Diet and the Urinary Tract

Many cats suffer from urinary tract disease during their adult lives. For some, it is a one-time incident. For others, it becomes a chronic battle to maintain good health. In most cases, these cats suffer from what is termed “idiopathic urinary tract disease.” This means that we do not know what causes their disease.

Diet certainly plays a role in urinary tract health, but it is not the only factor and is probably not the most important factor. If you’d like to learn more about urinary tract disease, read the article in the Cat Medical Topics section entitled Urinary Tract Disease, or click here to read now. Keep reading to learn about some of the dietary factors that may play a role in urinary tract health.

Most everyone has heard of ash. However, what ash is and where it comes from is a bit of a mystery to many. Ash is not an ingredient that some pet food manufacturers add to their foods and others do not. Ash is a component of all pet foods.

Ash comes from bones that are used in the production of meals. Meals are the dry protein sources used in dry pet foods. For example, chicken meal is made from chicken meat and bone, primarily necks and backs. When the meal is made from the raw ingredients, it is cooked at high heat. The bone that is left after the cooking process, is the ash.

Ash is high in phosphorus, magnesium, and calcium. Because of this, high ash pet foods tend to be high in the above minerals. The dry protein source that is lowest in ash is chicken by-product meal. Although many people don’t like to see chicken by-product meal as a pet food ingredient, it is actually the best protein choice for cats that have a history of urinary tract disease.

Phosphorus has been implicated as a factor in the progression of renal disease.  In patients diagnosed with varying levels of renal compromise, phosphorus has several adverse effects.  The mechanism is not very well understood, but various studies have shown a more rapid rate of deterioration of renal function in animals eating a high phosphorus diet.  Possible causes for the deterioration are nephrocalcinosis, hyperparathyroidism, and lipoprotein abnormalities.

Phosphorus can also be problematic for cats suffering from FLUTD associated with struvite crystal formation.  Phosphorus is one of the components of struvite crystals.

Magnesium is another mineral that is a component of struvite crystals or stone. Magnesium should be restricted in the diets of cats, but should not be severely restricted. The reason for this is that when it is severely restricted another type of crystal may develop in the urinary tract, calcium oxalate.

A final dietary factor that is probably the single most important factor when it comes to preventing urinary tract disease is acidification. What this refers to is the ability of the diet to acidify the urine. This is accomplished through the addition of ingredients to acidify the formula. Methionine is an amino acid that is commonly used as an acidifier. The critical information to have is the amount of acidification. Diets that are over-acidified may lead to calcium oxalate crystals and stones and diets that are not acidified enough may lead to struvite crystals. The ideal pH is 6.1 – 6.5, or somewhere within this range.

One thing to remember about urine pH is that it is also affected by factors outside of diet. Cats that are stressed or ill may have a much higher urine pH because of the physiologic process that occurs within the body in response to stress.

If your cat is suffering from urinary tract disease, work closely with your veterinarian to choose an appropriate diet that will help improve the effectiveness of your management plan.