Pet Food

The Raw Food Diet Debate

    Occasionally clients will ask questions as to whether a raw food diet would be more beneficial to their pets. The wild ancestors of the domestic dog and cat ate raw food, so it is perceived that this must be a natural healthy diet. Unfortunately, this is not the case. The average life span of a wild wolf is 4 to 8 years. A captive wolf can live to 16 years. The average life span of a feral cat is about 2 years. A house cat can live to be 16 to 20 years. As dogs became domesticated, they were fed our leftover table scraps. Since people cook most of their food, dogs evolved on a cooked diet.    
    
Wild wolves, eating raw meat and bones, can be prone to diarrhea and vomiting caused by food-borne bacteria and viruses, and bowel perforation or impaction from bone fragments. Either the wolves slowly get better on their own, or they die. Our companion dogs have the availability of medications and/or surgery through our veterinarians, when stomach or bowel problems arise. Domestic cats continue to eat a raw diet, when available, e.g. mice and other small rodents. These rodents carry tapeworm, which consume the nutrients meant for the cat. A trip to the veterinarian for some deworming tablets usually resolves this issue. 
    There is a public health concern with raw meat diets. Even if the companion animal shows no symptoms, the feces and vomitus can be contaminated which then can be transmitted to children and immunocompromised individuals. Some of the bacteria found in raw food diets include: salmonella, campylobactor, escherichia coli (E coli), and yersinia entercolitica (bubonic plague). Intestinal parasites can also be present in raw meats: toxoplasma gondii, toxocara canis (round worm), trichnella spiralis, etc.
    Through testing it is found that 89% of commercial raw food diets are contaminated. There is no specific evidence that shows raw food diets are superior to homemade or commercial diets. In fact, there have been no feeding trials done to evaluate the nutritional adequacy of raw food diets. Most are nutritionally unbalanced.
    It is important to know why a raw food diet is chosen. Some pet owners believe that cooking food, as with a commercial diet, destroys the enzymes that are necessary for digesting food. These enzymes are digested in the animal's stomach and are non-functional. Pets secrete their own enzymes in the stomach and duodenum (small intestine) to digest their food. Owners who want to feed a homemade diet are encouraged to cook the meat and have a board-certified veterinary nutritionist advise in making the balanced diet. Cooking meat kills bacteria and parasites and makes nutrients more available by breaking down the cellulose and proteins. If owners still insist on feeding a raw meat diet, great care must be taken in thoroughly washing all cutting boards, counter tops, mixing bowels, utensils and especially hands, to avoid bacterial contamination. These owners should also be alert for signs of food borne illness e.g. vomiting and diarrhea. "Nutrients" determine a balanced diet, not "Ingredients".

References:
Yin, Sophia, DVM, MS, Raw Food Diets, Veterinary Forum, November 2007.
Tefend, Mary, RVT, MS, Top 10 Nutrition Myths, Veterinary Technician Magazine, December 2007.

Reading the Pet Food Label:  "Comparing Apples to Oranges"
 
    At some point you have probably stood in the pet food aisle of the local store and asked yourself which food should I choose? What food would be best for my pet? There are numerous brand names and within those brand names, there are those labeled lifestyle (ie.  puppy, active, senior), light, natural etc. Understanding pet food labels and the ingredients in them requires mathematics, patience, and determination. It is a complex topic. 
    Most manufactured pet foods follow the standards set by the Association of American Food Control Officials or AAFCO in the United States. Canada also recognizes these standards. Examine the package to find the declaration regarding AAFCO standards. The statement may say that this product is formulated to meet the nutritional levels established by AAFCO. This means that the formulation was tested in a laboratory and meets AAFCO standards. However, no feeding trials were performed so palatability and taste were not tested. Or, the statement may say, animal feeding tests using AAFCO procedures substantiate that this product provides complete and balanced nutrient for... It is more expensive for the manufacturer to put the product through feeding trials but it is the best way to determine nutritional adequacy.
    AAFCO sets minimum or maximum standards for the various elements in the food. These elements are listed on the package under the title Guaranteed Analysis. Lets take protein for example. In the Medical Preventative Diet for dogs, the label reads, Crude Protein ...min 31.5%. This means that for this formulation the product can contain no less than 31.5% crude protein. The product may contain 33% crude protein but cannot contain 29%. And so it is with all the other nutrients in the guaranteed analysis. 
    One would think that if the guaranteed analysis is listed on the package,  you should be able to compare one pet food against another. If only it could be that easy. The guaranteed analysis is presented as the nutrient value per 100g of food as fed. That means, as the food is fed from the package or can. However, the moisture content of each food may vary; kibble varying between 8-12% moisture and canned food between 75-80% moisture depending upon the brand. This is like comparing apples to oranges.
    To compare apples to apples, we have to take the moisture component out of the equation so that we are comparing only the dry matter components. This comparison is known as comparison on a dry matter basis. 

