In our last post, we looked at things that should and should not be found in dog food. In this second part of our series on the maze of dog food selections, we look at the value of protein, carbs and other ingredients in a dog food.
Starting with protein –
High levels of protein are recommended for dogs with high activity levels and/or high stress levels. Heavy dogs may loose more weight on a high protein, low carb diet than a diet with more carbs but less calories. For dogs with kidney disease, a high quality, low protein diet is suggested. Typically, a good quality food for the average adult dog is 21-24%. But it is the quality of the protein that is important here. (see previous post). When comparing protein percentages between canned food and dry food, you must first convert both to what is called Dry Matter. To do this, take 100% and subtract the water percent listed on the product then divide the protein percent by this amount and multiply by 100. (Example: In the guaranteed analysis section on a can of dog food, water content is 80%, protein is 10%. Take 100% minus 80% leaves 20% of dry matter. Divide the 10% protein by the 20% dry matter, and multiply by 100 and you get 50%. This is the dry matter protein. Doing this to both dry and canned yields a protein amount that you can use to compare.
For dogs that live in very cold environments, or hard-working dogs, chronically thin dogs, and dogs with cancer, a higher fat diet is appropriate. The typical amount of fat in a good quality adult dog food is 15-19%.
Increases and decreases in opposite direction of protein. The only thing to remember is that the higher the carbs, the more likely it can cause fluctuations in blood sugar and insulin resistance – obviously not appropriate for diabetic dogs or dogs prone to diabetes or dogs with cancer (who need high fat and low to no carbohydrates). Dogs do not really require high carbs as an energy source. In small amounts, they are fine, but watch out for foods that favor carbs over protein and fat. Unfortunately, the carbohydrate content is never listed on a dog food label. But you can do some simple math: The protein, fat, ash, water and carbs must equal 100% of pre-cooking weight. So, take 100% and subtract the protein, fat, ash, and water – the rest is carbs! (If ash amount isn’t listed, you can estimate between 5% and 8% ash).
Calcium and Phosphorus –
Usually fluctuates in the same direction as protein levels. Higher levels can affect the digestibility of a food, zinc absorption and can cause bone abnormalities in puppies especially large-breed puppies. These minerals should be kept as low as possible for puppies and dogs with kidney disease.
This is what is left over after the food is burned in an incinerator and is mostly potassium and phosphorus along with calcium, iron, magnesium, sodium, and zinc. The higher the ash level, the higher the mineral content (remember phosphorus is bad for dogs with kidney disease).
Avoid high calorie diets for large and/or giant breed puppies. Grain free diets can be high in calories. The protein has to be carefully controlled if feeding a high calorie diet to any dog.
For a complete discussion on pet food labels go to:
Next time, we will discuss the pros and cons of the different types of dog food available.