Diet and Urinary Tract Stone and

Diet and Urinary Tract Stone and Idiopathic Lower Urinary Tract Disease

Urinary calculi are common with one to three percent of all dogs and cats suffering at some time. The most important cause in cats is dietary. Diet is a common cause in dogs but urinary tract infection is an important cause of some stones. Urinary calculi are more common in animals fed commercial pet foods. Some urinary calculi grow to sizes that they remain in the bladder. Urinary calculi can also be small enough to pass into the urethra and some can lodge there and obstruct urination. Urinary calculi cause signs of stranguria, frequent urination, urinary incontinence, and hematuria. Urinary calculi can remain in the bladder for months before signs of a problem are recognized. Cystic calculi can often be identified on abdominal palpation. Radiographs reveals most calculi; urate stones are radiolucent and are not revealed. Calculi the size of sand are not apparent on radiographs but they can readily obstruct the urethra. Urinalysis can assist in evaluating for urinary tract calculi. Urinalysis cannot prove the presence of calculi but it can reveal urinary tract infection and conditions conducive to calculi formation such as alkaline urine and crystal formation. Other tests are usually not necessary to evaluate for calculi.

Types of Urinary Tract Calculi^1,2

Struvite calculi containing magnesium, phosphate, and ammonia or hydrogen are the most common found in cats, representing 65 to 70 percent of all calculi. Calcium oxalate calculi are the second most common in cats at 20 percent of the total. The third most common calculi are urates and calcium phosphate compose the remainder. Dogs are similar in that struvite calculi are most common. Calcium oxalate calculi are next in frequency followed by cystine and urate calculi. Cystine calculi appear in some dogs with a genetic defect causing urinary excretion of excess cystine. Urate stones are common in dogs with a genetic difference (Dalmations) that causes purines to be metabolized to uric acid. In these dogs urinary excretion of uric acid often results in calculi formation. Dietary management is the most important treatment for nearly all of these urinary calculi. Struvite calculi in dogs are the exception where antibiotic treatment for urinary tract infection is more important. Most cats and dogs with urinary calculi benefit from management to increase water consumption.

Types of Urinary Tract Calculi^1,2

In cats struvite calculi containing magnesium, phosphate, and ammonia or hydrogen are most common, representing 65 to 70 percent of all calculi. Calcium oxalate calculi are the second most common at 20 percent. The third most common calculi are urates, and calcium phosphate compose the remainder.

Dogs are similar in that struvite calculi are most common. Calcium oxalate calculi are next in frequency followed by cystine and urate calculi. Cystine calculi appear in some dogs with a genetic defect causing urinary excretion of excess cystine. Urate stones are common in dogs with a genetic difference (Dalmations) that causes purines to be metabolized to uric acid. In these dogs urinary excretion of uric acid often results in calculi formation.

Pathogenesis of Struvite Calculi^1,2

Diet-Altered Acid Base Balance and Disease
Acid-base alterations contribute importantly to the formation of urinary tract calculi. Some calculi result from urinary tract infection but the diet is important for their formation in many dogs. Diet is the most important factor for calculi formation in cats. Until recently, the compositions of commercial cat foods favored the formation of calculi. Most cat foods have been modified to reduce the risk of calculi formation.

Urinary Tract Stones and Urolithiasis in Cats^1,2

The incidence of urinary tract calculi formation in feline urologic syndrome gradually increased during the past three decades. During that time cats were confined more and greater numbers were fed commercial cat foods. When cats hunted for food or fed owner-prepared foods, feline urologic syndrome was uncommon.

Urinary tract infection plays no role in struvite calculi formation in cats although it is the important cause in dogs. In the past, suggested causes included infection, both bacterial and viral; early castration of males; endocrine imbalance; high dietary ash, magnesium, phosphate and nitrogen; low water intake; obesity; dry cat foods; and stricter confinement of cats causing less frequent urination.

Feline urologic syndrome is very uncommon in cats fed as carnivores. Dry commercial cats foods contain primarily vegetable material, however. Grain and soy products are the most abundant ingredients. These foods also contain mineral mixtures that often include calcium carbonate (promotes alkaline conditions) or bone (high magnesium). Without special precautions a cat food based on these ingredients produces neutral or alkaline urine, a factor that contributes to feline urologic syndrome. The primary cause of feline urologic syndrome is now known to be the formation of neutral or alkaline urine in an animal that evolved to produce acidic urine. Carnivores consuming a high protein meat diet produce acid urine. Cat foods require mineral compositions appropriate for producing acid urine. Animals consuming high-protein diets produce acid urine.

