and there generally is not any

direct funding from the government for further research on the topic (Aldrich, 2006). However,

further research could be important for determining ways to improve pet food manufacturing.

The Food and Drug Administration (FDA) regulates the pet food industry in the U.S.

under the Federal Food, Drug, and Cosmetic Act (FFDCA). The FFDCA prohibits the sale of

contaminated food. The FDA has limited resources, however, and their major focus is on human

food safety. Because of this, the Association of American Feed Control Officials (AAFCO)

works with the FDA to manage pet food concerns (Fox & Kenagy, 2015). The AAFCO is a

voluntary association that facilitates the formation of regulations for commercial animal food.

Controversial Ingredients

There are numerous controversial ingredients that are added to commercial pet foods.

Some of these ingredients include grains, soy, meat by-products, sugar, and preservatives. Many

of these ingredients have been found to have low digestibility in dogs and cats, or may increase

the likelihood of issues like diabetes and allergies. There has also been some controversy

surrounding the animal species origin of meat that is in pet food.

Grains

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Grains come in many forms, such as corn, wheat, and rice. Grains contain starch and

provide a large amount of carbohydrates, which can be used in the body as energy. Dogs have

the carbohydrate-digesting enzyme amylase in their small intestines, but they can only properly

digest starch if it has been cooked beforehand. Grains as an ingredient in commercial pet foods

has become a debated topic in recent years, and nowadays there are many low-grain and grain-

free options available on the market. However, the majority of pet foods still contain grains.

Most of the previous research on grains in pet food has been about how grains affect

certain problems, such as diabetes and allergies. For example, a high-protein, grain-free diet may

have harmful effects on a dog’s kidneys. Food allergies are an increasingly common problem in

dogs, and grains are often associated with these allergies.

On the other hand, grains in dog food have also been shown to be beneficial, especially

for lower gastrointestinal health. According to Souliere, the majority of consumers are ill-

informed about the nutritional needs of their pet, and further education on the topic would allow

them to better understand what their pet needs in their diet (2014). This applies to grains

especially, since they can be beneficial or harmful, depending on the animal.

Sometimes, a grain-free diet is the best option for a dog, depending on factors such as

breed, allergies, and other health conditions. In dog foods that do contain grains, wholesome

grains like brown rice and oats should be used rather than grains like wheat and corn, which are

harder to digest. Grains of any type should be nonexistent or very limited in cat foods, however,

because cats do not digest carbohydrates very well.

Rendered Products

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The process of rendering is a relatively cheap method for turning deceased animals and

animal parts that are not fit for human consumption into products that can be used in other

industries (Martin, 1997). Around half of each livestock animal in the U.S, such as cows, pigs,

and chickens, is not appropriate for human consumption; these are the materials most often used

in the rendering industry (Aldrich, 2006). The products that result from the rendering process are

used in pet and livestock feed, as well as various other purposes not related to food.

The actual process of rendering involves applying heat to the raw materials (around

250°F), which causes the fat to melt off the materials, and it is then separated from the solids.

After being heated, the moisture is removed from the materials (Aldrich, 2006). The process of

rendering kills any harmful pathogens that may have been in the raw materials. The majority of

the fat that is melted off of the materials is then used in animal feed. The rendering industry also

processes cooking oil and grease from restaurants, which may also be added to animal feed.

There is undoubtedly a significant relationship between the pet food industry and the

rendering industry. In addition to animal fats, a large portion of other rendered products are used

in the production of commercial pet foods. Common rendered ingredients that are used include

meat and bone meal and meat by-products.

Meat and bone meal is a major protein source used in pet foods. According to the

AAFCO, meat meal is the product that results from the rendering of mammal tissue. The

AAFCO’s definition of meat by-products is clean, non-rendered, non-meat parts derived from

the slaughtering of a mammal. It can include blood, bone, stomachs, rumens, and other organs

such as the lungs, kidneys, and brain (Martin, 1997). According to their standards, meat by-

products and meals should not contain substances such as hair and hoofs, but these ingredients

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are often included because it would be nearly impossible to remove every hair and hoof from the

billions of animals that are processed every year in the U.S. alone.

