How To Read and Interpret Cat Food LabelsThe majority of this is pretty much copied verbatim from what I posted a few months ago on my Feline Nutrition Tribe. It's a guide on how to interpret pet food labels in America. The laws are shoddily enforced and pet food manufacturers have loads of leeway to fuck around, but every bit of knowledge we have is power. FIGHT THE MAN. The Basics Ingredients on the label must be listed in descending order according to weight. Sounds simple enough, but pet food manufacturers can be tricky about this. One popular method of making a food seem as if there's more meat in it is known as "ingredient splitting." In short, a dry food ingredient list may read something like "Chicken, corn gluten meal, poultry by-product meal, ground yellow corn, brewer's rice, chicken fat (preserved with mixed tocopherols)...." You think oooooh, chicken's the first ingredient, how nice. But notice that corn actually appears twice in the listing, once as corn gluten meal and once as ground yellow corn, and brewer's rice is right on its heels. By separating plant ingredients of the same species into different components and categories, manufacturers can make them appear lower on the list while still adding substantial amounts to the food. And not only that, but listing "chicken" at the very top is somewhat deceptive, too. The weight of the ingredient is taken into account before it's cooked, and since dry food has most of the water removed, and since chicken is about 70% water... at the end of it, there's really not that much "real chicken" in the food at all; poultry by-product meal is the primary animal protein source in this food, because meat meals have most of their water and fat removed before being added to the extruder, therefore allowing a more accurate gauge of how much actual animal protein is present in the food. The downside to using meat meals is that they tend to be over-processed and over-cooked. At any rate, there's a good chance that when it comes down to it, the plant ingredients outweight the animal ingredients in this particular example of dry food. Ingredient names must adhere (more or less) to standard definitions as established by the AAFCO. The AAFCO is the American Association of Feed Control Officials, and no, it's not a regulatory body, it's merely an association that comes up with standards and suggestions for regulations to be implemented by regulatory bodies (in the case of pet food, usually the state government). Manufacturers must list all the ingredients in the food on the label, BUT they only need to list what they add at their manufacturing plant. This is a pretty big loophole, since this means that if they receive a shipment of fish meal that has ethoxyquin already added to it (and ethoxyquin is the preservative of choice for many fish meal providers), they don't need to include that information on their label. How to Interpret Those Fruity-Ass Names on Labels If it says just an ingredient name with no fruity modifiers, e.g. "Tuna for cats" or "Tuna cat food", that means the ingredient must make up at least 95% of the food on a dry-matter basis (70% if including water). If an ingredient name is followed by a modifier, e.g. "Beef Platter for cats", that means the ingredient must make up at least 25% of the food. If there are two ingredients followed by a modifier, e.g. "Beef and Wheat Germ Dinner for Cats," that means the two ingredients must make up at least 25% of the food, with more beef than wheat germ since it's mentioned first, and at least 3% of the total includes the second named ingredient. If an ingredient is preceded by "With", e.g. "Cat Food With Chicken Giblets," it means the ingredient must make up at least 3% of the food. It can often easily be confused with the term "Chicken Giblet Cat Food"--but trust me, the "with" makes ALL the difference in the world. If the ingredient is coupled with "flavor," e.g. "Turkey Flavored Cat Food," it means that somewhere down the line the pet food might have brushed up against a real turkey. Maybe. Basically, it just needs to have some kind of flavoring in there that's turkey-based, enough to be "detectable." This is pretty rare for cat foods, though, and something you're much more likely to see in treats or dog foods. And of course pet food manufacturers can come up with any number of names that don't indicate the percentage of ingredients, which may give them even more leeway to fuck with things. "Mixed Grill" is an example, "Premium Feast" would be another. These names annoy me and I generally avoid them, even when they come from reputable companies like Petguard (which makes a canned cat food named Premium Feast). However, this is probably unduly paranoid. Allowable Ingredient variation Did you know that pet food labels need to be in close agreement with the listed ingredients only once every six months? That means two days out of a year, pet food companies need to comply with what's in their labels. As long as "nutrient requirements are met", there can be pretty significant variation (up to 25%) the rest of the year. Some of you may remember the flap over the addition of rice to canned Wellness cat food last year--well, they were perfectly within their bounds to do that and still advertise their food as being "grainless" precisely because of that rule. Statements of Nutritional Adequacy You guys have probably noticed statements on pet food that say something like "Animal feeding tests using AAFCO procedures substantiate that this food provides complete and balanced nutrition for feline growth and reproduction" and such. Pet foods can claim that they are formulated to meet AAFCO standards for pet nutrition through three ways: by calculation, by chemical analysis and by feeding trials. Calculation basically means somebody with a nutrient database crunches the numbers for the various ingredients and then compares it with the AAFCO nutrient profiles. Chemical analysis means that... well, it's pretty clear, right? Dudes with beakers and retorts and test tubes, dissolving shit with solvents and coming up with the numbers that way. Neither of these two methods establish any kind of reliable figure for bioavailability. The third method, feeding trials, does establish that the food is adequate for meeting nutritional needs. At least, that it doesn't kill anything dead within six months (ten weeks if it's a kitten). But here's an interesting loophole for pet food