Some dietary minerals such as calcium chloride and ammonium chloride promote acid formation. Some dietary minerals containing sodium, potassium, magnesium, or even calcium produce alkaline conditions. Any chemical that readily decomposes to carbon dioxide and water generally causes body fluids to become more alkaline. After the carbon dioxide is excreted, the rest of the chemical remains and promotes the alkalinity.

Calculi Formation³Many metabolic factors appear to be important in the formation of struvite calculi. Urinary concentrations of magnesium, ammonia, and phosphate are important, with calculi formation more likely with an increase in their concentrations. Any struvite formed remains in solution in acid urine. Struvite crystallizes to form insoluble calculi in alkaline or neutral urine. It has been believed that the magnesium content of diets should be important in preventing calculi. Under dietary conditions that produce a neutral urine pH, the major dietary factor that contributes to a high incidence of calculi is high magnesium. Under these same conditions producing a urine pH that is neutral, there are small effects on calculi formation from 1) variation in water intake and salt intake, 2) frequency of urination and 3) dietary levels of calcium, phosphate, and other minerals. Some of these factors plus others such as infection and level of ash can affect urine pH, however. Decreasing the pH of urine not only prevents calculi formation but also dissolves calculi that have already formed.

In summary, struvite stone formation is associated with feeding diets that result in neutral to alkaline urine and not primarily because the diet is high in magnesium. Since the cat evolved as a desert animal, it efficiently conserves water and produces a concentrated urine. Concentrations are high for magnesium, ammonium and phosphate that become supersaturated and form crystals at neutral and alkaline pH; the formation of struvite crystals and stones follows. At acid pH (below pH 6.6), struvite remains largely in solution, despite a high mineral content.

Feeding to Prevent Urinary Stones³Diets for cats should have a composition that will produce an acid urine (pH should be 6.2 to 6.6) in cats fed free-choice. Diet directly affects urine pH for a number of hours after eating (see figure).⁴ A diet producing urine in the desired pH range should not result in a urine pH greater than 7.0 during any time 4 to 6 hours after feeding. The diet should not have the potential of reducing the pH too much, however, because that can lead to demineralization of bones resulting in osteoporosis. Urine pH of carnivores eating natural prey is between 6.2 and 6.6, so this pH should be safe, even for long-term feeding.

A diet that produces urine pH greater than 7.0 in an adult cat produces much lower pH in a growing kitten. The urine pH during bone growth can be less than 6.0 until the animal is over a year old. That low pH has no harmful effects during the cat's growth. If the diet continues to produce a low urine pH after growth stops, demineralization of bone will occur, leading to osteoporosis. The low urine pH in growing cats explains why struvite stone formation is rare until the animal is older than one year old; it is most common at three to four years of age.

Dietary Management of Struvite Calculi in Cats³

Cats with struvite calculi must be fed a diet that increases urine pH little. Alkaline urine increases the risk for struvite calculi formation. Different diets and feeding frequency have effects on urine pH in a 24 hour period.

Dietary magnesium has been thought to contribute to struvite calculi formation. That prompted manufacturers to reduce magnesium levels in cat foods. High dietary magnesium does not promote calculi formation, however. Magnesium is necessary for the normal urinary calcium excretion. Reducing dietary magnesium can reduce calcium excretion and promote formation of calcium oxalate calculi. Humans with recurring oxalate stone formation have fewer recurrences when magnesium intake is increased. The following diets for cats have higher than usual magnesium concentrations. They do not contain the smaller amounts found in many commercial cat foods.