Animal Derivatives and Animal Species

The term “meat and animal derivatives” is a common ingredient on pet food labels.

Terms such as “chicken” in pet foods can refer to any chicken protein derivative, and not skeletal

muscle, which is what is commonly associated with the word “meat.” An article about the animal

species found in commercial pet foods mentions a significant observation that sheds light on the

pet food industry as a whole: “There appears to be no legal requirement for a minimum level of

skeletal muscle (meat) in pet foods. Furthermore, where a specific animal species is mentioned,

such as ‘with beef’, it could constitute a minor component of total animal proteins in the product

so long as it meets the minimum content of 4%” (Maine et al., 2015, p. 2). It could come as a

surprise to many consumers that the pet food they buy with the word “beef” on the label only

contains 4% beef.

The flaws in the pet food industry that allow discrepancies such as these to happen are

major weaknesses that could have many negative effects. Within the current system, it would be

fine for a pet food with the word “beef” on its label to contain beef as only a minor ingredient,

with other unspecified meats making up the majority of the protein in the food (Maine et al.,

2015). Modifying the regulations and practices of pet food labeling could be a major

improvement for the pet food industry, as it would allow consumers to be better informed about

what they are purchasing, and it would also reduce risks for pets with allergies.

Diabetes and Diet

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There are various issues that dogs and cats can develop that may be influenced by diet,

such as diabetes. Type 2 diabetes is the most common form in cats, and type 1 diabetes is the

most common form in dogs. There are genetic and environmental factors that influence the

development of the disease, and these factors can vary.

Feline Diabetes

The incidence of diabetes diagnoses in cats is increasing, but genetic factors that may

predispose cats to developing diabetes are still mostly unknown. There are important

environmental factors that have been identified, however, especially obesity and lack of physical

activity. A significant factor is diet, which may play a substantial role in the development of the

disease. According to an article about canine and feline diabetes, “High-carbohydrate diets

increase glucose and insulin levels and may predispose cats to obesity and diabetes. Low-

carbohydrate, high-protein diets may help prevent diabetes in cats at risk such as obese cats or

lean cats with underlying low insulin sensitivity” (Rand, Fleeman, Farrow, Appleton, & Lederer,

2004, p. 2072S). A low-carbohydrate, high-protein diet can also decrease the likelihood of a cat

becoming obese, which further reduces their risk for diabetes.

Cats evolved as strict carnivores, and in the wild they naturally consume high amounts of

protein and are not well adapted to ingesting a lot of carbohydrates. However, many cat foods on

the market contain large amounts of carbohydrates. This dramatic change from a low-

carbohydrate, high-protein diet to a high-carbohydrate diet, may be partly responsible for

increasing diabetes in domestic cats (Rand et al., 2004). Because cats have almost no salivary or

pancreatic amylase, which is an enzyme that digests carbohydrates, consuming a high-

carbohydrate food can put a lot of strain on their digestive and endocrine systems.

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Canine Diabetes

Diabetes mellitus is a relatively common disease in older dogs, and its prevalence is

increasing. There appears to be a significant connection between diabetes and pancreatic damage

in dogs. In about a third of cases, canine diabetes cases are caused by severe pancreatic damage

that often comes from chronic pancreatitis. Evidence of pancreatitis is found in almost half of

diabetic dogs (Rand et al., 2004). Pancreatitis in dogs is associated with high-fat diets and

possibly plays a role in the development of canine diabetes.

Natural Diets

Natural and raw diets have gained popularity in recent years. Despite the fact that the pet

food market is mostly dominated by large companies like Purina and Hill’s, there is a growing

number of natural pet food producers who focus on using more “human-grade” and natural

ingredients. Some pet foods are even organic.

