In Part 1 of Dangers of Dry Food, I told you about some of the main ingredients in dry food — the “meals.” They might be a named meat meal like chicken or turkey, a by-product meal or the hodge-podge of ingredients in meat and bone meal, each one less desirable than the one before.
In addition to the meat meals, there are various grain and soybean meals used in making dry food. Generally speaking, the lower the price of the finished product the more likely it is that it is high in grain products and lower quality meat meals. Although price is not a guarantee, you can see that a manufacturer could not afford to sell a product for a low price and make it with a high-quality, more expensive protein.
The most common process for making dry cat and dog food is through extrusion. The machines used for this were adapted from machines originally used to make puffed breakfast cereal.
The manufacturers “recipe,” which usually contains a mixture of meat and grain meals as well as antioxidants (preservatives), is made into a wet dough. It is pre-heated then goes into the extruder where it is cooked at extreme heat and pressure. At the open end of the extruder, the dough passes through a shaping die and is cut off by a knife into small pieces. These pieces rapidly expand into kibble once they are exposed to normal air pressure.
Kibble is then dried in an oven until its moisture content is low enough to make it shelf stable. Once dry and cool, the kibble goes into a drum where it is sprayed with fats and a “flavor enhancer,” without which, your pet would probably not touch the kibble. This enhancer is “animal digest,” another rendered product. Due to these additives, kibble only has a shelf life of 10-12 months, even less if the manufacturer used natural preservatives like vitamin E and C. These enhancers can easily become contaminated with salmonella as many recalls and human illnesses have proven.
To make pet food nutritious, manufacturers must “fortify” it with vitamins and minerals because the quality of the ingredients they are using are often extremely variable and the harsh manufacturing processes destroy many of the nutrients the food had in the first place.
Proteins are especially vulnerable to heat, and become damaged, or “denatured,” when cooked. Because dry foods ingredients are cooked twice — first during rendering and again in the extruder — problems are much more common than with canned or homemade foods. Altered proteins may contribute to food intolerances, food allergies, and inflammatory bowel disease.¹
Enzymes are special proteins that aid in thousands of chemical reactions in the body. They are especially fragile to heat and are destroyed at even relatively low temperatures. The normal food enzymes that would help digest the food are destroyed by the heat processing that dry food undergoes. This forces the pancreas to make up for those lost enzymes. Over time, the pancreas can become stressed and enlarged, and even get pushed into life-threatening pancreatitis.²
What You Can Do
- Read your labels carefully
- If you must feed dry, be sure to use it before the expiration date
- Practice safe food handling
- Try feeding canned, homemade or raw
- ¹Get the Facts: What’s Really in Pet Food
- ²10 Reasons Why Dry Food Is Bad for Cats & Dogs
- How Products are Made: Pet Food
- How Dry Pet Food is Made
- How Are Dry Pet Foods Made?
- Excuse me, Myth?