Struvite uroliths are comprised of magnesium, ammonium and phosphate and especially like to form in urine that is alkaline (higher pH). In dogs, struvite uroliths commonly occur when there is a concurrent urinary tract infection (UTI). In dogs that formed struvite uroliths due to a UTI, the prevention of recurrence is aimed at avoiding future UTI's with the use of antibiotics, and the dog's diet is usually not changed. In most cats and in some dogs, there is no UTI and the primary management of the disease is dietary. Dietary strategies to prevent struvite uroliths are primarily focused on decreasing the concentration of struvite precursors and acidifying the urine. Decreasing the struvite precursors is first accomplished by increasing water consumption by the methods discussed above. In addition, the amount of magnesium, ammonium and phosphate in the diet are reduced. Since the majority of ammonium and phosphate in the urine comes from the protein in the diet, the diets designed to prevent or even dissolve struvite stones are low in protein. The amount of protein in foods designed to dissolve struvite uroliths is so low that careful monitoring of the patient is necessary when dietary dissolution of struvite uroltihs is employed instead of surgical removal. This may include frequent and repeated radiographs (x-rays) to ensure that the diet is actually causing the stone to dissolve as well as blood tests. Unfortunately, low protein diets cause the urine to be alkaline which increases the likelihood of struvite formation. To counter this effect, diets designed to prevent or dissolve struvite uroliths have urine acidifiers added to them such as the amino acid methionine. Close monitoring for a low urine specific gravity, low urine pH and lack of struvite crystals with frequent urinalysis is crucial to effectively preventing recurrence of struvite uroliths.