‘Meat’ refers to muscle meat of mammal, poultry, or fish. Muscle meat is good. It may have other parts like fat, skin, or nerve; however it comes directly from the slaughterhouse. Usually it has been processed, though not rendered. This is considered the best form of protein. Look for ‘meat.’
This is the slaughtered parts of mammals. It can be the kidneys, lungs, brain, spleen, intestines, blood, and liver. It doesn’t contain muscle meat. In poultry, by-product can refer to the head and feet. Basically parts that are not fit for human consumption. These parts can be diseased and have other contaminants. Meat by-products are not good and can come from animals that are old and diseased, euthanized pets (yes, other cats!), and zoo animals. The term ‘by-product’ should be avoided.
Like by-product, ‘meal’ is another word that can be scary. It’s the rendered product of mammal tissues. The meat meal can legally consist of the 4D: diseased, dying, decaying, and dead animals. That doesn’t mean that all meat meal does. High quality meat meal can be very beneficial as it is a concentrated form of protein.
Vegetable protein is found mostly in dry foods. Gluten meals are high protein extracts from which most of the carbs have been removed. Protein source from vegetables are used to boost the protein counts without using expensive animal source products. Corn gluten meal and wheat gluten are the most common types. Foods containing vegetable sources for proteins are considered the poorer quality foods.
Animal and poultry fat:
Rendered animal fat that is considered inedible for humans are sprayed directly onto dry foods to make them appealing. These fats also act as a binding agent that allows manufacturers to add other flavor enhancers. They add no nutritional value as its basically animal lard, kitchen grease, and other unwanted fats/oils. This is commonly known as the nasty smell of dry food when you first open the bag up.
Chemical preservatives like BHA, BHT, and ethoxyquin have been under scrutiny for awhile now. These chemicals have been known to be carcinogenic. I go into detail with these three below. Now, pet food companies are using natural preservatives like Vitamin C (ascorbate) and Vitamin E (tocopherols) and others to preserve the fats in food.
BHA: aka Butylated Hydroxyanisole. This chemical compound is used as an antioxidant preservative of fats in cat food. It prevents the food from becoming rancid and foul smelling. The controversy around BHA is the fact that it is a potential cancer causing agent. Studies in laboratory animals have shown that BHA in the diet can cause cancerous lesions on the skin.
BHT: aka Butylated Hydroxytoluene. Related to BHA. This chemical compound is also used as an antioxidant preservative in cat foods. In addition to the cancer causing effects, it has been linked to birth defects, kidney and liver damage. It is also used as an antioxidant in such products like rubber, pharmaceuticals, and embalming fluid.
Ethoxyquin: It is also an antioxidant that is used to prevent fats in cat food from becoming rancid. Ethoxyquin was initially developed to be a rubber stabilizer for tires. It is now mainly used as a pesticide and, of course, pet food preservative. It has never been tested for safety in cats. You will rarely see ethoxyquin listed in the ingredient label because of a loophole. Companies have to put ethoxyquin on the label if they directly place it in their foods. If they purchase, let’s say meat meal and it already has ethoxyquin in it, then they don’t have to put it on the label because they didn’t add it to the meat meal themselves.
Because of the increasing number of complaints about the use of chemical preservatives, some companies have switched to natural preservatives:
Ascorbate (Vitamin C)
Tocopherol (Vitamin E)
Oils of Rosemary, Clove, and other spices
These preservatives do not have a long shelf life like the chemical preservatives, but it provides a peace mind to cat owners about their pets’ safety.
Over time, exposure to preservatives like BHA can absolutely take its toll on a cat. This is because these chemicals, even in small traces, are stored in the fat. With repeated exposure, the levels of these preservatives grow larger in the cat.
Of course, there is always the risk of contaminants. It’s just the nature of the beast when pet food companies use the type of ingredients that they use. Some of these contaminants are destroyed by the processing of the food, but others are not.
Bacteria: As mentioned, slaughtered animals, diseased, injured, and already dead animals are used as ingredients for cat food. The carcass may not be contaminated when it dies on the farm, but it may be on the journey to the rendering plant. Contaminations include salmonella and E.coli, among others. Pet food manufacturers do not test their products for bacterial contamination.
Chemicals: With diseased or dead animals being processed as cat food, the drugs that were used to treat or euthanize them could still be present in the bodies as they are going through the rendering process. For example, penicillin and pentobarbital are two drugs that can survive the processing period unchanged.
Mycotoxins: It could be possible that grains such as wheat, and corn could be contaminated with toxins. These toxins come from mold or fungi. Modern farming practices, adverse weather conditions, and improper drying and storage of these crops can contribute to mold growth.
Just some other things to think about.