My pet has kidney problems and struvite gravel. Can I combine a kidney diet with a urine-acidifying diet or supplement?

Kidney problems and struvite are two disorders that are difficult to tackle simultaneously. This is because anti-struvite diets acidify the urine and this is undesirable in kidney patients. Kidney patients are less efficient in regulating the acid-base balance in the body. When a urine-acidifying diet or supplement is given, the animal’s kidneys are unable to raise the pH of the blood sufficiently, which can lead to acidosis (blood acidification). Acidosis can cause health problems in the long term. To prevent acidosis, kidney diets slightly raise the urine pH. This, however, increases the chance of the formation and precipitation of struvite.

In patients with kidney problems and struvite, a choice between two evils has to be made. In these cases, the priority goes to kidney failure, because animals with this condition can only be supported with a kidney diet. Struvite can be prevented by acidifying the urine and by increasing the urine volume. Since animals with kidney problems are less able to regulate the acid-base balance, increasing the urine volume is the only option for the prevention of struvite. We recommend that animals with these two disorders should be prescribed the wet food variant of a kidney diet. This minimises the burden on the kidneys and dilutes the urine, which reduces the chance of struvite formation.