Hill's Science Diet Cat Food Ingredients

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Hill's Science Diet manufactures roughly 57 different cat food products. Each product utilizes a unique set of ingredients to achieve a desired nutritional profile.

In this article, we'll explore Hill's Science Diet ingredients and answer many of the most common questions.

As of right now, our records indicate that Hill's Science Diet uses roughly 118 different ingredients.

First 5 Ingredients

Cat food ingredients in the United States are listed in descending order of pre-cooked weight. The first 5 ingredients typically constitute a significant portion of the recipe.

For Hill's Science Diet, these are the most common ingredients found within the first 5 cat food ingredients.

  1. water
  2. chicken
  3. corn gluten meal
  4. pork liver
  5. powdered cellulose

As you can see, the most common first ingredient in Hill's Science Diet is water. The most common 2nd ingredient is chicken, followed by corn gluten meal, pork liver, and powdered cellulose.

Artificial Food Coloring Dyes

Hill's Science Diet does not use any artificial food coloring dyes. According to our records, none of the 57 Hill's Science Diet cat foods contain artificial food dyes.

Artificial food coloring dyes are unnecessary and potentially harmful ingredients. In general, we not not recommend feeding any pet foods that contain artificial dyes.

In 2010, the CSPI raised serious concerns regarding the safety of many artificial dyes. Most of the studies referenced by the CSPI involved prolonged or excessive consumption. Since most cats consume the same foods throughout their lives, concerns raised by the CSPI are alarming to say the least.

To read more about Artificial Food Dyes, click here.

Animal By-Products

Hill's Science Diet does indeed use animal by-products. More specifically, 2 animal by-product ingredients were found during our analysis of Hill's Science Diet cat food ingredients.

According to AAFCO, by-products are defined as the non-rendered, clean parts, other than meat, derived from slaughtered mammals. In other words, animal by-products are the leftover ingredients that humans typically do not consume (lung, heart, tongue, stomach, intestine, blood, etc).

Many consumers have equated animal by-products with slaughterhouse waste. Animal by-products are still very controversial. Most premium brands have abandoned them in favor of specific named organ ingredients (duck liver, chicken heart, etc).

If you must feed a product with animal by-products, ensure that the specific animal source is specified. In other words, avoid ingredients such as meat by-products or poultry by-products.

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.</p><p>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 cats.

The following recipes contain pork by-products:

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.</p><p>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 cats.

The following recipes contain beef by-products:

Anonymous Meat Ingredients

Anonymous meats are animal-based ingredients which do not provide the source animal's name. These ingredients are controversial because they can come from almost any animal.

In addition, anonymous animal-based ingredients are very inexpensive and often the lowest quality meats that are still allowed to be used in pet food.

In general, we do not recommend feeding any products which contain anonymous meats. When in doubt, always contact the brand's customer service desk for further clarification.

Unfortunately, we've identified 2 anonymous meat ingredients used by Hill's Science Diet.

Fish meal is defined by AAFCO as "the clean, dried, ground tissue of undecomposed whole fish or fish cutting, either or both, with or without the extraction of part of the oil." Since the specific type of fish is not mentioned, we cannot discuss any specific qualities of this ingredient. In general, anonymous ingredients are low quality inclusions when compared to ingredients such as tuna meal, salmon meal, catfish meal, etc.

The following recipes contain fish meal:

Ocean fish can refer to multiple species of fish, since the particular type of fish is not specified, it's difficult to discuss this ingredient. The nutritional contribution of ocean fish depends on the species included; however, fish generally provides high quality protein and fat.

The following recipes contain ocean fish:

Cereal Grains

Certain Hill's Science Diet cat food recipes contain one or more grains. The specific ingredients are listed below.

For cats, we typically recommend choosing a grain-free recipe. Cats are obligate carnivores and therefore grains are not species appropriate.

The kibble production requires a binding agent. Grains are commonly used for this purpose in cat food. When purchasing grain-free cat food, grains are often replaced with another starchy source. This is also not ideal.

To avoid grains and other starchy additions, consider feeding wet or frozen recipes.

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.</p><p>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).

The following recipes contain whole grain wheat:

Wheat flour is produced by grinding uncooked wheat into a powder. In addition to dietary fiber, wheat flour provides various vitamins, minerals, and plant based protein.</p><p>Wheat is considered a controversial ingredient because of it's protein content. Plant based proteins degrade the overall protein quality in the product. In addition, many people believe wheat is 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.