Since phosphate combines with magnesium to form struvite crystals, it is possible that controlling dietary phosphate might reduce calculi formation. Feeding recommended phosphate levels to normal cats does not affect calculi formation, however. Phosphate causes if anything urine pH to become more acid, which reduces calculi formation. Commercial cat foods have acidifying agents added such as phosphoric acid salts. This is comparable to medicating cats with acidifiers which should not be recommended, however. "No specific dosage of acidifier can be considered safe and effective under all conditions."³ Consequently natural sources of phosphate should be fed to acidify urine. Brewers yeast is an important source of phosphate in the following cat diets. Manufacturers produce low ash cat foods so less ash must be excreted in urine. Ash consists of minerals remaining after a food’s incineration. High ash diets do not contribute to stone formation, however.

The following diets contain nutrients that reduce urine pH and recommended levels of magnesium, phosphate, and ash for normal cats. For cats with struvite calculi the recommended dietary level for magnesium is 20 to 40 mg/100 kcal and for phosphorus is 125 to 250 mg/100 kcal. These are both higher than NRC recommendations for growing or adult cats. The levels of these two minerals increase with removal of dietary oil (where oil is included) and rice, something that reduces caloric content approximately 150 kcalories. Dietary calcium levels follow NRC recommendations. Diets with higher sodium, formulated with sardine, tuna or salmon, will increase water consumption.

Tofu and Sardines Diet

3 1/3 ounces tofu, raw firm (100 grams)
2 1/4 ounces sardines, canned, tomato sauce (71 grams)
1/2 egg yolk, chicken, cooked (8 grams)
1/2 ounce clams, chopped in juice (14 grams)
1/3 cup brown rice, long-grain, cooked (65 grams)
1/2 ounce brewers yeast (14 grams)
2 teaspoon vegetable (canola) oil (10 grams)
1/4- teaspoon bone meal powder (1 grams)
1/5 multiple vitamin-mineral tablet (made for adult humans)

provides 501 kcalories, 37.4 g protein, 29.6 g fat
see tables for a cat's or kitten's caloric needs
provides 62.2 mg sodium/100 Kcalorie diet―a high sodium intake

3 1/3 ounces tofu, raw firm (100 grams)
2 2/3 ounces (weight before cooking) chicken (boneless breast) (76 grams)
1/2 egg yolk, chicken, cooked (8 grams)
1/2 ounce clams, chopped in juice (14 grams)
1/3 cup rice, long-grain, cooked (65 grams)
1/2 ounce brewers yeast (14 grams)
2 teaspoon vegetable (canola) oil (10 grams)
1/4 teaspoon bone meal powder (2 grams)
1/5 multiple vitamin-mineral tablet (made for adult humans)

provides 469 kcalories, 42.6 g protein, 23.6 g fat
see tables for a cat's or kitten's caloric needs
provides 18.3 mg sodium/100 Kcalorie diet―a low sodium intake

Tofu and Beef Diet

3 1/3 ounces tofu, raw firm (100 grams)
4 ounces (weight before cooking) beef (lean ground) (114 grams)
1/2 egg yolk, chicken, cooked (8 grams)
1/2 ounce clams, chopped in juice (14 grams)
1/3 cup rice, long-grain, cooked (65 grams)
1/2 ounce brewers yeast (14 grams)
1/4- teaspoon bone meal powder (1 grams)
1/5 multiple vitamin-mineral tablet (made for adult humans)

provides 494 kcalories, 46.7 g protein, 24.1 g fat
see tables for a cat's or kitten's caloric needs
provides 20.2 mg sodium/100 Kcalorie diet―a low sodium intake

Tofu and Lamb Diet

3 1/3 ounces tofu, raw firm (100 grams)
4 ounces (weight before cooking) lamb (lean ground) (114grams)
1/2 egg yolk, chicken, cooked (8 grams)
1/2 ounce clams, chopped in juice (14 grams)
1/3 cup rice, long-grain, cooked (65 grams)
1/2 ounce brewers yeast (14 grams)
1/4 teaspoon bone meal powder (2 grams)
1/5 multiple vitamin-mineral tablet (made for adult humans)

provides 522 kcalories, 46.5 g protein, 27.4 g fat
see tables for a cat's or kitten's caloric needs
provides 16.2 mg sodium/100 Kcalorie diet―a low sodium intake

Tofu and Clams Diet

3/4 cup tofu, raw firm (100 grams)
1/2 egg yolk, chicken, cooked (8 grams)
1 ounce clams, chopped in juice (28 grams)
1/3 cup brown rice, long-grain, cooked (65 grams)
1/2 ounce brewers yeast (14 grams)
1 teaspoon vegetable (canola) oil (5 grams)
1/4- teaspoon bone meal powder (1 grams)
1/5 multiple vitamin-mineral tablet (made for adult humans)
provides 548 kcalories, 45.5 g protein, 25.5 g fat
see tables for a cat's or kitten's caloric needs
provides 13.8 mg sodium/100 Kcalorie diet―a low sodium intake

If rice is eliminated from any of these diets, the caloric content will be 68 calories less and the protein content will be about 1 gram less. Without rice in beef or lamb diets, bone meal is reduced.

