Diet for a Feline With Struvite Crystals

Feline lower urinary tract disease (FLUTD) is a multi-factorial disease, and struvite crystals are a common cause. Struvite crystals consist of ammonium, magnesium and phosphate, and are formed when the cat's urine becomes over-saturated with these chemicals in the presence of a urine pH above 6.5. Symptoms of struvite crystals are difficulty urinating, bloody urine and urination in inappropriate locations.

Determining Significance

Struvite crystals found in the urine of an apparently healthy cat with no symptoms of urinary disease may have no clinical significance, particularly if the urine sample is aged. Struvite crystals may form as artifacts in urine over time. Always use a fresh sample of urine to test for struvite crystals.

Regulating pH

Elevate the protein level in the cat's diet. The goal is to decrease the urine pH to 6.5. According to a 2003 study by Masayuki Funaba, giving the cat a diet with a crude protein level of 55 percent results in a lower pH and fewer struvite crystals than a diet containing 29 percent crude protein.

Diets with reduced carbohydrate levels also decrease the pH of the urine.

Ask your veterinarian to recommend a proper cat food. Choose food with animal protein as the primary ingredient. Consult the food label to determine the primary ingredient of the food being considered.

Avoid foods with grains as the primary ingredient; these are high in carbohydrates.

Have your vet measure the pH of the cat's urine periodically, to ensure that the pH remains near 6.5. If the urinary pH remains high, consider changing to a food with a higher protein content and/or a lower carbohydrate content. Urinary pH should not be allowed to fall too low. Calcium oxalate crystals form at low urine pH levels.

Urinary acidifiers such as ammonium chloride should not be administered to cats receiving a high protein, low carbohydrate diet.

Controlling Saturation

Though diets restricted in magnesium and other minerals are available, controlling the saturation of urine with magnesium, ammonium and phosphate is the ideal method to decrease struvite formation. Creating a diluted urine is the best way to do this.

Increase the moisture content in the diet by feeding the cat canned food rather than dry. Doreen Houston's study confirms that feeding a canned diet decreases the specific gravity of the urine, resulting in more diluted urine.

Increased water consumption will also help produce diluted urine. Encourage water consumption by supplying water fountains and bowls, leaving water faucets dripping or adding water directly to the cat food.