True Acre vs. Ziwi Peak

Canola meal is a high protein by-product of canola oil production. This ingredient is marked controversial because it may be derived from genetically modified rapeseed, which is associated with multiple adverse health affects.

Wheat middlings are defined by AAFCO as "­coarse wheat bran, fine particles of wheat bran, wheat shorts, wheat germ, wheat flour and the offal from the tail of the mill."

Wheat middlings are marked controversial because many experts and pet owners believe wheat middlings are low quality by-products which do not provide any notable nutritional benefits.

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.

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

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).

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).

Lamb plasma is the colorless fluid part of a lamb'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 lamb plasma is considered a controversial ingredient.

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."

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.

Animal fat is a by-product of tissue rendering. The source animal is not specific and therefore we cannot be certain that the source does not include diseased animals or even euthanized dogs and cats. What's more, this ingredient is preserved with BHA/BHT, both artificial preservatives and possible carcinogens according to the World Health Organization.