Dietary Management of Struvite Calculi in Dogs³

Dogs develop struvite calculi because urine is alkaline and is saturated with magnesium and phosphate. Dogs must have a urinary tract infection for struvite calculi formation. Sometimes bacteria cannot be cultured from urine or struvite calculi. Infection is still necessary for most struvite calculi formations. Infection responsible for calculi formation may have been eliminated by antibiotics. Also infection can be present where it is not possible to culture and find bacteria. Some dogs produce alkaline urine despite diets or drugs to acidify urine. These dogs also can develop struvite calculi without infection.

Diets containing reduced amounts of high-quality proteins, phosphorus, and magnesium reduce urea, phosphate, and magnesium in urine. Studies show these diets promote struvite stones dissolution in dogs. All dogs in these studies also received antibiotics for urinary tract infection, however. Pet food manufacturers producing diets with low protein, magnesium, and phosphorus claim the diets are responsible for calculi dissolution. Antibiotic treatment is far more important, however. If antibiotics are not given calculi remain. If a dog with calculi receives antibiotics and no special diet the calculi dissolve and disappear. Thus, the diet is not critical for managing dogs with struvite calculi.

The following diets contain proper amounts of nutrients for meeting dogs’ needs. The diets contain near normal levels of nutrients such as magnesium because reduction of this mineral can increase risk for calcium oxalate stones. Sodium chloride can be increased to promote a greater intake of water.

Cottage Cheese and Rice Diet

2/3 cups cottage cheese, 2% fat (151 grams)
1 egg, large, chicken, whole, cooked
2 cups brown rice, long-grain, cooked (390 grams)
2 teaspoons vegetable (canola) oil (10 grams)
1/2 ounce brewers yeast (14 grams)
1/2 teaspoon bone meal powder (3 grams)
1/4 teaspoon nosalt (salt substitute-potassium chloride)
1/5 multiple vitamin-mineral tablet (made for adult humans)

provides 777 kcalories, 42.6 g protein, 22 g fat
supports caloric needs of a 25 pound dog
provides 92 mg sodium/100 Kcalorie diet―a high sodium intake

Beef and Rice Diet

1/4 pound (weight before cooking) very lean beef (114 grams)
1 egg, large, chicken, whole, cooked
2 cups brown rice, long-grain, cooked (390 grams)
1/2 ounce brewers yeast (14 grams)
1/2 teaspoon bone meal powder (3 grams)
1/4 teaspoon nosalt (salt substitute-potassium chloride)
1/5 multiple vitamin-mineral tablet (made for adult humans)

provides 745 kcalories, 41.3 g protein, 21.2 g fat
supports caloric needs of a 24 pound dog
provides 21.8 mg sodium/100 Kcalorie diet―a low sodium intake

Tuna and Rice Diet

4 ounces tuna, canned in water, without added salt (114grams)
1 egg, large, chicken, whole, cooked
2 cups brown rice, long-grain, cooked (390 grams)
2 teaspoons vegetable (canola) oil (10 grams)
1/2 ounce brewers yeast (14 grams)
1/2 teaspoon bone meal powder (3 grams)
1/4 teaspoon nosalt (salt substitute-potassium chloride)
1/5 multiple vitamin-mineral tablet (made for adult humans)

provides 911 kcalories, 48.8 g protein, 38.1 g fat
supports caloric needs of a 31 pound dog
provides 92.7 mg sodium/100 Kcalorie diet―a low sodium intake

(With no addition of 2 teaspoons vegetable oil the caloric content is 821 kcalories and fat content is 24 g. The oil can be omitted from the diet if the plan is to reduce fat intake.)

