Reprinted with permission from “Let’s Talk About Cats” by Anita Kelsey:
Interview with Dr. Pete Coleshaw who has been 40 years in practice and now runs a cat-only clinic called Jaffa’s in Salisbury. He’s also a founding and active member of the Raw Feeding Veterinary Association.
What’s the biggest misconception regarding cats and diet in the 21st century?
I think it is that dried food is a good acceptable food for a cat.
What are the pros and cons for a cat on a dry, kibble-only diet?
Pros for kibble:
It can be cheap (but it can also be quite expensive)
It’s convenient, it can be left down all day, you can feed multiple cats on it, and that is as far as it goes in terms of pros.
Everything else is cons:
You are feeding a dehydrated diet to a species that has evolved to eat something that is 80% water, which isn’t good for bladder health.
Dried foods are all based on starch with all the intrinsic issues that brings, since most of the dried foods are actually ‘ultra processed’ – cheap ingredients of unknown origin and undetermined degree of processing.
They are formulated to meet minimum requirements of fat, protein, carbohydrates and minerals, which doesn’t reflect the bioavailability or biological ‘quality’ of the constituents.
Kibble-fed cats have a very different intestinal microbiome to their raw-fed counterparts with major health implications, as in humans.
What’s the commonest illness from a kibble-only diet?
Obesity is number one – especially when cats are given free access to unlimited amounts – and that tends to be the default setting encouraged by the manufacturers.
Urinary tract disease is probably number two.
Contributing to stress-induced cystitis, and chronic digestive upsets would be third.
For the full interview and more information from Dr. Coleshaw on vegan diets for cats, why vets recommend kibble diets and more, refer to pages 187-191 in “Let’s Talk About Cats” by Anita Kelsey.
Pet-food ingredients are listed in descending order of predominance by weight, not volume. One thing to bear in mind is that some companies use a practice called ‘splitting’, whereby ingredients, such as ground corn and corn gluten meal, can be split into two categories, therefore allowing the ingredient to appear further down the list. The consumer would then naturally assume the product contained a much lower carbohydrate quantity because the main protein ingredient appears first. Should the consumer add all of the ‘split’ corn ingredients together, they may find that the percentage is actually higher than the meat! Therefore, it’s always worth looking at the nutritional information and where the items have been
Let’s take a look at the common terms you will see in commercial cat food:
The word ‘meal’ means an ingredient that has been ground or reduced to particles with water and fat removed. It’s classified as a rendered product. According to the FDA’s Center for Veterinary Medicine (CVM) pet-food specialist, William Burkholder: “Meal is another ingredient that some people like to avoid. In processing meat meal or poultry by-product meal, by-products are rendered (heat processed), which removes the fat and water from the product. Meat or poultry by-product meal contains parts of animals not normally eaten by humans… Protein quality of by-products is sometimes better than that from muscle meat.”
Chicken meal is a combination of clean chicken flesh and skin (with or without attached bone) and is exclusive of feathers, heads, feet and entrails. The ground-up chicken meat is dried to a moisture level of 10%, which means that the percentage of protein is higher than that of chicken meat of the same weight, due to the moisture content of the latter. The downside to this is that ‘rendered meat’ claims to be free of any diseases or infections due to the rendering process, so ‘4D’ animals (dead, dying, diseased or disabled) can make up the components of chicken meal. Because of the ‘possible’ inclusion of 4D animals, chicken meal is not considered fit for human consumption. This is against EU pet-food regulations, which state that: All ingredients used for the manufacture of pet food have to be ‘fit for human consumption’ according to EU standards. Only animals declared healthy after ante- and post-mortem examination will qualify as ingredients for pet food.
Meat And Bone Meal:
Meat and Bone Meal (MBM) is also a product of rendering. It’s typically about 48–52% protein, 33–35% ash, 8–12% fat and 4–7% moisture. It’s used as animal feed, but because it’s considered a major cause of mad-cow disease (BSE) is no longer used to feed hoofed animals such as cattle, goats, sheep and other ruminants. It’s still widely used in the US as a low-cost meat for cats and dogs, as well as in some parts of Europe. Pedigree list it as an ingredient in their premium dog food. In UK abattoirs, the brain, spinal cord, trigeminal ganglia, intestines, eyes and tonsils from cattle are classified as SRM (specified risk materials) and must be disposed of appropriately. Astonishingly, most countries in Europe now use MBM as a fossil-fuel replacement for renewable energy generation, as a fuel in cement kilns, in land-filling and in incineration, which is why it’s disconcerting that the US still use it as pet food and describe it as nutritional.
