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Nutrition Nuggets
 
 
Your dog's nutrition is important for a healthy & happy life. petMD experts help you to know what to feed your dog, how much food to feed, and the differences in dog foods, so your dog gets optimum nutrition.
Nutrition Nuggets is the newest offshoot of petMD's Dog Nutrition Center. Each week Dr. Coates will use her expertise and wisdom to blog about the intricacies of dog nutrition.

What a Guaranteed Analysis Can (and Can't) Tell You About a Dog Food

September 23, 2011 / (2) comments

Dog owners are in search of information about appropriate food choices for their pets. You can turn to family and friends for their recommendations, but keep in mind that what works well for one individual is not always the best choice for another.

Your veterinarian is another good source of information, of course, and so are reputable internet sites like the PetMD Nutrition Center and the MyBowl tool. But don’t overlook something that is probably close at hand: the label covering your dog’s bag of food.

Dog food labels contain a lot of information. The article Demystifying the Dog Food Label provides a good overview of what legally must be included, but doesn’t go into much detail about the guaranteed analysis. Let’s take a closer look at this useful resource.

To begin with, this is what a guaranteed analysis tends to look like:

This example provides significantly more information than many pet food labels do. By law, all a manufacturer has to report are the minimum amounts of protein and fat and the maximum amounts of water (moisture) and fiber that are in the diet. Including information about vitamin, mineral, and essential fatty acid levels is an added bonus.

But the raw data from the guaranteed analysis only gets you so far. To compare different dog foods that contain very different amounts of water (e.g., canned and dry formulations), as well as evaluating how a particular food measures up to the nutrient levels for dogs recommended in the MyBowl tool, you’ll need to compensate for the "dilution" caused by the moisture in the food. This requires a little math. (Have no fear, the calculations aren’t too tough!)

First, find the percent moisture that is reported in the guaranteed analysis, and subtract that number from 100. This is the percent dry matter for the food. Next divide the nutrient percentage on the label that you are interested in by the percent dry matter for the food and multiply by 100. The resulting number is the nutrient percentage on a dry matter basis. For example, if a label lists the crude protein minimum at 21% and the moisture maximum at 10%, the calculations would be as follows:

100-10=90 and then 21/90 x 100 = 23% protein on a dry matter basis

So with a small investment of time and brain power, you now have some very useful information about whether or not a food provides properly balanced nutrition for your dog. And it all came right off the bag (or can) itself!

Dr. Jennifer Coates

Image: brian hefele / via Flickr

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Comments  2

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  • dog food
    09/22/2011 06:02pm

    they keep telling me my puggel has food allergys because he starts of with pustual red dots then they turn black.i've already spent thousands on tests and medication but there not going away.I even changed his food to california natural.but nothing is working now i am try the advice i got from this web sight by cleasing him weekly with benzoyl perozide wash do you think it will help his stomach on bottom looks really bad i'm at my wits end .i keep him very clean he is a house dog goes out to do his duty hes very well trained.no fleas he gets all his medications ,and still on his undercoat this black spots. help. please any answers? lovespugs. you can email me at jbrown6790@gmail.com

  • Min-Max
    09/23/2011 06:42am

    Guaranteed analysis tells you something, but not much.
    Better to email company and ask for "as fed" analysis and see if they are forthcoming. Sometimes it's like pulling teeth to get this info.

    For the minerals one really needs to know the maximum too, since the ratio of Ca:P is important.

    While AAFCO has set max for Ca for dogs, there's none for cats, so who knows what the ratio of Ca:P is in foods unless you ask.

 



ABOUT NUTRITION NUGGETS

JENNIFER COATES, DVM

Photo of Jennifer

... graduated with honors from the Virginia-Maryland Regional College of Veterinary Medicine in 1999. In the years since, she has practiced veterinary medicine in Virginia, Wyoming, and Colorado. She is the author of several books about veterinary medicine and animal care, including the Dictionary of Veterinary Terms, Vet-Speak Deciphered for the Non-Veterinarian .

Jennifer also writes short stories that focus on the strength and importance of the human-animal bond and freelance articles relating to a variety of animal care and veterinary topics. Dr. Coates lives in Fort Collins, Colorado with her husband, daughter, and pets.

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