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Diet for Animals with Kidney Disease
March 21, 2013
Diet for Animals with Kidney Disease
To Protein, or Not to Protein? That is the Question
What is a high quality protein?
High quality proteins are ones that closely match the proper mix of amino acids the body needs. Ideally, there would be exactly the right number of every amino acid and no excess of protein material, making both the liver and the kidneys happy. In general, animal source proteins, such as meat, milk and eggs are higher quality than plant source proteins. This is because the animal that produced these items already made the proper proteins and so they are already in the proper mix. That is why cottage cheese is considered to be a higher quality protein source than soy, for instance. Note that some amino acids, such as taurine, are sensitive to heat, which is one of the reasons why raw meat is considered higher quality than cooked meat.
When developing a diet for your pet with kidney failure, the goal is to reduce phosphorus by feeding moderate to high fat, moderate amounts of high quality protein,and low phosphorus carbohydrates to provide calories.
Dogs & cats with kidney problems often do better when fed several small meals throughout the day rather than just one or two large meals.
Feeding a low phosphorus diet has been shown to slow progression of kidney disease. NRC guidelines are to feed no more than 22.25 mg/kg phosphorus daily (about 10 mg per pound of body weight) for a dog with advanced kidney failure. For dogs in early stages, recommended phosphorus amounts can be as high as 60 mg/kg (or 30 mg/lb). Anywhere from 15-40 mg/kg (7 - 18 mg/lb) is considered a low phosphorus diet. In general, foods highest in phosphorus include bones, dairy products, fish (with bones), organ meats, and egg yolks. That does not mean not to feed these foods at all, as they are an important component of a healthy diet, but they should be fed in moderation. Be wary also of the amount of phosphorus in grains and vegetables that you feed. Examples of the amount of phosphorus you should be feeding daily, based on the range of 15-40 mg/kg, and 60 mg/kg for very early stages (the further advanced the kidney disease is, the less phosphorus you should be feeding):
- 10 pound dog: 68 - 182 mg (up to 272 mg in very early stages)
- 25 pound dog: 170 - 455 mg (up to 682 mg in very early stages)
- 50 pound dog: 340 - 900 mg (up to 1364 mg in very early stages)
- 75 pound dog: 511 - 1364 mg (up to 2045 in very early stages)
- 100 pound dog: 680 - 1818 mg (up to 2727 in very early stages)
Moderate to High Fat
Fat provides low-phosphorus calories, and so can be used to increase caloric intake without increasing phosphorus. With rare exception, dogs do not suffer from high cholesterol or other human problems associated with high fat intake. However, too much fat can be problematic for some dogs, and renal disease can predispose dogs to pancreatitis (or it's possible that the combination of low protein and high fat found in prescription diets may be the underlying cause, as this combination is known to predispose a dog to pancreatitis).
If your dog is overweight or relatively inactive, and doesn't need a lot of calories, then feed moderate amounts of fat. If your dog is quite active and needs a lot of calories, then you can increase the amount of fat to provide more calories without increasing phosphorus. Too much fat may lead to diarrhea or mucousy stools, and dogs that are prone to pancreatitis cannot handle too much fat. If fat is reduced, carbohydrates will have to be increased to provide low-phosphorus calories.
It is important to increase the amount of fat you feed gradually, to avoid digestive upset and to try to avoid the possibility of pancreatitis. If you see signs of problems, such as your dog seeming uncomfortable after meals, loose stools, loss of appetite, vomiting or diarrhea, that is a sign to decrease the amount of fat in the diet right away to a level your dog can tolerate.
Dietary sources of fat include:
- Fatty Meats -- use the highest fat hamburger you can get. Lamb is especially high in fat. Pork is also high fat. Dark meat chicken and turkey has more fat than white meat, although poultry is still a low fat meat, so it's best to include the skin if you feed chicken or turkey. Beef has less phosphorus than chicken. Lamb and turkey are in between.
- Use whole milk yogurt, cottage cheese, ricotta cheese, etc. -- since these foods are high in phosphorus, they should be fed in moderation, but use the kind with the most fat when they are fed. Try goat's milk yogurt for flavor if your dog doesn't like the regular kind.
- Egg Yolks are high in fat, but also very high in phosphorus, so should be fed in moderation.
- Fat can also be added in the form chicken fat, coconut oil, & fish oils Be very careful about adding pure fat to the diet -- start with very small amounts and stop immediately if you see signs of problems.
- In general, vegetable oils are not recommended as a source of fat. They are high in omega-6 essential fatty acids, which are inflammatory, and are not a good source of nutrition for dogs. Omega-6 fatty acids have been found to be harmful to dogs with kidney disease. Instead of vegetables oils, use Fish Oil, such as Salmon. While Flax seed oil has more omega-3 fatty acids than most plant oils, it is also high in omega-6 and so is not recommended. Olive oil is probably OK to use in small amounts, as it is mostly omega-9, which as far as I know does not affect kidney function.
Again, be cautious when adding fat to the diet. Increase amounts gradually, and back off if you see any signs of your dog having problems with the higher amounts.
How much protein to feed is still a matter of some debate, although it is not necessary to feed a low protein diet unless your dog is uremic. Protein may need to be moderately reduced for dogs with glomerulonephritis, to reduce protein loss in the urine which contributes to inflammation.
Recommendations for dogs with mild to moderate CRF (creatinine 1.6-4.5 mg/dL, or 141-398 µmol/L) are 2.0 - 2.2 g/kg body weight of high biologic value protein, or around 1 gram of protein per pound of body weight daily. This is higher than the recommendations for normal, healthy dogs. Note the grams of protein refers to a nutritional analysis, not grams of meat.