Here are three different products.

Nature's Best Feline                    Hill's K/d Diet Feline                    Friskies - Mariner's Catch Feline (canned)
Crude Protein minimum 29%      Crude Protein minimum 24%      Crude Protein minimum 11%
Crude Fat minimum 17%            Crude Fat minimum 19%            Crude Fat minimum 3%
Crude Fibre maximum 2%          Crude Fibre maximum 3%          Crude Fibre maximum 1%
Moisture maximum 8%               Moisture maximum 10%              Moisture maximum 78%
 
    The Nature's Best product has a moisture content of 8% in 100g. So the dry matter would constitute 92% or 92 g (100% - 8% = 92%/100). Crude Protein for Natures Best is 29% on an as fed basis. To determine the protein content on a dry matter basis, take 29 and divide it by 92, then multiply by 100 to get the protein content. (29/92 = .315 X 100 = 31.5%) Crude protein on a dry matter basis is 31.5%.
    Now lets look at the Hill's K/d.* Dry matter = 100 - Moisture (10) or 90% or 90 g, Crude Protein = 24/90 = .266 x 100 = 26.6%.
    And Friskies - Mariner's Catch, Dry matter = 100 - Moisture (78) or 22% or 22 g, Crude Protein = 11/22 = .500 x 100 = 50%.
 
    Here we can see that the canned food is much higher in protein on a dry matter basis than as indicated on the label on an "as fed basis". We can compare the other elements on the label in a like manner:

Crude Fat:      Nature's Best - 17/92 = .184 x 100 = 18.4%
                       Hill's K/d - 19/90 = .211 x 100 = 21.1%
                       Mariner's Choice - 3/22 = .136 x 100 = 13.6%
Crude Fibre:   Nature's Best - 2/92 = .021 x 100 = 2.1%
                       Hill's K/d - 3/90 =.333 x 100 = 3.3%
                       Mariner's Choice - 1/22 = .045 x 100 = 4.5%

    Hill's K/d is a therapeutic diet for cats suffering from renal insufficiency. Protein is processed by the kidneys so lowering the protein content of the food means the kidneys do not have to work as hard. AAFCO requires that the manufacturer report the minimum percent of crude protein on the product label. Hill's also reports the maximum percent of crude protein on the label because the protein level for cats on this diet is critical. (Crude Protein = maximum 29% as fed, Crude Protein = 29/90 = .322 x 100 = 32.2%). 
    In this case, the veterinarian and the owner can be assured that the maximum percent of Crude Protein will not exceed 32.2%. You must remember the minimum or maximum standard is just that. Minimum means that the product must contain at least that "%" but may contain more. Likewise with the maximum standard, the product must not exceed the maximum percent but the product may contain less.
    How is all this math helpful? This process of converting the nutrient element levels to a dry matter basis allows us to compare one food on the store shelf to another. It is the first step in understanding a pet food label. We also need to understand what the terms in the ingredient list mean and what the descriptive terms on the label mean (ie, light, natural etc.).
 
References:
Smith, C. Pet Food Math, Dogs in Canada, November, 2009.
Tefend, M. Top 10 Nutrition Myths, Veterinary Technician, December, 2007.
Watson, H. Energy, How to Evaluate Diets forTtheir Nutrient Content, Dogs in Canada, January 2005
.

Reading Pet Food Labels:  "What Is In The Name"

    Many clients ask about the foods they are feeding their pet. The above article discusses how difficult it is to compare one food with another by reading the pet food label, especially when comparing foods of different moisture content. This article is a continuation of that article. Conscientious consumers wanting the best and healthiest products for themselves and their pets read product labels. This can be very difficult when one does not understand what the label is telling you. 
    The advertising industry uses marketing ploys and key words to attract the consumer’s attention. If uninformed, the consumer can be led to misinterpret these words. The pet food industry is no different. Every word on the pet food label is there to sell the product. Certain label claims are regulated by the Association of American Food Control Officials or AAFCO. It is important that the consumer understand the meaning behind these words.
    For example, if the label contains the word “meat”, AAFCO designates that particular product must contain 95% meat not including water added and meat should be listed first on the ingredient list. An example would be “Beef for Dogs”. On the other hand, there is no definition or guideline from AAFCO for the word “gourmet”. It is just an industry term to sell the product. Let’s look at some label claims:

“Chicken and Liver” - This label is telling the consumer that this food contains 95% meat. For both chicken and liver to be used in the product name, it must contain a combination of chicken and liver to the amount of 95% without counting the water content. Secondly, the percentage of chicken will be greater than liver because chicken is listed first.