manufacturers that claim they've met AAFCO standards for lifestage nutrition through feeding trials: The company doesn't have to run feeding trials on ALL of their products to put that claim on their bag. Yeah, that's right. All the company has to do is run ONE trial on ONE of their foods, and all the other products in the same "family" of foods who show that they're "similar" to the product that passed the actual trial, can also have that claim on their bag or can. Sneaky bastards, aren't they? I found this out today when I stumbled on this here web page. So what are the feeding trials? Frankly, I think they're a joke. It's not that hard to pass a feeding trial. In fact, in Small Animal Clinical Nutrition (THE nutrition textbook used in vet schools across the nation, unfortunately it's authored by various people associated with Hill's Pet Nutrition and the bias in the advice given is often very obvious) there's a case study in which several cats came down with severe copper deficiency while eating a commercial food that had passed feeding trials for growth and reproduction. Not to mention in the late 80s, many cats suffered from many classic symptoms of taurine deficiency (retinal atrophy, cardiomyopathy) while eating various cat foods that had passed AAFCO feeding trials too. Feeding trials to prove adequacy for adult cat maintenance involve:
Feeding trials to prove adequacy for pregnant/lactating cats and kittens involve:
Unless noted otherwise, information above obtained from Small Animal Clinical Nutrition, 4th ed. How To Calculate Dry Matter Percentages in Cat Food When you look at the guaranteed analysis on cat food labels, you'll notice that dry food appears to be much higher in protein and fat than canned food. So why the hell am I harping on and on about how dry food is too low in protein and too high in carbohydrates? Other than the fact that I'm a perverse, bossy bitch, it's because it's true: once you remove the water content, the average can of canned food is much higher in protein than the average dry cat food formula. In order to make an accurate nutrient comparison for any sort of food, you need to compare the food only after all the water is extracted since water content varies so much from food to food, which in turn throws off the percentages which are typically based on weight. But be aware that dry matter calculations for cat food based on the numbers on the labels are only approximate. That's because all we're typically given are maximums/minimums (which yet again gives manufacturers lots of wiggle room). The terms "crude protein" and "crude fat" also serve as, well, crude estimates more than anything else because of the methods they use to obtain these values; if you're really curious and want to know the nitty-gritty, e-mail me. (Remove the DOOTDEEDOO before mashing the SEND button, please.) So let's compare two different types of food from the same company: Wellness.
Wellness Super5Mix Salmon dry food
contains: Not-so-tricky math bit: Subtract the water content from the food: 100 - 10 = 90 ; this is the total dry matter percentage To get dry matter protein, divide the protein percentage by the total dry matter percentage: 33 / 90 x 100 = 36.67% To get dry matter fat, divide the fat percentage by the total dry matter percentage: 19 / 90 x 100 = 21.11% Not so bad, right? Well, check this out:
Wellness Turkey and Salmon Formula canned food
contains: Not-so-tricky math bit: Subtract the water content from the food: 100 - 78 = 22% ; this is the total dry matter percentage To get dry matter protein, divide the protein percentage by the total dry matter percentage: 10 / 22 x 100 = 45.45% To get dry matter fat, divide the fat percentage by the total dry matter percentage: 6 / 22 x 100 = 27.27% In short: Canned Wellness Turkey and Salmon Formula kicks the Super5Mix Salmon kibble's ass when it comes to protein and fat content. This holds true for most dry and canned foods. Unless you're feeding a prescription dry food like Purina DM (which I wouldn't recommend anyway because it's pretty shitty food), or unless you're feeding a protein-restricted canned food, a cat eating canned food will always end up eating more protein in a day than a cat eating dry, assuming you feed the same number of calories. Some Claims From "Holistic" Pet Food Manufacturers That Don't Mean Shit "Human-Grade": This term has no legal meaning. None. It sounds like it should, especially since most of us are pretty paranoid about the use of 4D meat in pet food, but it's really nothing more than a bunch of marketing puffery. It's equivalent to saying something like "New X-TREME Flavor!" (another term I hate). The implication is that the ingredients used in this particular brand of food are fit for human consumption, of course, but really they could use 5-day-old rotten leftovers from KFC and if for some reason we found out, there's really not a whole lot we could do about it. It'd be like trying to sue Doritos for not actually being X-TREME. "Hormone-Free Chicken": This is an especially stupid claim because hormone use in chickens is illegal according to federal law. All chickens in the US are "hormone-free" chickens. Even those nasty 5-day-old rotten leftovers from KFC. "USDA Inspected Meat/Meat From USDA-Inspected Plants/USDA Inspected and Passed Meat": Some more tricky dickery going on here. Again, they're trying to make you believe that the meat they use was inspected and passed as fit for human consumption, but if you examine the words carefully, they don't actually come out and say so. USDA inspectors have to check all the meat that comes to a slaughterhouse, so even the most foul, disease-ridden animal that's euthanized and gets sent to the renderer's can still qualify as "USDA Inspected Meat." The information we're actually interested in is not the fact that the meat is "inspected", what we want to know is whether after the inspection, the meat was certified as fit for human consumption or fit for animal consumption. The meat passed inspection? That doesn't mean diddly, it could've passed as feed-grade meat. And saying that the meat came from a USDA-inspected plant doesn't mean crap, either. ALL slaughterhouses need to be inspected by the USDA. Or at least, they need to be if they want to be legal operations, but I get the feeling that illegal slaughterhouses aren't that big a black market industry here.
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