As long as the amount of phosphorus is kept within desirable limits, and your dog is not uremic and does not have excessive proteinuria, you really don't have to worry much about feeding too much protein (you may need to be careful not to feed too little). It is important to feed high quality protein. Eggs have the highest quality protein, but egg yolks are very high in phosphorus. Egg whites can be added to low-protein diets to provide additional protein with very little phosphorus, although the protein in egg whites is not complete. Raw or lightly cooked meat is another high quality source of protein. Green Tripe is an excellent food for dogs with kidney disease.
Carbohydrates & Fibers
Dogs & Cats have no nutritional need for carbohydrates, but in order to reduce phosphorus, you will probably need to feed around 50% carbohydrates (more if the diet is also lower in fat). In general, the goal is to add calories without adding much phosphorus. For this reason, grains like Farina, pasta, and vegetables like sweet potatoes and winter squashes are good choices. Phosphorus amounts given below in parentheses and are shown in mg per 100 grams. If a range of numbers is given, the lower number is for cooked, the higher number is for raw. If only one number is given, it is for raw.
- Vegetables must be either cooked or pureed in a juicer, food processor or blender in order to be digestible by dogs. Cooking leaches out phosphorus (as well as potassium and magnesium), so it may be the better way to feed for dogs in kidney disease, although cooking also leaches out or destroys vitamins. Boiling or steaming removes more phosphorus than baking, as long as you don't also give the water the food was cooked in. Note that celery, parsley and dandelion greens are diuretics, which may not be desirable for dogs with kidney disease. Dogs with arthritis should avoid white potatoes, tomatoes, eggplant and peppers. Cabbage is good for ulcers, which are common with kidney disease. Potatoes, sweet potatoes and yams are good choices. Other vegetables, with phosphorus amounts (mg/100 grams) in parentheses, include: asparagus (56), beets (40), broccoli (66), carrots (44), cauliflower (44), celery (25), collard greens (10), dandelion greens (66), endive (28), green beans (19-38), green peppers (19), kale (56), parsley (58), parsnip (71), peas (77-117), pumpkin (44), red cabbage (42), romaine lettuce (45), acorn squash (27), butternut squash (27), crookneck squash(32), spaghetti squash (14), tomato (24), watercress (60), zucchini (32).
- Fruits: You can also feed fruits, including apple (7), banana (20), cantaloupe (17), cranberries (9), cucumber (20), mango (11), peach (12), pear (11), pineapple (7).
- Fruit does not have to be cooked or pureed in order to be digestible. Colored fruits, such as papaya and mango, are especially good for dogs with arthritis. Bananas and pumpkin are high in potassium. Avoid grapes and raisins, which have been linked to kidney failure when fed in large amounts to a few dogs. Too much fruit may lead to loose stools.
- Grains: If you do feed grains, stick to those that are lowest in phosphorus In general, white rice is lower in phosphorus than brown rice. Farina (Cream of Wheat Cereal), Cream of Rice Cereal, Malt-O-Meal, and Tapioca are low phosphorus alternatives that can also be used. Try adding butter, meat juices or meat fat for flavor and calories, and cooking in broth or gravy rather than water for added flavor (use low or no sodium broth).
- Pasta: Pasta with butter added is a good choice for tasty, low-phosphorus calories.
- Honey: Raw honey is good for dogs in general and can be fed to dogs with kidney problems as well. Phosphorus amount is negligible.
Sodium, actually not an issue
Pets with kidney disease may also have hypertension (high blood pressure), and the standard recommendation is to feed a reduced-sodium diet. However, it is questionable whether this is necessary as there is NO proof in dogs or cats , and a low-sodium diet may even be harmful.
Most other dietary restrictions depend on your individual dog. If your dog has high potassium, you will need to limit the amount of potassium you feed, for example (bananas, pumpkin, potatoes, sweet potatoes, pears, sardines, kiwi, beets, yogurt, winter squash, banana, carrots, celery, broccoli. are high in potassium) -- keep in mind that high potassium is unusual in dogs with kidney disease and may indicate Addison's Disease instead.
Conversely, and more commonly, if your dog of cat’s potassium levels are too low, you will need to give potassium rich foods or potassium salts (both can occur with kidney disease, but it is my understanding that low potassium is more common, and high potassium is only likely to occur when kidney disease is very advanced).
Raw Meaty Bones
Bones are high in phosphorus and other minerals that can be hard on kidney patients. When you reduce or eliminate the amount of bone in the diet, you should add 1/2 teaspoon ground eggshell (or 1,000 mg plain calcium from other sources) per pound of meat fed to balance out the calcium/phosphorus ratio. If your pet's calcium values are too high, you may need to use aluminum based phosphorus binders instead
Dogs & Cats with kidney disease should always have access to water, even if it causes accidents in the house. Distilled water may be best to use, or maybe purified water, such as with a faucet filter. Well water may be very high in minerals and is best avoided, use bottled water instead, or find a filter that will remove excess minerals. If you use a water softener at your house, your water will be high in sodium, which is not a good idea if your dog has high blood pressure. Again, switch to bottled water (filters do not remove sodium from water). It is important that the animal stay hydrated, as dehydration is very harmful to the kidneys. Adding water to the food, particularly if you must feed dry food, helps with this.
The most important supplement to give to pets with kidney disease omega-3 fatty acids which have been found to slow progression of kidney disease. Give an amount that provides as much as 300 mg EPA and DHA combined per 10 pounds of body weight daily, preferably split into two doses.
Herbs: the following herbs are to increase blood circulation, decrease inflammation & increase urine output