Cushing's disease can be difficult to treat. Dogs diagnosed with Cushing's have different nutritional needs than those without it. The good news is that dietary therapy can help control the symptoms associated with this disease. To understand the special dietary needs of a dog diagnosed with Cushing's Disease, it helps to know what causes Cushing's disease, which is excess cortisol.
Dietary Needs for Dogs With Cushing's Disease
It is very important that you don't feed a dog with Cushing's table scraps high in fat or sugar. Dogs with Cushing's disease require a diet with ratios of fat, protein, and carbohydrates different from that of a dog without this disease. The right diet can help to lower the cortisol levels in your dog's body and increase its life span.
Dogs with Cushing's do best on a diet based on a highly digestible protein. Protein helps to prevent muscle wasting, a common side effect of Cushing's disease. Some examples of highly digestible protein sources include egg whites, beef, chicken, lamb, salmon, and organ meats.
A low-fat diet is important because a dog with Cushing's is predisposed to hyperlipidemia (which means the dog's blood has abnormally elevated levels of cholesterol and triglycerides). The percentage of fat in your dog's diet should be less than 12 percent based on a dry matter basis (DM). The dry matter basis is the amount of protein, fat, and fiber in the food after taking out the moisture content of the food. It provides a more accurate way of comparing one food to another, because the moisture content of different foods is likely to vary widely, which alters the ratios of protein, fat, and fiber present.
Moderate levels of fiber are needed in a diet for a dog with Cushing's. Levels in the 8 to 17 percent range are considered appropriate. This is also based on a dry matter basis.
How to Calculate Dry Matter Basis
To determine the amount of fiber or fat on a dry matter basis, divide the reported amount of fiber or fat listed on the food label by the total amount of dry matter in the food. Then multiply that number by 100. Dry matter is 100 minus the percentage of moisture listed on the package. For example, say the percentage of moisture on your bag of food is listed as 10. The fiber percentage is 8, and the fat is 12.
Example Calculation No. 1:
- Subtract the percentage of moisture (10 percent in example No. 1) from 100 to determine the total amount of dry matter (the Dry Matter Basis):
100 - 10 = 90 percent Dry Matter Basis
- Divide the reported percentage of fiber (8 percent) by the Dry Matter Basis (90 percent), then multiply this figure by 100:
( 8 / 90 ) x 100 = 8.9 percent fiber
- Divide the Fat percentage (12) by the Dry Matter Basis (90 percent), then multiply by 100:
( 12 / 90 ) x 100 = 13.3 percent fat
Based on the guidelines, this food would not be appropriate for a dog with Cushing's because while the fiber content is within the 8 to 17 percent range, the fat content on a Dry Matter Basis exceeds the 12 percent limit for fats. Also, note that, after accounting for the amount of moisture in the dog food, the percentages of both fiber and fat increased. this may not seem like a large increase compared to the listed percentages, but if a food contains a greater amount of moisture, the percentages of fiber and fat will increase once you account for the amount of moisture present in the food. for example, consider a food with a listed moisture content of 30 percent, also made with 8 percent fiber and 12 percent fat.
Example Calculation No. 2:
- Subtract the percentage of moisture (30 percent in example No. 2) from 100 to determine the total amount of dry matter (the Dry Matter Basis):
100 - 30 = 70 percent Dry Matter Basis
- Divide the reported percentage of fiber (8 percent) by the Dry Matter Basis (70 percent), then multiply this figure by 100:
( 8 / 70 ) x 100 = 11.4 percent fiber
- Divide the Fat percentage (12) by the Dry Matter Basis (70 percent), then multiply by 100:
( 12 / 70 ) x 100 = 17.1 percent fat
This is why figuring out the Dry Matter Basis is so important when planning a diet for a dog with Cushing's disease. The difference between the fat content in example No. 1 and example No. 2 is nearly 4 percent. Furthermore, the food in example No. 2 contains too much fat, well above the 12 percent limit for fat in a diet fed to a dog with Cushing's disease.
Commercial Diets for Dogs With Cushing's Disease
There are many high-quality commercial dog foods on the market. Following the recommendations above can be helpful when reading dog food labels. Consult your veterinarian prior to choosing a diet. Some veterinarians use prescription diets such as royal canine gastrointestinal low-fat, or Hills Prescription Diet Metabolic, to manage Cushing's disease.
Homemade Diets for Dogs With Cushing's
Many pet owners have had success controlling their dog's Cushing's disease through a homemade diet. Companies such as JustFoodForDogs will make a homemade diet and ship it to you. The advantage of using JustFoodForDogs is the company's ability to guarantee all the nutritional requirements are met. It can also adjust recipes according to your dog's specific needs.
Go with a Balanced Diet
If you choose to make a home-cooked or even a raw diet, consult with a veterinary nutritionist to make sure you are feeding a balanced diet. Tufts University has board-certified veterinary nutritionists who provide phone consultations with you regarding your dog's diet. Tufts can even formulate a unique diet for your dog.
Can Dietary and Nutritional Therapy Cure Cushing's?
Treatment for Cushing's can be complicated. Cushing's is a disease that is controlled and managed, rather than cured. The good news is that diet and nutrition have proven to be one of the most important factors in extending the life span of dogs with Cushing's. Food therapy can control high cortisol levels, improve the immune system, and increase energy levels. A combination of medicine prescribed by your veterinarian and a high-quality commercial or homemade diet can help dogs with Cushing's live a quality life for years after their diagnosis.