Dietary Management of Calcium Oxalate Calculi in Cats and Dogs^5,6

Calcium oxalate calculi develop because urine is saturated with calcium and oxalate. Oxalate is a carbohydrate found in many foods and which can be produced from carbohydrate-like chemicals in foods. Inhibitors of oxalate calculi formation include phosphorus, magnesium, and citrate. Oxalate stones form more readily in acid urine. Urine with low pH and high calcium concentration does not produce calcium oxalate calculi when urine magnesium is normal or increased. Thus, dietary magnesium is important for preventing calcium oxalate calculi formation. Most pets are fed commercial pet foods before they form calcium oxalate calculi. After surgical removal of these calculi about 50 percent recur within 3 years. Thus, a different diet must be fed to prevent recurrence.

The following diets contain low oxalate and minimum calcium. They also contain normal phosphorus, which prevents absorption of excess calcium. The diet should contain no more than minimum vitamin D to minimize absorption of dietary calcium. Diets for cats must promote acid urine but that may be less important for dogs. Most important the following diets provide enough magnesium to minimize calculi formation. Magnesium should be 20 to 40 mg/100 kcalories of diet. High dietary sodium increases urine calcium, prompting some to recommend reducing dietary salt. It is unknown whether this promotes calculi formation, however. Anything increasing water consumption reduces stone recurrence. Current recommendations are to feed a vegetarian-type high fiber diet that is low in oxalate, calcium and vitamin D. The pet should also not be given excess amounts of substances, such as vitamin C, that can be converted to oxalate.

Diets for Adult Dogs with Oxalate Stones

Black-Eyed Peas and Rice Diet

2/3 cup blackeye peas, boiled (114 grams)
2 cups brown rice, long-grain, cooked (390 grams)
1 tablespoon vegetable (canola) oil (14 grams)
1/4 teaspoon bone meal powder (1.5 grams)
1/4 teaspoon nosalt (salt substitute-potassium chloride)
1/5 multiple vitamin-mineral tablet (made for adult humans)
season with table salt

provides 696 kcalories, 19.3 g protein, 17.8 g fat
supports caloric needs of a 21 to 22 pound dog
provides phosphorus 102 percent, calcium 55 percent,
sodium 33 percent, vitamin D at 63 percent of a dog's daily needs.

Black-Eyed Peas and Potato Diet

1 cup blackeye peas, boiled (171 grams)
2 cups potato, cooked with skin (246 grams)
1 tablespoon vegetable (canola) oil (14 grams)
1/4 teaspoon bone meal powder (1.5 grams)
1/5 multiple vitamin-mineral tablet (made for adult humans)
season with table salt

provides 598 kcalories, 19.4 g protein, 14.6 g fat
supports caloric needs of a 17 to 18 pound dog
provides phosphorus 98 percent, calcium 61 percent,
sodium 34 percent, vitamin D at 70 percent of a dog's daily needs.

Diets for Adult Cats with Oxalate Stones

Tuna Diet

4 ounces tuna, canned in water, without added salt (114 grams)
1/2 egg yolk, chicken, cooked (8 grams)
bone meal powder (0.3 grams)
1/5 multiple vitamin-mineral tablet (made for adult humans)

provides 273 kcalories, 26.6 g protein, 18.6 g fat
see tables for a cat's caloric needs
provides phosphorus 97 percent, calcium 31 percent,
sodium is high, vitamin D at 193 percent of a cat's daily needs.

Tuna and Rice Diet

4 ounces tuna, canned in water, dietetic (114 grams)
1/2 egg yolk, chicken, cooked (8 grams)
1/3 cup rice, long-grain, cooked (53 grams)
1 tablespoon vegetable (canola) oil (14 grams)
1/4- teaspoon bone meal powder (0.5 grams)
1/5 multiple vitamin-mineral tablet (made for adult humans)

provides 342 kcalories, 28 g protein, 18.8 g fat
see tables for a cat's caloric needs
provides phosphorus 97 percent, calcium 31 percent,
sodium is high, vitamin D meets cat's daily needs.

