Frequent urination, excessive squatting in litter trays or fowl smelling urine are all symptoms associated with Feline Urinary Tract Disease. Commonly seen in male cats, urinary Tract Disease is caused by the formation of struvite crystals in the bladder. These crystals are made up of high levels of magnesium, phosphate and calcium and can become quite large if left untreated. Many cheap supermarket foods have high levels of these compounds and are therefore more likely to result in the formation of crystals.