“Tuna Dinner” - When the term “Dinner” is used to describe pet food,  AAFCO designates that the product must contain greater than 25% tuna but less than 95% tuna without counting the water content. The consumer cannot tell how much tuna is in the product from the label. Is it closer to the 25% or the 95% content?  A review of the ingredient list is important to determine the actual content. You may find corn is the first ingredient listed and tuna may be the third or fourth item in the ingredient list. Similar words following under the same rule as dinner are Platter, Entree, Nuggets, and Formula.

“Rice and Lamb Dinner” - Should there be two ingredients named in the Dinner such as Rice and Lamb Dinner, the combined named components must exceed 25% of the product content, with the later (rice in this case) not comprising less than 3%.

“With” - A pet food name that includes the word "with", such as “with Cheese” indicates that at least 3% of the product must be cheese according to the AAFCO guidelines. Here the wording on the label is very important. For example a tin of “Tuna Cat Food” must contain 95% tuna, however a tin of “Cat Food with Tuna" must contain merely 3% tuna.

“Flavour” - There is no AAFCO percentage guideline for the use of the word flavour or flavours. However, they do specify that the flavour must be detectable and this is determined in animal taste trials.

“Natural” - There is no official AAFCO definition for the word natural as used on pet food labels. However, AAFCO has set up some guidelines as to what ingredients can be considered “natural”. Basically the word natural “can be construed as equivalent to a lack of artificial flavours, colours or artificial preservatives.”1 Artificial flavours and colours are rarely used in pet food, and natural-source preservatives can be used, however they are not as effective as artificial preservatives.2  

“Organic” - This term pertains to the methods under which animals are raised and plants grown. Although the term is used on pet food labels, there is no official set of guidelines governing organic pet food labels at this time. The Canadian Food and Inspection Agency (CFIA) has defined “organic” with respect to food and drink for human consumption. However, the regulatory requirements do not cover pet food.

“Stew”, “in Sauce”, “in Gravy” - Products with these words in the label have extra water content to provide the appropriate texture and fluidity. The AAFCO guideline for moisture content of most canned pet foods is 78%. Foods labelled with stew, in sauce, or in gravy are allowed to have a moisture content up to 87.5%. If you apply the equations discussed in the pet food article above, "Reading the Pet Food Label - Comparing Apples to Oranges", you will see that the difference in dry matter could be as low as 12% for the “stew” product versus 25% under the regular AAFCO regulations for canned pet foods.
 
    AAFCO has established guidelines to define what constitutes a “low calorie” or “lite” diet. Likewise they have guidelines defining the use of the terms “low fat” and “lean”.

    However, there are many other words found on the pet food labels that have no AAFCO definition or guidelines. Some of these words would be “Premium”, “Gourmet”, “Wholesome”, “Ultra”, “Choice”, “Holistic”, and “Select” to name a few. There is no basis to determine whether pet foods with these terms on the label are of any better quality than any other pet food. They are merely descriptive words used by marketing to bring your attention to that particular product.
    In summary, the terms used on pet food labels are confusing and it is important to read the ingredient list and understand the true content of the pet food.   


Sources:
Dzanis, D. A., Information for Consumers - Interpreting Pet Food Labels, Centre for Veterinary Medicine, 1999.
C.V.M.A Pet Food Misinformation and Fallacies, Of Consuming Interest Newsletter, Issue 7, Summer/Fall, 1997
1,2 Directive 10-02 Scope of the Organic Products Regulations and Use of the Canada Organic Logo from http://www.inspection.gc.ca/english/fssa/orgbio/dir/10-02e.shtml  accessed March 2011

Reading Pet Foods: "The Ingredient List"