Salmon and Rice Diet

4 1/3 ounces salmon, canned with bone, low salt (123 grams)
1/2 egg yolk, chicken, cooked (8 grams)
1/2 ounce clams, chopped in juice (14 grams)
1/3 cup rice, long-grain, cooked (53 grams)
2 teaspoons vegetable (canola) oil (10 grams)
1/5 multiple vitamin-mineral tablet (made for adult humans)

provides 399 kcalories, 31.7 g protein, 22.2 g fat
see tables for a cat's caloric needs
provides calcium 66%, phosphorus 140%,
sodium is high, vitamin D meets cat's daily requirements

Dietary Management of Urate Calculi in Cats and Dogs

Urate and uric acid calculi form because ammonium urate and uric acid crystallize in urine. Urates and uric acid are produced by degradation of purine nucleotides involved in cell division and protein manufacture. Normally the liver degrades these substances to compounds that the kidneys readily excrete. In Dalmations, the liver converts only 30 to 40 percent of urates to the excretable form. This leaves considerable uric acid to be excreted. Many Dalmations show no clinical problems but some form urinary crystals and calculi from high urine uric acid levels. Some non-Dalmations do not degrade urates to the readily excretable form because liver disease compromizes this function. Some of these animals form urate calculi. A predictable number of Dalmations develop urate calculi and many are treated with drugs. Allopurinol is routinely used to reduce formation of urates from purines. This drug must be given daily and it can have side-effects. Fifty years ago when drugs were not available to prevent urate calculi, low-purine diets were fed. Faithful feeding of these diets prevented calculi formation. On feeding purine-containing foods urate stones recurred, however. The following diets are low in purines and are preferred to drugs for managing urate calculi disease.

Dogs with liver disease and urate calculi may require diets with lower protein in addition to low purines. These dogs often have elevated blood and urine ammonia because the liver cannot efficiently convert ammonia to urea. Although it may be necessary to feed a low-protein diet, dogs with liver disease often have a need for normal amounts of protein. Reducing dietary protein can cause complications reflecting protein deficiency. For example, low dietary protein can cause hypoproteinemia.

These diets are more effective in preventing calculi recurrence if they promote greater water consumption. Urate crystals do not form in dilute urine as they do in concentrated urine. Urate calculi are also more soluble in alkaline than acid urine. The following diets produce an alkaline ash and urine.

It is necessary to add taurine to the diet for cats with urate stones. Foods rich in taurine also contain high amounts of purines; they cannot be used.

Diets for Adult Dogs with Urate Calculi

Cottage Cheese and Potato Diet

2/3 cups cottage cheese, 2% fat (151 grams)
2 cups potato, cooked with skin (320 grams)
1 tablespoon vegetable (canola) oil (14 grams)
1/2 calcium carbonate tablet (200mg calcium)
1/4 teaspoon bone meal powder (1.5 grams)
1/5 multiple vitamin-mineral tablet (made for adult humans)

provides 523 kcalories, 26.5 g protein, 17.4 g fat
supports caloric needs of a 14 to 15 pound dog

Cottage Cheese and Potato Diet

2/3 cups cottage cheese, 2% fat (151 grams)
2 cups rice, long-grain, cooked (320 grams)
1 tablespoon vegetable (canola) oil (14 grams)
1/3 teaspoon bone meal powder (2 grams)
1/4 teaspoon nosalt (salt substitute-potassium chloride)
1/5 multiple vitamin-mineral tablet (made for adult humans)

provides 672 kcalories, 29.2 g protein, 18 g fat
supports caloric needs of a 20 to 21 pound dog

2/3 cups cottage cheese, 2% fat (151 grams)
1 cups potato, cooked with skin (123 grams)
1 tablespoon vegetable (canola) oil (14 grams)
1/4 teaspoon bone meal powder (1.5 grams)
1/5 multiple vitamin-mineral tablet (made for adult humans)
50 mg taurine

provides 397 kcalories, 23.7 g protein, 17.3 g fat
see tables for a cat's caloric needs

2/3 cups cottage cheese, 2% fat (151 grams)
3/4 cups rice, long-grain, cooked (120 grams)
1 tablespoon vegetable (canola) oil (14 grams)
1/4 teaspoon bone meal powder (1.5 grams)
1/4 teaspoon nosalt (salt substitute-potassium chloride)
1/5 multiple vitamin-mineral tablet (made for adult humans)
50 mg taurine

provides 413 kcalories, 23.9 g protein, 17.4 g fat
see tables for a cat's caloric needs

Cystine stones form because of a genetic defect that causes excess urinary excretion of cystine. Signs of cystine calculi do not appear before 3 to 5 years of age. Treatment is surgical removal. The recurrence rate is high, however, which makes prevention important. There is no proven successful means for preventing of calculi reformation. Protein-restriced diets and increasing urine production might help. The following diets restrict protein and promote urine production.

