In this comparison article for Diamond vs Castor & Pollux, we'll highlight the key differences between these two pet food brands. To properly compare Diamond and Castor & Pollux, we'll use up-to-date nutritional and price information.
There are many factors to consider when choosing the best pet food brand for your pet. Factors such as ingredient quality, guaranteed analysis, product safety, brand history, and cost are among the most important factors to consider.
Throughout this Castor & Pollux vs Diamond comparison, we've utilized average data to make general comparisons. If you'd like to see individual product reviews, visit our Diamond Review Page or Castor & Pollux Review Page.
Guaranteed Analysis: Castor & Pollux vs. Diamond
According to AAFCO, all pet food labels must provide a guaranteed analysis of nutrient content. The analysis must provide guaranteed minimum percentages of crude protein and crude fat, and maximum percentages of crude fiber and moisture.
All percentages used in this comparison are averages reported on a dry matter basis.
Diamond Dog Food vs. Castor & Pollux Dog Food
Dry Dog Food
Diamond
Castor & Pollux
Crude Protein
27.6%
32.6%
Crude Fat
16.7%
17.1%
Crude Fiber
4.5%
4.2%
Wet/Canned Dog Food
Diamond
Castor & Pollux
Crude Protein
43.9%
39.9%
Crude Fat
25.8%
23.5%
Crude Fiber
4.5%
6.5%
Crude Protein Comparison For Dog Food
Dogs require twenty-two amino acids to sustain life. Twelve of these amino acids are synthesized naturally, the remaining ten are consumed. Protein is the nutrient which provides some or all of these ten essential amino acids.
The table shows that Diamond provides far less protein than Castor & Pollux. The difference in protein content is roughly 4.97%. In addition, Diamond wet dog foods also provide more protein than Castor & Pollux wet foods.
Crude Fat Comparison For Dog Food
Like protein, fats are an essential part of a dog's body. Fats are needed for the proper development and function of the canine body.
As you can see, Diamond and Castor & Pollux guarantee a similar amount of crude fat. For wet dog foods, Diamond typically provides a little more fat (about 2.30% more).
Castor & Pollux and Diamond both provide roughly the same amount of crude fiber. With regards to wet dog food, Castor & Pollux and Diamond also provide roughly the same amount of crude fiber.
Diamond Cat Food vs. Castor & Pollux Cat Food
Dry Cat Food
Diamond
Castor & Pollux
Crude Protein
36.7%
38.2%
Crude Fat
17.6%
15.7%
Crude Fiber
5.2%
4.0%
Wet/Canned Cat Food
Diamond
Castor & Pollux
Crude Protein
44.7%
43.3%
Crude Fat
22.0%
20.4%
Crude Fiber
6.1%
5.7%
Crude Protein Comparison For Cat Food
Cats require twenty-two amino acids to sustain life. Eleven of these amino acids are synthesized naturally, the remaining eleven are consumed. Protein is the nutrient which provides some or all of these eleven essential amino acids.
There is a relatively insignificant difference between the crude protein content of the two brands. With regards to wet cat food, Diamond and Castor & Pollux also provide roughly the same amount of crude protein.
Crude Fat Comparison For Cat Food
There are many ways in which dietary fat contributes to the overall health of our feline friends. Here is a short list of benefits provided by fats (not exhaustive):
Help transport nutrients across cell membranes
Fats produce metabolites, which help control inflammation
Maintain healthy blood pressure
Slow the growth of yeast infections
Fats improve the taste/texture of food.
Both brands provide roughly the same amount of crude fat. With regards to wet cat food, Diamond and Castor & Pollux also provide roughly the same amount of crude fat.
Diamond Pet Food Ingredients vs. Castor & Pollux Pet Food Ingredients
Diamond and Castor & Pollux both use the following controversial ingredients in many of their products:
Tomato Pomace
Tomato Pomace
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.
Powdered Cellulose
Powdered Cellulose
Powdered cellulose is produced from minuscule pieces of wood pulp and plant fibers. Other than its fiber content, powdered cellulose lacks any nutritional contribution.
Canola Oil (Preserved With Mixed Tocopherols)
Canola Oil (Preserved With Mixed Tocopherols)
Canola oil is a plant-derived oil from the seeds of canola plants. Although fat is an essential component of any diet, canola oil is controversial in pet food. Proponents claim that canola oil provides a better fat profile in comparison to other plant based oils. However, opponents claim that canola oil is typically produced with genetically modified rapeseed and that rapeseed oil has multiple adverse health affects.
Here are some of the controversial ingredients used only by Diamond.
Meat Meal
Meat Meal
Meat meal is produced by cooking meat 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.
White Rice
White Rice
White rice is produced by removing the husk, germ, and bran of rice grains. Unlike brown rice which contains the bran and germ, white rice is nutritionally empty.
Ground Corn
Ground Corn
Ground 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.
Brewers Rice
Brewers Rice
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.
Beef By-Products
Beef 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.
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.