Fish meal is a product made from fish and fish bones and takes the form of brown powder after the drying process. The usual types of fish used in fish meal are marine fish that contain a high percentage of bone and oil and therefore are not seen as fit for "direct" human consumption. Other sources of fish meal can be by-catch from fisheries (other specimens caught up in the fishing net) or fish waste and offal (by-products of trimmings during the fish processing). The amino-acid profile of fish meal is what makes this feed ingredient so attractive as a protein supplement.
Animal by-products (ABPs) are animal carcasses, parts of carcasses, or products of animal origin not intended for human consumption. They can present a risk to human and animal health if not used or disposed of safely. Animal by-products range from carcasses (from slaughterhouses, animal shelters, zoos and veterinarians) to animal by-product food waste (such as raw meat, fish and shellfish not fit for human consumption), to other animal by-products such as milk or eggs that are not fit for human consumption, manure and digestive-tract content, semen, ova and embryos (except when destined for breeding purposes) and catering waste.
ABPs fall into three categories, which are determined by the associated risks and whether particular products can be re-used. The following categories are those noted by the Department of Agriculture, Environment and Rural Affairs (DAERA), and will assist you in understanding which ones can end up in our pet food!:
Category 1 – material is the highest risk, and consists principally of material that’s considered a transmissible spongiform encephalopathies (TSE) risk, such as Specified Risk Material (those parts of an animal considered most likely to harbor a disease such as BSE, e.g. bovine spinal cord). Pet animals, zoo and circus animals and experimental animals are also classified as category 1 material. The risk from these animals may also be high, for example due to the level of veterinary drugs and residues they may contain; the fact that adequate diagnoses of the exact cause of death of exotic animals can be difficult to achieve; and that some species are known to harbor TSEs and may carry other diseases. Wild animals may be classified as category 1 material when they are suspected of carrying a disease communicable to humans or animals. Catering waste from means of international transport (i.e. which has come from outside the EU) is also category 1 due to the risk from exotic diseases.
Category 2 – material is also high-risk material and includes fallen stock, manure and digestive content. Category 2 is also the default status of any animal by-product not defined as either category 1 or category 3 material.
Category 3 - materials are low-risk materials. Category 3 material includes parts of animals that have been passed fit for human consumption in a slaughterhouse but which are not intended for consumption, either because they are not parts of animals that we normally eat (hides, hair, feathers, bones, etc.) or for commercial reasons. Category 3 material also includes former foodstuffs (waste from food factories and retail premises such as butchers and supermarkets). Catering waste, including domestic kitchen waste, is category 3 material.
Processed Animal Protein:
Processed Animal Protein (PAP) contains protein, fat and minerals from by-products in category 3, which are animals fit for human consumption at the point of slaughter.
Meat And Animal Derivatives:
Meat and Animal Derivatives is a generic term for animal proteins that avoids having to specify where the meat comes from: it can be any part of the animal. This enables some pet-food companies to use whichever meat is the cheapest, and there is no way to tell what it is. The meat is sourced from animals which have been inspected and passed as fit for human consumption and are the parts of the animal which are surplus to the requirements of the human food industry in the UK (e.g. heart, lung or muscle meat, which are traditionally less widely consumed).
Crude ash is what’s left over after the protein, fat and carbohydrate content has been completely incinerated, leaving a mineral residue. Crude ash content is normally low.
Animal digest is: material, which results from the chemical and/or enzymatic hydrolysis of clean and undecomposed animal tissue. The animal tissues used shall be exclusive of hair, horns, teeth, hooves and feathers, except in such trace amounts as might occur unavoidably in good factory practice and shall be suitable for animal feed.
Any kind of animal can be used including the now infamous “4D animals”, goats, pigs, horses, restaurant and supermarket refuse. Digest is used to “flavor” kibble so it becomes palatable to the animal. A miniscule amount of digest can be used for the manufacturers to then label the food “chicken flavor”. Digest is usually sprayed on to kibble.