1 1/2 ounces tofu, raw firm (43 grams)
2 cups potato, cooked with skin (246 grams)
2 tablespoon vegetable (canola) oil (28 grams)
1/4 teaspoon salt substitute-potassium chloride
1/2 teaspoon bone meal powder (3 grams)
1 multiple vitamin-mineral tablet

provides 584 kcalories, 12.7 g protein (meets 100% of recommended requirement), 32.2 g fat
Supports caloric needs of 17 to 18 pound dog.
Provides 101 percent of protein and 166 percent of methionine requirements.

Straining to urinate and voiding small amounts frequently, often with blood, are signs of urinary tract obstruction in cats. A great number of both males and females are not obstructed with calculi, however. Most cats with these signs and no obstruction have idiopathic lower urinary tract disease where a complete workup shows no cause. Almost one percent of all cats in the United States show signs of this problem and of those the majority suffer not from stone formation but the idiopathic nonobstructive problem, making it the most common cause of clinical signs of lower urinary tract disease. The incidence of this problem in clinical female cats is 58 percent and in males 79 percent. Cats with idiopathic lower urinary tract disease are far more likely to be fed dry commercial cat food that nonaffected cats. Affected cats do not respond to medical management. Their diet must be changed. Feeding a canned commercial cat food solves the problem. Feeding any one of the diets in this website for normal cats or ones affected with lower urinary tract disease also solves the problem. The solution to the problem is to increase a cat's water intake. Adding table salt to any diet will accomplish this.

1. Hoppe Astrid E. 1994. Canine Lower Urinary Tract Disease. In The Waltham Book of Clinical Nutrition of the Dog and Cat. Edited by J. M. Wills and K. W. Simpson, 335-352. Oxford: Pergamon Press.

2. Markwell Peter J and C. Tony Buffington. 1994. Feline Lower Urinary Tract Disease. In The Waltham Book of Clinical Nutrition of the Dog and Cat. Edited by J. M. Wills and K. W. Simpson, 293-311. Oxford: Pergamon Press.

3. Buffington, C. Tony. 1992. Nutritional Aspects of Struvite Urolithiasis in Dogs and Cats. In Nephrology and Urology. Waltham Symposium Number 16. Edited by C. Tony Buffington and James H. Sokolowski, 51-57. Vernon: Kal Kan Foods.

4. Morris, James G. 1995. Nutrition and Nutritional Diseases in Animals. 18-1 to 18-11. Class Notes for Veterinary Medicine 408, School of Veterinary Medicine, University of California, Davis.

5. Lulich, Jody P., Carl A. Osborne, Larry J. Felice, David J. Polzin, Rosama Thumchai and Sherry Sanderson. 1992. Calcium Oxalate Urolithiasis. In Nephrology and Urology. Waltham Symposium Number 16. Edited by C. Tony Buffington and James H. Sokolowski, 69-74. Vernon: Kal Kan Foods.

6. Kirk Claudia A., Gerald V. Ling, Charles E. Franti, Janet M. Scarlett. 1995. Evaluation of Factors Associated With Development of Calcium Oxalate Urolithiasis in Cats. Journal American Veterinary Medical Association 207: 1429-1434.

7. Senior, David F. 1992. Urate Urolithiasis. In Nephrology and Urology. Waltham Symposium Number 16. Edited by C. Tony Buffington and James H. Sokolowski, 59-67. Vernon: Kal Kan Foods.

8. Buffington C. Tony, Dennis J. Chew, Michael S. Kendall, Peter V. Scrivani, Steven B. Thompson, Jean L. Blaisdell, Bruce E. Woodworth. 1997. Clinical Evaluation of Cats with Nonobstructive Urinary Tract Diseases. Journal American Veterinary Medical Association 210: 46-50, 1997.