    The ingredient list is the one aspect of pet food to which the owners are most sensitive and perhaps find most controversial.  It is wise to be cautious here, but pets are animals and their diet selection is not as refined as our own. Cats hunt down their prey and usually eat most of the carcass including skin, hair, and bones. Canines will often go after the offal (internal organs) and stomach contents first. Their prey is usually animals that forage on grass and grain. It is this carbohydrate rich meal in the stomach that they go after first. Although it may not be to your particular taste or part of your culture, humans do eat organ meat (liver and kidney) and brain, stomach (tripe), and blood sausage. 
    What often happens when pet owners read a pet food label is that they picture the ingredients listed as they would those for their own table. This has led some people to misinterpret the content of these ingredients and denouncing pets foods as unsuitable. The animal diet selection is different than the human diet but that does not make it substandard. Read Farley Mowatt’s “Never Cry Wolf ” for his insights with regard to eating a diet of only lemmings.
    Secondly, the pet owner needs to know that there are regulations that oversee the manufacture and importation of pet foods. In the United States, pet foods are regulated under The Association of American Feed Control Officials (AAFCO). Although "The Canadian Feeds Act" overseen by Canadian Food Inspection Agency (CFIA) does not single out pet foods, it does define and regulate the content of protein feeds and other ingredients that become the ingredients of our pet foods. Comparing the definitions set out by AAFCO and the Canadian Feeds Act, the Canadian Veterinary Medical Association (CVMA) says the following. “Indeed a review of the two sets of definitions indicates that they are very similar if not identical.” (1) Pet food labelling and advertising in Canada is regulated under the Consumer Packaging and Labelling Act and under the Competition Act. The Competition Bureau’s Guide to Labelling and Advertising of Pet Foods was developed by a cross section of interest groups including the CVMA. This guide sets the industry standard for labelling and advertising incorporating “approved statements on nutritional adequacy modelled on the AAFCO” (1) standards. The Competition Bureau monitors all label claims. “Labelling standards require the name of the product, the target animal, the net weight, the name of the responsible party, an ingredient list in decreasing order of concentration, a guaranteed analysis, and feeding instructions.” (1) Definitions were also established for some but not all descriptive terms for pet food. Some of these definitions were discussed in the article above “Reading Pet Food Labels II – What is in the Name”.
    When examining a pet food label the ingredients that alarm pet owners the most are the words meal and by-product. The following definitions are from Schedule IV of The Canadian Feeds Act:

“Animal meat by-products fresh (or Meat by-products)...is the non-rendered, clean parts, other than meat, derived from slaughtered mammals, exclusive of extraneous material such as hair, bones, teeth and hoofs except in such amounts as may occur unavoidably in good manufacturing practice. If it bears a name descriptive of kind, it shall correspond thereto.” (2) (e.g., Chicken by-product).
 
“Animal meat meal rendered (or Meat meal)... is a product obtained by rendering animal tissues, exclusive of hair, hoof, horn, hide trimmings, manure and stomach contents except in such amounts as may occur unavoidably in good manufacturing practice. It shall not contain added blood meal.”
(2)
    False information with regard to these ingredients, have been circulated, claiming that they contain hair, hooves, feathers, and other undesirable parts from the animal. This is not true. Ingredients and labelling are regulated. Knowing what is good for our pets requires education. If you really want to know what is in your pet food become familiar with the Canadian Feeds Act, Schedule IV http://www.inspection.gc.ca/english/anima/feebet/feebete.shtml and the Canadian Nutrition Assurance Program of the Pet Food Association of Canada found at http://www.pfac.com/learn/industry/index.html

    Although each label is required to show a guaranteed analysis, this does not give the true quality of a pet food. Two foods that have the same guaranteed analysis may be in reality quite different in nutrient value. This is because a minimum content requirement of 8% may be met and exceeded. The product may legally be able to contain 15% of that nutrient. Likewise a maximum requirement of 5% of a nutrient may in reality be only 2%. The best way to evaluate a product is to call the manufacturer and ask for the actual nutrient content of the food you have purchased. Not every client will desire to track down the actual content of their pet’s food.
    Instead, examine the label for the AAFCO nutritional adequacy statement or a quality assurance claim. The AFFCO statement verifies that the pet food provides a complete and balanced diet for the particular life stage for which that food was designed. If there is no AAFCO statement there should be a quality assurance claim. Good quality pet foods will have a quality assurance program and will meet or exceed the AAFCO standard for pet food.
    Foods claiming to be suitable for all life stages should be viewed as suspect. Puppies and kittens, pregnant and nursing mothers will have different nutrient requirements than adult animals. The nutrient requirements may exceed those required by an adult or senior pet in order to claim it is suitable for young growing animals, pregnant or nursing mothers.
    The whole realm of pet nutrition is very complex. There are many manufacturers out there trying to get a piece of the pet food market. Each will try to attract the consumer with various claims and niche marketing terms. It is the consumer’s responsibility to try and decipher the labelling to determine the best food for their pet. In their search for answers, the owner should discuss their pet’s nutritional needs with their pet’s health care team. They are the most knowledgeable in pet nutrition and the best resource for nutritional information.

1. Something to Chew ON! Pet Food Regulation In Canada, pamphlet published by C.V.M.A., 2003.
2. Canadian Feeds Act, Schedule IV. http://www.inspection.gc.ca/english/anima/feebet/feebete.shtml accessed August 25, 2011.
3. Pet Food Misinformation and Fallacies. Of Consuming Interest, C.V.M.A. Issue 7, Summer/Fall 1997.
4. Parcells, J. What’s for Dinner? Pet Commerce, June/July 1999.
5. Watson, H. Complete and Balanced. Dogs in Canada, March 1999.
6. How to read a pet food label, pamphlet published by Hill’s Pet Nutrition Canada, 2007.

Comments