CynthiaATL
Member
LCummings School of Veterinary Medicine
Tufts University, North Grafton, MA
One of the most common questions veterinarians get from pet owners is "What's the best food for my dog (or cat)?†With the hundreds of pet foods available today, it has become a more complicated question than it once was. Nor is there one simple answer since the "best" food for a pet depends on many factors, such as life stage, body condition, exercise (or lack thereof), environment, and health status. Often, owners base their decisions on marketing, rather than on objective nutritional nformation. Although there are limitations to the information provided on a pet food label, the label can provide important information to help in selecting foods.
GUARANTEED ANALYSIS
The guaranteed analysis is required to give only the minimum content of protein and fat in the food and the maximum content of fiber and moisture. Other nutrients may also be listed but are not required. This obviously is only a limited number of the nutrients you might be interested in and, in addition, having the minimum or maximum level of a nutrient might not provide all the information you need (for example, in a dog that requires dietary fat restriction, a minimum fat level of 3% listed on the label does not tell you exactly how much fat the diet contains (it might contain 3% but it might contain more). Another issue that commonly confuses pet owners is that the nutrient levels in the guaranteed analysis are listed on an "as fed" basis, which includes the water in the food (therefore, the protein level of a dry food will appear to be much higher than the protein level in a canned food, even if the levels on a dry matter basis are exactly the same). To compare diets to one another, you must change the numbers to a "dry matter" basis (which is the content of the nutrients without any water). The quick rule of thumb for making this conversion is as follows:
For a canned food, multiply the guaranteed analysis content for the nutrient in question by 4. Therefore, a canned food that contains a minimum of 10% in the guaranteed analysis actually contains a dry matter protein content of approximately 40%.
For a dry food, multiply the guaranteed analysis number by 1.1. Therefore, a dry food that contains a minimum of 36% protein on the label also has a dry matter protein content of approximately 40%. If you want the exact nutrient content or information on nutrients not listed, call the manufacturer whose name and address must be listed on the label. The contact information for the manufacturer is one of the most useful pieces of information on the label. A company should be able to provide any other nutritional information that you might require for your patients. If a company cannot or will not provide you with a piece of nutritional information, I would consider that to be a red flag and would not recommend that food!
INGREDIENTS
Ingredients must be listed on the label in decreasing order by weight. Some owners are concerned about using diets that contain any vegetable-based proteins, such as soybean or corn. While these are useful protein sources, it is wise to be sure an animal product is one of the first three ingredients in a food. Pet food ingredients have strict definitions so meat byproducts, for example, they are not allowed to contain the non nutritious anima parts that people sometimes worry about. Be aware though, that these legal definitions only define the composition of the ingredient, not its quality. There are good quality and poor quality meat byproducts as well as good quality and poor quality meats. The quality of meat byproducts and other ingredients can be assured by using foods made by reputable companies (not just the ones with the most persuasive marketing). Getting information on the food's digestibility also can be helpful because digestibility will generally be lower when poor quality ingredients are used.
NUTRITIONAL ADEQUACY
A pet food that is intended as a complete and balanced diet must be established as such in one of two ways: 1) By formulation to meet the levels established by the Association of American Feed Control Officials (AAFCO) or 2) by feeding trials. A diet that is only formulated contains nutrients in amounts that meet AAFCO profiles but the diet has not gone through feeding trials. Therefore, unforeseen problems with bioavailability or nutrient interactions could arise. Feeding trials provide better assurance that the food meets a dog's or a cat's requirements. Although AAFCO feeding trials have their limitations, they should be a minimum level of assurance. When feeding trials have been performed, the label should read, "Animal feeding tests using AAFCO procedures substantiate that Brand X provides completed and balanced nutrition for growth (or maintenance).†If the food is only formulated to meet requirements, the label must read, "Brand Y is formulated to meet the nutritional levels established by the AAFCO Dog (or Cat) Food Nutrient Profiles…†Therefore, the nutritional adequacy statement provides two important pieces of information: 1) Which life stage profile the food meets and 2) how this statement was substantiated. Pet foods are designed to meet the minimums for one of the recognized life stages: growth and reproduction or adult maintenance. Foods that are complete and balanced for all life stages meet the requirements for growth, reproduction, and adult maintenance. Be aware that the life stage a food is marketed for may not necessarily be the same stage for which the food is truly meets the minimums. For example, many diets marketed for adult cats actually meet the profiles for all life stages so they have nutrient levels high enough to be fed to kittens or lactating queens. By checking the nutritional adequacy statement, owners can select a food that is most appropriate for their pets' life stage.
