Is My Dog Food Low in Carbs?

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imageLast week we talked about the role of carbohydrates in a dog’s diet, their benefits and sources. Today we will show you how to determine the carbohydrate amount in your dog’s food so that you can easily assess whether your dog food is providing the needed energy requirements from the proper sources.

Let’s start by looking at the typical food label “crude analysis” which displays the relative amounts of the macro nutrients.  Most labels show you the percentages for the following:

  • Protein
  • Fat
  • Fiber
  • Moisture

As you can see, there is no mention of the carbohydrate content.  Some say that this is a nefarious omission by the dog food industry to obfuscate the fact that the food is carbohydrate laden due to the preponderance of lower quality ingredients.   Today, we will leave that argument for others and focus instead on how to calculate the carbohydrate value.

Before we show the calculation, we must take a side step and discuss another ingredient that isn’t often listed, Ash.  The ash content in a food is needed to more accurately estimate the carbohydrate content.

What is Ash?

Ash is the inorganic material that remains after organic material is burnt up.  Ash is made up of mineral nutrients like calcium, phosphorous, zinc, iron, etc.   Ash itself is not necessarily bad– most ash comes from the bone content and minerals additives in a product.  In general, dry pet food is always going to contain ash content while wet food will occasionally have it in smaller amounts.

Though essential, there are a few situations where high ash quantity in food can be harmful.  For example, dogs with crystals in their urine, and large breed puppies are two cases where the ash content needs to be appropriately reduced.  Check with your vet to make sure that you dog is not especially sensitive to high ash content.

These days, the ash content is not often displayed on the food label.  If it is, you will use that value when doing the carbohydrate calculation.  If the ash content is not explicitly stated on the label, according to “Applied Veterinary Clinical Nutrition”, Andrea J. Fascetti, Sean J. Delaney, you can use an estimate of 2.5% for canned food and 8%  for dry food.

Calculating Carbohydrate Content

The calculation of carbohydrate content is a simple 2 step process.  The first step is to estimate the percentage of carbohydrates on an as fed basis, and the second step is to convert it to a dry matter basis (which adjusts for water content).  We will use the example label below in our calculations.

 guaranteed analysis_lg


Step 1- The protein, fat, carbohydrate, ash and moisture content account for almost 100 percent of the total pre-cooking weight of any dog food.  By subtracting the protein, fat, water and ash percentages from the 100 percent total, you will have a decent estimate of the total carbohydrate content.  Using our example above:

100-26-16-10-7.5= 40.5% carbohydrates.

Note that the fiber is not included in this calculation because it comes from carbohydrates so it is already a part of the carbohydrate total.

Step 2- Convert to dry matter basis- this steps allows you to compare dry food and canned food as it adjusts for water content.  As we explained in a prior post, the dry matter calculation is a simple ‘re-basing’ of the nutrient profiles after removing the water content.

Using our example above, we re-base by taking the carbohydrate amount from above and divide by the dry matter (100%-10% moisture = 90% or .9).  Here are the results for the main macro nutrients.

macro nutrients

The net result of these calculations is that this example food is 45% carbohydrate on a dry matter basis.  Most dog foods have a carbohydrate percentage between 30-70%, with higher values normally associated with lower quality foods that use grains and other low cost fillers to provide a disproportionate amount of the foods energy benefit.

What does this all mean for my dog?

First of all, remember that many dog food labels do not report ash in the guaranteed analysis. Use 2.5% and 8% ash values for canned and dry foods respectively if this is your case.

Secondly, we recommend that you check with your vet to make sure that your dog has no special dietary needs (e.g. protein or ash maximums).

Lastly, and assuming no special diet needs, we stick with our premise that dogs are best fed a diet high in protein and moderate in fat.  In this case, stick with foods whose carbohydrate values are closer to 30% than to 70%.


References and further reading:

“Applied Veterinary Clinical Nutrition”, edited by Andrea J. Fascetti, Sean J. Delaney

We’re joining the Tasty Tuesday Blog Hop sponsored by Sugar, the Golden Retriever and Kolchak from Kol’s Notes:

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  1. Golden Thanks. We will definitely ask our vet. I am a senior dog and have to be extra careful. Happy Tasty Tuesday. Lots of Golden Woofs, Sugar
    SUGAR: Golden Woofs recently posted…Tasty Tuesday: Kong Treats In The Kong WobblerMy Profile

  2. Omigoodness. I don’t buy good dog food. I know I don’t. My babies, at eleven, are very healthy. I think it’s probably because they supplement with duck and chicken and rabbit poo. Oh, and Jones Natural Chews, which are high in protein.
    Flea recently posted…Treat ReviewsMy Profile

  3. Ahhh….here you go with the confusing math for that 🙂 I am not sure I will every be able to wrap my little brain around that. Maybe you should make an app for that too 🙂
    Jessica recently posted…Homemade Energy Bars Both You and Your Dog Can EatMy Profile

  4. Good job on the article. With kibble, it is quite hard to find low-carb kibble, because relatively high amount is needed just for kibble to become kibble.
    Jana Rade recently posted…Veterinary Highlights: Evaluating Dog ArthritisMy Profile

  5. Awesome post… I’m off to do some math… hope I get it right!
    Pam recently posted…Tuesday’s Tails: Featuring HanaMy Profile

  6. That’s a lot of math. Luckily I’m good with numbers! It’s an important calculation that everyone should do though.

    Back when we were battling Felix’s allergies and food intolerances, we tried finding a “low carb” kibble and it was nigh to impossible. It takes a certain amount of carbs for the kibbles to hold their shape during extrusion. Knowing that dogs have no nutritional need for carbs (they can process them and use them, but they are also fine without them) helped us feel better about our switch from kibble.
    Kolchak, Felix & Jodi recently posted…Wordless Wednesday: #DogBeardingMy Profile

    • Just being knowledgeable about what important and what’s isn’t outside of the noise is important. It’s good you knew enough to know what would work for Kol.

  7. I’ve been wondering about ash content lately. I wrote an article on examiner about bully sticks and noticed that the ingredients on the list included ash. Thanks for sharing!
    Ann “Paws” Staub recently posted…Reptile VisitorsMy Profile

    • It’s kind of amazing the things you learn when you really start looking into the ingredients and what they actually are.

  8. So, I am thinking that big chunk of French bread I stole off the counter last night was probably full of carbs??? It is all so confusing like a jumbo story problem in math class. Mom says that if she really thinks hard about what she needs to eat and we need to eat we would never get around to eating! Luckily we don’t have special dietary needs and we buy high quality chow so hopefully we will come out ok. Never thought about ash at all, figured it was what was left after a fire end of the story. Great job explaining this all!
    emma recently posted…The Tale of the Pirate Frog | GBGV | Wordless WednesdayMy Profile

  9. This is interesting to know. The raw food we feed our dogs is low in carbs; but the protein isn’t as high as I would think considering that it’s raw meat. This is going to be fun to translate what I’m learning here to the raw food diet!
    Kimberly, The Fur Mom recently posted…A New Site About Raw Dog Food by the Blogger of Keep the Tail WaggingMy Profile

  10. This is article is dead on, Now I’ll try to do the math. I have been paying more carefull attention to my dog food labels lately since the last recall on Natura’s Pet Food products.
    Is too much ash bad?

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