Corn is the main ingredient for many cat and dog dry foods. The list of corn products that can be used is extensive but I will list a few below, from the AAFCO website and the book Food Pets Die For by Ann N. Martin.
Corn Gluten Meal: This is the dried residue from corn after the removal of the larger part of the starch and germ, and the separation of the bran in the wet-milling manufacture of cornstarch or syrup, or by enzymatic treatment of the endosperm.
Corn Flour: This is the fine-sized, hard flinty portion of ground corn, containing little or none of the bran or germ.
Many cat foods include wheat which, like corn, has several definitions. Here is an explanation from the AAFCO website:
Wheat Flour: Wheat flour mixed with wheat germ, bran, flour, and the ‘tail of the mill’. The term ‘tail of the mill’ means the floor sweepings of leftovers in the mill after everything else has been processed from the wheat.
Also known as corn gluten meal (CGM), maize gluten is a by-product of maize processing. Gluten is prepared by centrifugation, filtering and drying of the slurry received from the primary and secondary stages of corn refining. It’s high in protein and is cheap, so historically has been used for animal feed.
Sodium chloride is salt, and is used for fluid balance in pet food. The National Research Council lays down guidelines on sodium levels for cats and dogs.
Potassium chloride is a salt containing the compounds potassium and chlorine. It’s used as an added source of potassium in pet foods when other ingredients do not supply enough. It’s also used as a gelling agent in canned pet food.
Calcium carbonate is a chemical compound with the formula CaCO3. It’s medicinally used as a calcium supplement for humans and is widely used in pet food as an inexpensive source of calcium.
Yukka is a perennial shrub from the family Asparagaceae. Yucca extract is used to control the smell of animal waste. This is possible because saponins bind to ammonia to prevent the smell from passing into the air. It’s commonly found in food for cats and dogs and may also be found in cat litter.
The chicory plant is a member of the dandelion family and acts as a digestive aid.
Tomato pomace is a cheap by-product of tomato manufacturing. It’s what’s left over from the making of foods such as tomato juice, tomato sauce and tomato soup. It’s used in pet food as a dietary fiber as well as a source of A and B vitamins. It’s known to be rich in powerful antioxidants such as lycopene, and has a high level of soluble fiber, which, according to Wellness Pet Food, “helps create excellent stools, gut health and a strong immune system”.
Taurine is an extremely important component in cat food. It’s an organic acid found in animal tissue and plays a role in the development and function of the skeletal muscle, the retina and the central nervous system, and is essential for cardiovascular functioning. Taurine is also found to be important for fetal development, growth, reproduction, neuro-modulation, sight, hearing, blood platelets, immune response, antioxidation and bile acid. Most mammals manufacture taurine from other amino acids. However, cats cannot manufacture an amount sufficient for their needs and, therefore, must source enough taurine through their food. It can only be naturally found in muscle meat; however, it can be synthesized in a lab.
As defined by the AAFCO, natural feed is: a feed or ingredient derived solely from plant, animal or mined sources, either in its unprocessed state or having been subjected to physical processing, heat processing, rendering, purification extraction, hydrolysis, enzymolysis or fermentation, but not having been produced by or subject to a chemically synthetic process and not containing any additives or processing aids that are chemically synthetic except in amounts as might occur unavoidably in good manufacturing practices.
The use of the term “natural” on the label is false and misleading if any chemically synthesized ingredients are present in the product. Two common examples of this are propylene glycol and BHA, or butylated hydroxyanisole, which are chemically synthesized ingredients found in some pet foods.
These terms have no official definitions within the AAFCO and should be taken as a clever marketing tool with little value.
It only takes one veterinarian to support the claim “veterinarian formulated” or “veterinarian developed”, assuming that fact can be sufficiently documented.
Complementary Vs. Complete Cat Food:
Complementary and complete cat food are worlds apart in definition. In the UK, the term “complete” means a balanced diet with a range of nutrients, whereas complementary cat food ultimately means a “treat” to be served in moderation with a complete food substance. Gourmet foods are like treats, with a smaller range of nutrients, and should also be given in moderation.