FEEDING DIRECTIONS
Pet food labels must list feeding directions. Mostfeeding guidelines overestimate the amount a dog or catshould eat (although some of the pet food companiesare beginning to revise their labels to contain morereasonable estimates). Therefore, feeding directionsshould be used only as a starting point and owners mustmake adjustments to keep the pet in trim body condition.
CALORIE CONTENT
It seems obvious that the calorie content of the food would be on the label but this is not required information (except for "light" foods; see below). The calorie information is allowed on the label and some pet food companies are starting to include the calorie content. This is very helpful information to be able to compare foods. If calorie information is not on the label, it can be obtained either from the company’s website or by calling them. Calories (and any other nutritional information) should be readily provided by the company.
DESCRIPTIVE TERMS
There are now maximum caloric densities for foods that are described as "light," "lite," or "low calorie" (for
example), a dry dog food must contain < 3100 kcal/kg). In addition, when a food is described as such, the label must contain a calorie content statement. However, the requirement for the calorie statement is that it must be expressed as kcal/kg of food (obviously, not very useful to the pet owner) and may also be expressed as kcal/cup or kcal/can. One of the other difficulties with this regulation is that even if a food is <3100 kcal/kg, it may still contain more calories per cup than desired. There is tremendous variability in calorie density per cup or can of food even when comparing so-called low calorie foods so careful attention must be taken to avoid excessive calories. "Lean" or "low fat" diets must contain below a certain percentage of fat and also must include the maximum crude fat level in the label's guaranteed analysis (and be aware that lean or low fat diets are not necessarily low in calories). The guidelines for the use of "natural" on pet food labels are that the product should not contain any chemically synthesized ingredients. Exceptions can be made when chemically synthesized vitamins or minerals are used as long as there is a disclaimer on the label (eg, "natural with added vitamins and minerals."). Other descriptors, such as "holistic," “organic,†"gourmet," and "human grade" have no legal definition for pet foods and are primarily marketing terms. In general, the recommendations for selecting a good quality pet food are as follows:
Feed a pet food manufactured by a well-known, reputable company.
Feed a complete and balanced food for the appropriate life stage of the pet (growth diet for puppies or kittens, maintenance diet for adults) – this should be substantiated by feeding trials. Remember that pets are individuals and may respond better to one diet than to another.
NUTRITION RESOURCES
1. American Academy of Veterinary Nutrition, www.aavn.org
2. American College of Veterinary Nutrition, www.acvn.org
3. American College of Veterinary Nutrition Resources (nutritional consultations with Diplomates of the American College of Veterinary Nutrition, including homemade diets),
<A href="http://www.aavn.org/site/" target=_blank>[URL="http://www.aavn.org/site/view/58440_Nutrition20Resources.pml;jsessionid=h8qpdmib0tfp9"]http://www.aavn.org/site/[/URL]view/58440_Nutrition20Resources.pml;jsessionid=h8qpdmib0tfp9
4. Association of American Feed Control Officials, www.aafco.org
5. FDA Center for Veterinary Medicine, www.fda.gov/cvm
6. FDA Recall List, [URL="http://www.fda.gov/opacom/7alerts.HTML"]http://www.fda.gov/opacom/7alerts.HTML[/URL]
7. Ohio State Nutrition Support Service, http://www.vet.ohio-state.edu/nssvet.htm
8. Pet Food Institute, www.petfoodinstitute.org
9. Pet Food Institute Consumer Guide, www.petfoodreport.org
Tufts University, North Grafton, MA
One of the most common questions veterinarians get from pet owners is "What's the best food for my dog (or cat)?†With the hundreds of pet foods available today, it has become a more complicated question than it once was. Nor is there one simple answer since the "best" food for a pet depends on many factors, such as life stage, body condition, exercise (or lack thereof), environment, and health status. Often, owners base their decisions on marketing, rather than on objective nutritional nformation. Although there are limitations to the information provided on a pet food label, the label can provide important information to help in selecting foods.
