Switching It Up
Provide a variety of foods to delight your dog's taste buds and offer a nutritionally complex diet.
Dog World article by Mary Straus, published in Dog World Magazine, January 2011.
For years, conventional wisdom claimed that you should feed your dog one food for its entire life, but this advice is now in question. We would never feed ourselves that way; why are our dogs any different?
Nutrition is not an exact science
Our knowledge of pet nutrition has changed over time. “Unless a veterinarian has recommended a hypoallergenic diet for your pet, it is best to vary the diet,” says veterinarian Susan Wynn, D.V.M., who writes, teaches and speaks on the subject of clinical nutrition.
In addition to the general health benefits of eating a variety of foods, Wynn cites the example of cats dying from heart failure caused by a taurine deficiency in the years before we knew that taurine needed to be added to their food. “The cats whose owners were feeding one particular premium food had the worst problems,” Wynn says. “Rotating the diet might have helped prevent this problem.”
We are now learning that taurine is conditionally required by some dogs, and that certain diets, particularly lamb and rice, are low enough in taurine to cause a form of heart disease called dilated cardiomyopathy (DCM) in susceptible breeds. Once again, rotating between foods that use other protein and carbohydrate sources can prevent these problems from occurring.
Complete and Balanced Foods
Commercial dog foods are designed to be complete and balanced, meaning they meet the dietary guidelines developed by the Association of American Feed Control Officials (AAFCO). Nutritional content of foods can vary, however, based on how they’ve been stored, changes in ingredient sources and other factors.
Some foods contain only the bare minimum of required nutrients. If these degrade during storage or if an individual dog’s needs are greater than average due to health conditions or activity levels, deficiencies might develop over time.
Because dog food manufacturers use different combinations of vitamin and mineral supplements to meet AAFCO guidelines, different foods will be lower in some nutrients and higher in others. Rotating among various brands of food is one way to balance out the different nutrient compositions in different diets.
Rotating among ingredients, particularly protein sources, is another way to introduce variety to your dog's diet. Individual foods vary in the amount of amino acids, vitamins and minerals they contain. Routinely changing the protein and carbohydrate sources in the foods you use will provide a broader spectrum of nutrition.
Homemade Diets
If you feed a homemade diet, variety is even more important. Relying on a single recipe, even if it is designed to meet AAFCO guidelines, might produce deficiencies over time. It's better to rotate between two or three balanced recipes or to simply change the main ingredients in the recipe you're using. We simply can’t know the nutritional value of each individual ingredient with the accuracy these recipes often require.
Your ingredients might vary from those in the USDA database used to create the recipe depending on their source and how they are cooked, among other factors. Was the chicken breast in the recipe from broilers, fryers, roastin or stewing chickens? Is cooking in the microwave the equivalent of fried, raoasted, rotisseried or stewed chicken? Is your cup of carrots in large or small chunks, or grated?
People are advised to eat a wide variety of healthy foods to ensure adequate nutrition. Studies have shown that it's difficult to induce nutritional deficiencies in animals that are fed a wide variety of foods. When home preparing your dog's meals, it's safer to feed a variety of different foods in appropriate proportions than to always feed the exact same thing.
Food Allergies
In addition to the nutritional value of food rotation, dogs might be less prone to allergies from food if they aren't always fed the same food. Allergies tend to develop over time, so the longer a dog is exposed to the same ingredients, the more likely the dog will develop an allergy to one or more of those ingredients. By rotating among different protein and carbohydrate sources, food allergies might become less likely.
One warning: Try not to feed exotic proteins, such as duck, rabbit and venison to your dog. It’s best to reserve the unusual proteins for the future in case your dog develops food allergies and needs to eat an elimination diet using a novel protein (one they’ve never eaten before).
Adding Fresh Foods
Add nutrition and variety to your dog’s commercial diet by supplementing with fresh foods, including eggs, meat, liver, yogurt, cottage cheese, vegetables and canned fish with bones (such as jack mackerel, pink salmon and sardines).
“It's pure folly to assume that anyone, even companies with billions of dollars invested in research, can create a perfect diet for every animal,” Wynn says. “Some veterinarians now recommend supplementing a dog’s diet with meat and vegetables. This practice may provide the pet with phytochemicals and other vital nutrients that have yet to be discovered by nutritional science.” Don't add carbohydrates to dry foods, which are already high in carbs unless you add at least an equal amount of high-protein foods to the diet as well.
Fresh foods have more nutritional value than processed foods. As long as the foods you add are appropriate and don’t make up more than about one-quarter of your adult dog's total diet, you don’t need to worry about upsetting the nutritional balance. If you add more fresh food than that, or if you are feeding a puppy (particularly one under the age of 6 months), you must be careful about balancing the diet, including adding the right amount of calcium.
Digestive Upset
To avoid digestive problems, transition slowly to a new food. Replace about 25 percent of the old food with the new for the first few days, then increase the new food to half the diet for the next few days and so on, taking about two weeks to make the full transition. If your dog starts to develop loose stools, return to the previous food until stools are back to normal, then try again, waiting a week in between each increase.
Be careful about switching from a low-fat food to one that's much higher in fat – the sudden increase in fat can trigger pancreatitis (inflammation of the pancreas, a painful and potentially dangerous condition) in susceptible dogs. It's better to increase the amount of fat gradually by first transitioning to a food with moderate amounts of fat.
Digestive upset might also occur because changes in the amount of fat, protein and carbohydrates can cause shifts in the bacterial population in the gut. “Another way to get dogs through food transitions is to start feeding a probiotic a few days beforehand, continuing for a few days after the switch is completed,” says Dr. Wynn.
A few dogs might not be able to handle food rotation without experiencing serious digestive upset; i this case, it would be better to continue feeding the food the dog does well with, and perhaps add some fresh foods to the diet.
Transitioning slowly and adding probiotics become more important the longer a dog has been on the same food and the more prone it is to digestive upset. Dogs that are used to getting different foods rarely have any problem switching from one food to another.
Give it a try
Many people who think their dogs are doing well are surprised to see improvements after a diet change. Even if the diet you feed is high-quality, your dog might benefit from rotating among different brands or formulas – including different protein sources – and from the addition of fresh foods.
I regret that I no longer have much time to respond to questions. See my Contact page for more information. My name is Mary Straus and you can email me at either or