The following recipes contain wheat flour:

Modified rice starch is a gluten free carbohydrate derived from rice. Typically, rice starch is used as a binder in kibble. The "modified" prefix indicates that the ingredient has been further processed to expose a certain property.

The following recipes contain modified rice starch:

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.

The following recipes contain corn gluten meal:

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.

The following recipes contain wheat gluten:

Brown rice is naturally rich in fiber and various minerals including manganese, phosphorus, and magnesium. Relative to other grains, brown rice is easy to digest.

The following recipes contain brown rice:

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 cat food.</p><p>Proponents of corn claim that corn is highly digestible and an excellent source of protein, energy, vitamins, minerals, and essential fatty acids.</p><p>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.</p><p>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 cats to sustain life. Therefore substituting corn for meat is an unsuitable substitution and actually degrades the overall protein quality of the product.</p><p>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 cat food should certainly warrant further questioning.

The following recipes contain whole grain corn:

Cracked pearled barley is barley with the outer husk and bran layers removed. Similar to regular barley, cracked pearled barley provides carbohydrates and dietary fiber. Cracked pearled barley is however not as nutritious as regular whole grain barley.

The following recipes contain cracked pearled barley:

Whole grain oats are an excellent carbohydrate source with considerable nutrients in addition to dietary fiber. More specifically, oats are rich in B vitamins and various minerals including manganese.

The following recipes contain whole grain oats:

Rice flour is a gluten-free carbohydrate source. As long as the bran and germ of the grain are included in the flour, rice flour can provide a notable amount of fiber and nutrition. However, because the type of rice ("brown" or "white") is not specified, we cannot make this determination.

The following recipes contain rice flour:

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 cat food.</p><p>Proponents of corn claim that corn is highly digestible and an excellent source of protein, energy, vitamins, minerals, and essential fatty acids.</p><p>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.</p><p>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 cats to sustain life. Therefore substituting corn for meat is an unsuitable substitution and actually degrades the overall protein quality of the product.</p><p>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 cat food should certainly warrant further questioning.

The following recipes contain corn flour:

Controversial Ingredients

In most cases, ingredients which are given the controversial classification can be substituted with higher-quality alternatives. You should evaluate each controversial ingredient independently to see if there is truly a valid cause for concern.

Keep in mind, certain sacrifices often must be made to produce cat foods at a reasonable price. In general, the more expensive the product, the fewer controversial ingredients you'll find.

In our analysis, we've identified 14 controversial ingredients inside Hill's Science Diet products. These controversial ingredients are listed below. Click on each ingredient for more information.

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.</p><p>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).

The following recipes contain whole grain wheat:

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.

The following recipes contain dried tomato pomace:

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

The following recipes contain pork plasma:

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

The following recipes contain powdered cellulose:

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.

The following recipes contain corn gluten meal:

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.

The following recipes contain wheat gluten:

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.

The following recipes contain pea protein:

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 cat food.</p><p>Proponents of corn claim that corn is highly digestible and an excellent source of protein, energy, vitamins, minerals, and essential fatty acids.</p><p>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.</p><p>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 cats to sustain life. Therefore substituting corn for meat is an unsuitable substitution and actually degrades the overall protein quality of the product.</p><p>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 cat food should certainly warrant further questioning.

The following recipes contain whole grain corn:

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.</p><p>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 cats.

The following recipes contain pork by-products:

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 cat food.</p><p>Proponents of corn claim that corn is highly digestible and an excellent source of protein, energy, vitamins, minerals, and essential fatty acids.</p><p>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.</p><p>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 cats to sustain life. Therefore substituting corn for meat is an unsuitable substitution and actually degrades the overall protein quality of the product.</p><p>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 cat food should certainly warrant further questioning.

The following recipes contain corn flour:

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.</p><p>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 cats.

The following recipes contain beef by-products:

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.

The following recipes contain soybean protein isolate:

Potentially Harmful Ingredients

Harmful ingredients are those which have been linked to adverse health effects. In general, we do not recommend feeding any product which contains any harmful ingredients.

There are certain situations where these ingredients may be necessary. We always recommend contacting Hill's Science Diet for further clarification regarding any harmful or controversial ingredient.

We have identified 1 harmful ingredient used in certain Hill's Science Diet recipes. To learn more, click on the ingredient's name.

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."

The following recipes contain menadione sodium bisulfite complex:

Hill's Science Diet Cat Food Ingredient Lists