GUARANTEED ANALYSIS
The guaranteed analysis is required to give only the minimum content of protein and fat in the food and the maximum content of fiber and moisture. Other nutrients may also be listed but are not required. This obviously is only a limited number of the nutrients you might be interested in and, in addition, having the minimum or maximum level of a nutrient might not provide all the information you need (for example, in a dog that requires dietary fat restriction, a minimum fat level of 3% listed on the label does not tell you exactly how much fat the diet contains (it might contain 3% but it might contain more). Another issue that commonly confuses pet owners is that the nutrient levels in the guaranteed analysis are listed on an "as fed" basis, which includes the water in the food (therefore, the protein level of a dry food will appear to be much higher than the protein level in a canned food, even if the levels on a dry matter basis are exactly the same). To compare diets to one another, you must change the numbers to a "dry matter" basis (which is the content of the nutrients without any water). The quick rule of thumb for making this conversion is as follows:
For a canned food, multiply the guaranteed analysis content for the nutrient in question by 4. Therefore, a canned food that contains a minimum of 10% in the guaranteed analysis actually contains a dry matter protein content of approximately 40%.
For a dry food, multiply the guaranteed analysis number by 1.1. Therefore, a dry food that contains a minimum of 36% protein on the label also has a dry matter protein content of approximately 40%. If you want the exact nutrient content or information on nutrients not listed, call the manufacturer whose name and address must be listed on the label. The contact information for the manufacturer is one of the most useful pieces of information on the label. A company should be able to provide any other nutritional information that you might require for your patients. If a company cannot or will not provide you with a piece of nutritional information, I would consider that to be a red flag and would not recommend that food!
INGREDIENTS
Ingredients must be listed on the label in decreasing order by weight. Some owners are concerned about using diets that contain any vegetable-based proteins, such as soybean or corn. While these are useful protein sources, it is wise to be sure an animal product is one of the first three ingredients in a food. Pet food ingredients have strict definitions so meat byproducts, for example, they are not allowed to contain the non nutritious anima parts that people sometimes worry about. Be aware though, that these legal definitions only define the composition of the ingredient, not its quality. There are good quality and poor quality meat byproducts as well as good quality and poor quality meats. The quality of meat byproducts and other ingredients can be assured by using foods made by reputable companies (not just the ones with the most persuasive marketing). Getting information on the food's digestibility also can be helpful because digestibility will generally be lower when poor quality ingredients are used.
NUTRITIONAL ADEQUACY
A pet food that is intended as a complete and balanced diet must be established as such in one of two ways: 1) By formulation to meet the levels established by the Association of American Feed Control Officials (AAFCO) or 2) by feeding trials. A diet that is only formulated contains nutrients in amounts that meet AAFCO profiles but the diet has not gone through feeding trials. Therefore, unforeseen problems with bioavailability or nutrient interactions could arise. Feeding trials provide better assurance that the food meets a dog's or a cat's requirements. Although AAFCO feeding trials have their limitations, they should be a minimum level of assurance. When feeding trials have been performed, the label should read, "Animal feeding tests using AAFCO procedures substantiate that Brand X provides completed and balanced nutrition for growth (or maintenance).†If the food is only formulated to meet requirements, the label must read, "Brand Y is formulated to meet the nutritional levels established by the AAFCO Dog (or Cat) Food Nutrient Profiles…†Therefore, the nutritional adequacy statement provides two important pieces of information: 1) Which life stage profile the food meets and 2) how this statement was substantiated. Pet foods are designed to meet the minimums for one of the recognized life stages: growth and reproduction or adult maintenance. Foods that are complete and balanced for all life stages meet the requirements for growth, reproduction, and adult maintenance. Be aware that the life stage a food is marketed for may not necessarily be the same stage for which the food is truly meets the minimums. For example, many diets marketed for adult cats actually meet the profiles for all life stages so they have nutrient levels high enough to be fed to kittens or lactating queens. By checking the nutritional adequacy statement, owners can select a food that is most appropriate for their pets' life stage.