According to Aldrich (2006), raw and human-edible protein sources are starting to

compete with “traditional” protein sources that the rendering industry uses. The idea of

“ancestral diets” has also become more common. Ancestral diets are designed to align with the

type of diet that a wild dog or cat would eat; they include raw meat and organs, and are high-

protein and low-carbohydrate.

Raw pet foods, which are usually ancestral diet-based, are often frozen or freeze-dried,

and have not been cooked. They usually contain around 98% skeletal muscle, organs, and bones.

In most cases, the remaining portion consists of fruits, vegetables, vitamins, and minerals. In a

recent study, it was found that feeding dogs a raw meat-based diet was more beneficial than

feeding dogs a commercial kibble. The raw meat-based diet was found to promote more

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balanced bacteria growth and resulted in healthier gut functions (Sandri, Dal Monego, Conte,

Sgorlon, & Stefanon, 2017). Natural pet foods have recently gained a lot of popularity, but raw

diets especially have become more common. One possible reason for its increased popularity is

that raw meat may have better nutritional properties than it would after being made into an

extruded food. Extrusion, which is how dry kibble is produced, damages many heat-sensitive

ingredients in the food such as proteins and fats (Aldrich, 2006). Oftentimes, these nutrients must

be sprayed back on after the extrusion process.

Contamination and Recalls

Pet food contamination and recalls have become more common in recent years, such as the

major recall in 2007 of pet foods manufactured by a company called Menu Foods, Inc.

Nonetheless, the pet food industry is getting increasingly larger, fueled by pet owners who rely

on the convenience of commercial diets to feed to their companion animals.

Melamine Recall in 2007

In 2007, there was a major pet food recall in the U.S. In fact, it was the largest pet food

recall in the industry’s history, and it led to the death of thousands of dogs and cats in the U.S.

and Canada. The magnitude of this recall drew increased attention to the industry, and made

many pet owners wary of feeding their pets food that could possibly be toxic.

In the Spring of 2007, Menu Foods, Inc., recalled more than 90 brands of contaminated

dog and cat food, and a few other pet food manufacturers also announced their own recalls. The

adulterated pet food contained wheat gluten that had been purchased from China. It was

discovered that the Chinese suppliers purposely contaminated the ingredients with melamine in

order to make the wheat gluten appear to have a higher protein content. After scientific testing

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and autopsies were performed, researchers were able to conclude that the melamine and its by-

products interacted to form crystals in the kidney tubules of dogs and cats. These crystals, which

had a low solubility, lead to nephrotoxicity and renal (kidney) failure, and caused death in many

animals.

This recall was controversial not only because of its large impact, but also because of the

circumstances that led to the contamination. After this recall, consumers’ awareness of pet food

industry regulations increased, and as a result there was more pressure for improved standards.

Not long after the melamine recall, the FDA created more regulations that were designed to

improve the pet food industry as a whole.

Mycotoxins

Another source of contamination in commercial pet foods is fungi and mycotoxins, which

are secondary metabolites produced by the fungi that can be harmful to both humans and animals

(Kvas, Marais, Steenkamp, & Lübben, 2005). Aflatoxin is a mycotoxin that is commonly found

in corn, and is associated with cancer, toxicosis, and impairment of growth (Mmongoyo et al.,

2017). In the past ten years, more than one major pet food manufacturer has recalled food due to

high levels of aflatoxin in their products, including Iams and Diamond Pet Foods (“FDA

Report”, 2006). The presence of aflatoxins in pet food means that the grains used in the food,

most likely corn, were of poor quality or were not handled or stored properly.

Conclusion

There are many practices in the pet food industry that most consumers are unaware of. If

consumers were made more aware of what goes on in the industry, there would most likely be

much more pressure from the public to improve the standards and procedures that are currently

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used. Past recalls have drawn attention to many of the issues in the industry, but there is still a

need for improvement. Because of how large and complex the pet food industry has become,

changing the industry as a whole will be a difficult process. However, an improved industry

would lead to the production of higher quality foods that may increase the health of millions of

pets.

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