Corn Gluten Meal
Corn Gluten Meal
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.
Chicken By-Product Meal
Chicken By-Product Meal
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.
Ground Whole Grain Corn
Ground Whole Grain Corn
Ground whole grain corn contains 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.
Poultry By-Product Meal
Poultry By-Product Meal
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).
Here are some of the controversial ingredients used only by Castor & Pollux.
Garlic
Garlic
Garlic in very small quantities can be an acceptable addition, however, garlic can also be toxic. Therefore many pet owners choose to completely avoid garlic.
Caramel
Caramel
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.
Pea Protein
Pea Protein
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.
Garlic Powder
Garlic Powder
Garlic powder in very small quantities can be an acceptable addition, however, garlic can also be toxic. Therefore many pet owners choose to completely avoid garlic.
Organic Pea Protein
Organic Pea Protein
Organic 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.
Organic Caramel Color
Organic Caramel Color
Organic 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.
Organic Garlic Powder
Organic Garlic Powder
Organic garlic powder in very small quantities can be an acceptable addition, however, garlic can also be toxic. Therefore many pet owners choose to completely avoid garlic.
Pea Protein Concentrate
Pea Protein Concentrate
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.
Canola Oil (Preserved With Mixed Tocopherols And Citric Acid)
Canola Oil (Preserved With Mixed Tocopherols And Citric Acid)
Canola oil is a plant-derived oil from the seeds of canola plants. Although fat is an essential component of any diet, canola oil is controversial in pet food. Proponents claim that canola oil provides a better fat profile in comparison to other plant based oils. However, opponents claim that canola oil is typically produced with genetically modified rapeseed and that rapeseed oil has multiple adverse health affects.
We believe that certain pet food ingredients are linked to adverse health affects; these ingredients are classified as harmful.
Here are some of the harmful ingredients used only by Diamond.
Menadione Sodium Bisulfite
Menadione Sodium Bisulfite
Menadione sodium bisulfite 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."
Here are some of the harmful ingredients used only by Castor & Pollux.
Menadione Sodium Bisulfite Complex
Menadione Sodium Bisulfite Complex
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."
Product Safety: Recall History of Diamond & Castor & Pollux?
Diamond has been recalled once.
March 10, 2013: low level of thiamine (Vitamin B1)
Castor & Pollux has been recalled once.
May 23, 2018: elevated levels of beef thyroid hormone
Price Comparison: Which Brand Is More Expensive?
Dry Dog Food
Diamond
Castor & Pollux
Per Pound
$1.58
$5.01
Per Calorie
$0.0010
$0.0030
Dry Cat Food
Diamond
Castor & Pollux
Per Pound
$2.31
$5.50
Per Calorie
$0.0014
$0.0033
Wet Dog Food
Diamond
Castor & Pollux
Per Pound
$3.26
$8.32
Per Calorie
$0.0056
$0.0182
Wet Cat Food
Diamond
Castor & Pollux
Per Pound
$4.46
$9.65
Per Calorie
$0.0087
$0.0214
The average cost-per-lb is heavily influenced by the varying amounts of moisture present in each brand's food products (wet vs. dry food, dry vs. freeze-dried food, etc). However, the average cost-per-kcal eliminates the influence of moisture. Therefore, the average cost-per-kcal is the better metric to consider.
If you'd like to calculate the average cost-per-day or cost-pet-year of feeding Diamond or Castor & Pollux, input your pet's weight into our cost analyzer widget.
Averages price data can identify whether or not there exists a significant price difference between two brands. However, the actual price that you'll pay for Diamond or Castor & Pollux will depend on your shopping habits.
Cost Analyzer Widget
Cost of Feeding Diamond
Cost Per Day:
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Cost of Feeding Castor & Pollux
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Pet owners who use our price comparison feature typically save more than 25% off retail prices for Diamond and Castor & Pollux. In addition, we currently have some great coupons for our readers.
Disclosure: PawDiet has an affiliate relationship with stores featured (or linked-to) in this article. We are compensated for referring customers. Thank you for shopping with our retail partners!
Where To Buy Diamond Pet Foods
You can purchase Diamond pet foods from the following stores:
31 Recipes In-Stock Today
35 Recipes In-Stock Today
35 Recipes In-Stock Today
Where To Buy Castor & Pollux Pet Foods
You can purchase Castor & Pollux pet food products from these retailers:
46 Recipes In-Stock Today
10 Recipes In-Stock Today
35 Recipes In-Stock Today
Type Of Pet Foods Available
Product
Diamond
Castor & Pollux
Dry Dog Food
27 Recipes
17 Recipes
Wet Dog Food
3 Recipes
28 Recipes
Dog Treats
6 Treats
22 Treats
Dry Cat Food
6 Recipes
6 Recipes
Wet Cat Food
3 Recipes
18 Recipes
Cat Treats
None
1 Treats
Top Rated Diamond Recipes
Dog Food
Diamond Naturals Grain-Free Wild-Caught Whitefish & Sweet Potato Formula For Dogs