Purina Puppy Chow vs. Hill's Science Diet

Liver is a controversial ingredient because the source animal is not specified. Anonymous animal ingredients are typically very low quality and may contain almost any animal, including dogs and cats!

Corn gluten meal is a by-product from the production of various corn products (corn starch, corn syrup, etc). It's very high in protein (nearly 60% protein) and therefore can significant boost the protein content of the product. Because plant based proteins such as corn gluten meal are inferior to meat based proteins (lack many essential amino acids), they are not suitable substitutes.

Whole grain corn is the entire corn kernel (the germ, bran, and endosperm). Corn is a cereal grain which provides a modest amount of vitamins, minerals, and plant based protein. It also happens to be one of the most controversial ingredients in pet food.

Proponents of corn claim that corn is highly digestible and an excellent source of protein, energy, vitamins, minerals, and essential fatty acids.

Opponents however believe that positive claims in regards to corn are either half-truths or completely false, we'll discuss a few of the opposing arguments.

In regards to digestibility, the claims of "highly digestible" are only true if corn is processed into a meal or flour and subsequently cooked. In regards to the protein contribution, we must note that corn is a plant based protein which does not contain all of the necessary amino acids required by pets to sustain life. Therefore substituting corn for meat is an unsuitable substitution and actually degrades the overall protein quality of the product.

Finally, we'll discuss the claims about vitamins and minerals in corn. Although corn does provide many vitamins and minerals, it not necessarily an exceptional ingredient in this regards. There are many other ingredients which are more complete and biologically appropriate. Therefore the usage of corn as the primary ingredient in pet food should certainly warrant further questioning.

Whole grain wheat contains the entire grain of wheat (the germ, bran, and endosperm). Wheat is the second most-produced cereal grain in the world (corn is the first). Although wheat is a controversial ingredient, it is not necessarily undesirable because it provides dietary fiber and many other nutrients. However, wheat contains a notable amount of plant based protein, which is inferior to meat based protein and therefore an undesirable substitution.

Wheat is also one of the most common ingredients to cause food allergies or intolerance. However, grains such as wheat are typically low offenders in comparison to certain protein sources (such as beef).

Soybean flour contains more than 50% protein. Therefore, soybean can significantly boost the protein content of the product. The inclusion of non-meat protein typically degrades the overall quality of protein in the recipe. This degradation is due to the inferior amino acid profile of plant based proteins.

Soybean hulls are a by-product of soybean oil and meal processing. They are typically regarded as low quality and inexpensive fillers which lack any significant nutritional value.

By-products are defined by AAFCO as the "non-rendered, clean parts, other than meat, derived from slaughtered mammals." Thus, meat by-products contain nearly all parts of the animal which are typically not consumed by humans. These parts include the liver, lung, spleen, kidney, stomach, blood, intestine, bone, etc.

This ingredient is marked controversial because the meat source is not identified. Anonymous ingredients such as meat by-products are typically very low quality additions. The most unpleasing property of this ingredient is that the animal source can contain any mammal, even dogs & cats.

Meat and bone meal is produced by cooking meat and bone using a process called rendering. The rendering process dramatically reduces the natural moisture of meat and thereby results in a highly condensed protein source.

This ingredient is marked controversial because the source animal for the meat is not specified. These type of anonymous ingredient are typically very low quality and certainly inexpensive additions. The most unpleasing property of this ingredient is that the meat source can contain any mammal, even dogs & cats.

Chicken by-product meal is produced by cooking chicken by-products using a process called rendering. By-products are defined by AAFCO as the "non-rendered, clean parts, other than meat, derived from slaughtered mammals." Thus, chicken by-products contain nearly all parts of chickens which are typically not consumed by humans. These parts include the liver, lung, spleen, kidney, stomach, blood, intestine, bone, etc.

Like other meat by-products, chicken by-products are considered controversial, mainly because they are inexpensive ingredients which consumers have equated with slaughterhouse waste. However, manufactures and many experts claim that animal by-products are unjustly criticized. Proponents state that "named" by-products, such as chicken by-products, supply many important nutrients required by pets.

Poultry by-product meal is a controversial ingredient because the source animal is not specified. Anonymous ingredients such as poultry by-product meal are typically low-quality ingredients in comparison to named protein by-product meals (e.g. chicken by-product meal, turkey by-product meal, duck by-product meal).

Caramel is a widely used natural food colorant. The concentrated form of caramel is typically listed as caramel color and has been linked to cancer in laboratory animals. Since our pets do not care about food color, caramel is an unnecessary addition with possible health risks.

Corn flour a ground cereal grain which provides a modest amount of vitamins, minerals, and plant based protein. It also happens to be one of the most controversial ingredients in pet food.

Proponents of corn claim that corn is highly digestible and an excellent source of protein, energy, vitamins, minerals, and essential fatty acids.

Opponents however believe that positive claims in regards to corn are either half-truths or completely false, we'll discuss a few of the opposing arguments.

In regards to digestibility, the claims of "highly digestible" are only true if corn is processed into a meal or flour and subsequently cooked. In regards to the protein contribution, we must note that corn is a plant based protein which does not contain all of the necessary amino acids required by pets to sustain life. Therefore substituting corn for meat is an unsuitable substitution and actually degrades the overall protein quality of the product.

Finally, we'll discuss the claims about vitamins and minerals in corn. Although corn does provide many vitamins and minerals, it not necessarily an exceptional ingredient in this regards. There are many other ingredients which are more complete and biologically appropriate. Therefore the usage of corn as the primary ingredient in pet food should certainly warrant further questioning.

Iron oxide is an FDA approved natural food coloring agent. It's commonly found in rusting metal and provides a reddish-brown color.