FEEDING DIRECTIONS
Pet food labels must list feeding directions. Mostfeeding guidelines overestimate the amount a dog or catshould eat (although some of the pet food companiesare beginning to revise their labels to contain morereasonable estimates). Therefore, feeding directionsshould be used only as a starting point and owners mustmake adjustments to keep the pet in trim body condition.
CALORIE CONTENT
It seems obvious that the calorie content of the food would be on the label but this is not required information (except for "light" foods; see below). The calorie information is allowed on the label and some pet food companies are starting to include the calorie content. This is very helpful information to be able to compare foods. If calorie information is not on the label, it can be obtained either from the company’s website or by calling them. Calories (and any other nutritional information) should be readily provided by the company.
DESCRIPTIVE TERMS
There are now maximum caloric densities for foods that are described as "light," "lite," or "low calorie" (for
example), a dry dog food must contain < 3100 kcal/kg). In addition, when a food is described as such, the label must contain a calorie content statement. However, the requirement for the calorie statement is that it must be expressed as kcal/kg of food (obviously, not very useful to the pet owner) and may also be expressed as kcal/cup or kcal/can. One of the other difficulties with this regulation is that even if a food is <3100 kcal/kg, it may still contain more calories per cup than desired. There is tremendous variability in calorie density per cup or can of food even when comparing so-called low calorie foods so careful attention must be taken to avoid excessive calories. "Lean" or "low fat" diets must contain below a certain percentage of fat and also must include the maximum crude fat level in the label's guaranteed analysis (and be aware that lean or low fat diets are not necessarily low in calories). The guidelines for the use of "natural" on pet food labels are that the product should not contain any chemically synthesized ingredients. Exceptions can be made when chemically synthesized vitamins or minerals are used as long as there is a disclaimer on the label (eg, "natural with added vitamins and minerals."). Other descriptors, such as "holistic," “organic,†"gourmet," and "human grade" have no legal definition for pet foods and are primarily marketing terms. In general, the recommendations for selecting a good quality pet food are as follows:
Feed a pet food manufactured by a well-known, reputable company.
Feed a complete and balanced food for the appropriate life stage of the pet (growth diet for puppies or kittens, maintenance diet for adults) – this should be substantiated by feeding trials. Remember that pets are individuals and may respond better to one diet than to another.
NUTRITION RESOURCES
1. American Academy of Veterinary Nutrition, www.aavn.org
2. American College of Veterinary Nutrition, www.acvn.org
3. American College of Veterinary Nutrition Resources (nutritional consultations with Diplomates of the American College of Veterinary Nutrition, including homemade diets),
<A href="http://www.aavn.org/site/" target=_blank>[URL="http://www.aavn.org/site/view/58440_Nutrition20Resources.pml;jsessionid=h8qpdmib0tfp9"]http://www.aavn.org/site/[/URL]view/58440_Nutrition20Resources.pml;jsessionid=h8qpdmib0tfp9
4. Association of American Feed Control Officials, www.aafco.org
5. FDA Center for Veterinary Medicine, www.fda.gov/cvm
6. FDA Recall List, [URL="http://www.fda.gov/opacom/7alerts.HTML"]http://www.fda.gov/opacom/7alerts.HTML[/URL]
7. Ohio State Nutrition Support Service, http://www.vet.ohio-state.edu/nssvet.htm
8. Pet Food Institute, www.petfoodinstitute.org
9. Pet Food Institute Consumer Guide, www.petfoodreport.org
