We can all assume that wet dog food, like the Purina dog food (Purina Pro Plan Dog Food), has more water or moisture than dry dog food like the Royal Canin Dog Food. However, how much water is really in your dog food? And what does that mean about the presence of all the other ingredients?
Moisture is the water content of dog food, as expressed in a percentage. Dry kibble tends to have a moisture content of between 6 and 10 percent, semi-moist foods between 15 and 30 percent, and wet foods such as the Beneful Chopped Blend Dog Food Tubs around 75 percent. As expected, there is more water in wet dog food than in dry.
Does Moisture Matter?
The moisture content affects the percentages of other ingredients in dog food, including the amounts of protein, carbohydrates, and fats. Pet caregivers often want to compare dog foods based on how much protein they contain. Comparing the data in the guaranteed analysis section of a label may not be the whole story.
The guaranteed analysis tells you how much of the total percent of the food comes from protein, fat, fiber, and moisture. If we remove the moisture element, the percentages of the other substrates, like fat and protein, will increase dramatically.
If moisture content were the same for every dog food, we’d be comparing one food to another on the same ground. As it is, the difference in moisture content among foods is great. So, to get a more accurate picture of the nutritional value of dog food, specifically the protein content, we should explore what would happen if we were to squeeze all the moisture out. What’s leftover may surprise you.
The Dry Matter Basis
Knowing how to calculate the percentage of protein minus the moisture content will give you a much better picture of the real protein content of any dog food.
Even the FDA agrees. They say, “The weights of ingredients are determined as they are added in the formulation, including their inherent water content. This latter fact is important when evaluating relative quantity claims, especially when ingredients of different moisture contents are compared.” Consider seeing a package that has chicken as the number one ingredient, which is about 60% moisture, versus a chicken meal that has less than 10% moisture. Which has more protein?
What a Pain!
Yes. Sometimes manufacturers really don’t make it easy on the consumer. Being committed and savvy is all part of being a great pet parent. By doing the calculations, you figure out what pet food companies are really adding. And the math isn’t too tricky.
The Math to Remove The Moisture Content
-
First, we’ll figure out the dry matter in wet dog food. Begin by assuming we’re starting at 100%. This 100% is the whole dog food and everything in it.
-
100% (gee, this is easy!)
-
Subtract the percentage of moisture, as listed on the can. So if the can lists a 75% moisture content, you’re left with 25% dry matter.
-
100% (everything) - 75% (moisture) = the canned food in question is made up of 25% dry matter
-
The next question we’re concerned with is: how much of that dry matter is actually protein? To figure this out, we’ll divide the amount of protein listed in the guaranteed analysis by the total amount of dry matter. Then we’ll multiply the whole thing by 100. Let’s say guaranteed analysis lists protein at 10%.
-
10 (protein) / 25 (dry matter) = 0.4
-
0.4 x 100 = 40%
What we’ve learned is that this canned food has a protein content of 40 percent on a Dry Matter Basis.
When you do the same calculations with dry kibble of 10 percent moisture and 25 percent guaranteed analysis protein, you get a dry matter protein of only 28 percent.
Quite a difference, right? The wet food has nearly double the protein content. It could be worth combining the two to get your dog a bit more protein in his diet.
Choosing a Quality Food
High-quality dog food will have all the protein and other ingredients your dog needs to stay healthy. Good food for your pet will have a substantial dry matter protein content, typically above 20%.
However, every dog may require different amounts of protein, calcium, and fat depending on its breed, age, activity levels, and other factors. Knowing a dog food’s moisture content will let you determine its major nutrient composition compared to other foods.
Should Fiber Be in Dog Food?
Most of us know by now how important fiber is to our diets. The makers of high-fiber cereal, as well as our doctors, have made clear the many health benefits of a diet high in fiber. But is fiber in dog food important as well?
The answer is yes. In many of the same ways that fiber promotes our own health, the fiber in a dog’s diet will help improve stool quality and colon health, promote weight loss or maintenance and even help to regulate blood sugar levels.
Benefits of Fiber
Fiber is a form of carbohydrate and, in most diets, is composed largely of the cell walls of plants. These cell walls are indigestible, meaning that they move through the digestive tract intact and are not dissolved by the enzymes and acids that break down other food components like protein and fat.
Because fiber is indigestible, it helps to regulate the movement of food and waste through the small and large intestines. Fiber tends to prolong the digestive process by slowing things down a bit, allowing the digestive tract to do its job of extracting nutrients from the food and efficiently eliminating what the body doesn’t need through the dog’s stool.
A dog that receives enough fiber in its diet in the right form, but not too much, will have better digestive health. At the same time, you’ll notice an improvement in your dog’s stool, which will be firm and well-formed, not loose or pasty. This is not only good for your dog but good for you come clean-up time!
At the same time, fiber can help your dog maintain a proper weight. By adding bulk to food without the addition of calories, a high-fiber meal will make your dog feel full and satisfied with less caloric intake. That's why many dry dog food brands like the Purina Pro Plan Puppy Lamb And Rice add brewer's rice and grains to ensure there is enough fiber.
Those dogs that have or are prone to diabetes will also benefit from a diet that is well balanced with fiber. Fiber allows the body to absorb sugar from the diet more slowly, which helps maintain stable blood sugar levels, a key component of proper diabetes management.
Is your dog getting enough fiber?
There are several signs you can look for that will tell you your dog might not be getting enough fiber.
If your dog tends to strain during defecation, this might be a sign that more fiber is warranted. Dogs that scoot along the floor, rubbing their rear ends along the carpeting, could be having trouble expelling their anal glands. The fiber in your dog’s stool may help stimulate these glands and relieve the uncomfortable pressure.
Dog owners should be aware that although fiber in its proper proportion is good for your dog’s health, too much fiber can cause problems itself. Dogs with an overabundance of dietary fiber can develop soft stools. This is often due to too much of a specific kind of fiber called “soluble” fiber. High-quality dog food will typically contain the right proportion and type of fiber for your pet, although consultation with your vet will help ensure your dog is getting just what he or she needs.
Frequently Asked Questions
Is moisture good in dog food?
What does moisture in dog food mean?
Which moist dog food is best?
What can I use to moisten my dog's food?
Do vets recommend wet or dry food?
Back to Your Dog Food Questions Answered
Previous: What Is Ash in Dog Food?
Next: Should Fiber Be in Dog Food?
This information is for informational purposes only and is not meant as a substitute for the professional advice of, or diagnosis, or treatment by, your veterinarian. It has however been reviewed for accuracy by Dr. Joe, a board-certified veterinary nutritionist and graduate of Cornell University's program for Veterinary Medicine.