We believe food colorants are unnecessary ingredients in pet food. Other than potential harm, food colorants do not provide any nutritional value. These type of ingredients are used only to make the food look appealing to humans.

Pea protein is produced by removing the starchy parts of peas. Pea protein is considered controversial because it provides a substantial plant based protein boost. This boost is undesirable because plant based protein is typically lower in biological value when compared to meat based proteins.

Pork plasma is the colorless fluid part of a pig's blood. It may sound disgusting, but it's actually very nutritious for pets. Regardless of the nutritional aspects, consumers are shocked by this ingredient, which is why pork plasma is considered a controversial ingredient.

Poultry fat is a by-product of poultry tissue rendering. Poultry fat is a controversial ingredient because the specific protein is not specified. Such ingredients are typically low-quality in comparison to named poultry fats (e.g. chicken fat, turkey fat).

Animal liver is a controversial ingredient because the source animal is not specified. Anonymous animal ingredients are typically very low quality and may contain almost any animal, including dogs and cats!

Brewer's rice is the small fragments of rice kernel that are separated from the larger kernels of milled rice. The fragments do not contain the same nutrition profile of the whole kernel and therefore brewer's rice is a lower quality grain. Brewer's rice is typically regarded as an inexpensive and low quality filler.

Wheat gluten is the main protein of wheat. Although wheat gluten is mostly protein, wheat gluten is considered controversial because it significantly boosts the protein content of the product. This is undesirable because plant based protein does not provide the same amino acid profile as meat based protein.

Caramel color is a concentrated form of caramel, a natural food colorant. Caramel color has been linked to cancer in laboratory animals. Since our pets do not care about food color, caramel color is an unnecessary addition with possible health risks.

Tomato pomace is a by-product of tomato manufacturing. It's considered a controversial ingredient because many people believe it is an inexpensive low quality filler. However, tomato pomace provides a notable amount of dietary fiber, B vitamins, Lycopene, and vitamin A. Although it is a very inexpensive ingredient, it is not nutritionally empty.

By-products are defined by AAFCO as the "non-rendered, clean parts, other than meat, derived from slaughtered mammals." Thus, beef by-products contain nearly all parts of the beef which are typically not consumed by humans. These parts include the liver, lung, spleen, kidney, stomach, blood, intestine, bone, etc.

Like other meat by-products, beef by-products are considered controversial, mainly because they are inexpensive ingredients which consumers have equated with slaughterhouse waste. However, manufactures and many experts claim that animal by-products are unjustly criticized. Proponents state that "named" by-products, such as beef by-products, supply many important nutrients required by pets.

By-products are defined by AAFCO as the "non-rendered, clean parts, other than meat, derived from slaughtered mammals." Thus, pork by-products contain nearly all parts of pork which are typically not consumed by humans. These parts include the liver, lung, spleen, kidney, stomach, blood, intestine, bone, etc.

Like other meat by-products, pork by-products are considered controversial, mainly because they are inexpensive ingredients which consumers have equated with slaughterhouse waste. However, manufactures and many experts claim that animal by-products are unjustly criticized. Proponents state that "named" by-products, such as pork by-products, supply many important nutrients required by pets.

Powdered cellulose is produced from minuscule pieces of wood pulp and plant fibers. Other than its fiber content, powdered cellulose lacks any nutritional contribution.

Dried tomato pomace is a by-product of tomato manufacturing. It's considered a controversial ingredient because many people believe it is an inexpensive low quality filler. However, tomato pomace provides a notable amount of dietary fiber, B vitamins, Lycopene, and vitamin A. Although it is a very inexpensive ingredient, it is not nutritionally empty.

Pea protein concentrate is produced by removing the starchy parts of peas. Pea protein concentrate is considered controversial because it provides a substantial plant based protein boost. This boost is undesirable because plant based protein is typically lower in biological value when compared to meat based proteins.

Soy protein isolate is a highly refined/purified form of soy bean protein. Roughly 90% of soy protein isolate is protein. The inclusion of non-meat protein typically degrades the overall quality of protein in the recipe. This degradation is due to the inferior amino acid profile of plant based proteins.

Menadione sodium bisulfite complex is a synthetic version of vitamin K that has been linked to many health concerns. Research has suggested possible toxic reactions in liver cells and red blood cells among other serious problems. In fact, one large chemical supplier warns, "The substance is toxic to kidneys, lungs, liver, mucous membranes. Repeated or prolonged exposure to the substance can produce target organs damage."

Butylated hydroxyanisole (BHA) is an artificial preservative and possible cancer-causing agent. Studies have show that BHA can be linked to various tumors in laboratory animals.

Butylated hydroxytoluene (BHT) is an artificial preservative and possible cancer-causing agent. BHT is banned in several countries, but the FDA has classified BHT as "generally recognized as safe."

Red 3 is an artificial dye which the FDA has confirmed can cause cancer in laboratory animals.

Blue 2 is an artificial dye which can increase the likelihood of tumors according to the Center for Science in the Public Interest. Like other dyes, blue 2 does not provide any nutritional value.

Red 40 is the most widely used artificial dye in consumer goods. Studies have shown that red 40 may accelerate the appearance of immune-system tumors in mice, cause allergy-like reactions and trigger hyperactivity in children.

Yellow 5 is an artificial dye which may be contaminated with several cancer-causing chemicals. Like other dyes, yellow 5 does not provide any nutritional value.

Yellow 6 is an artificial food dye which may be contaminated with cancer-causing chemicals. According to the Center For Science In The Public Interest, yellow 6 can cause adrenal tumors in animals.

The ingredient "added color" is ambiguous and may include various artificial dyes. Most artificial dyes have been linked to various chronic diseases.