For the past 50 years, the consensus has been that dietary modification is beneficial for treating chronic renal failure (CRF) in dogs; however, opinion varies about the type of modifications that can be used safely and effectively. The objective of this double-blind, randomized, controlled clinical trial was to determine whether a specifically designed renal failure diet (characterized by lower protein, phosphates, and sodium and higher omega-3 fatty acids) was superior to a typical adult maintenance diet in minimizing uremic crisis and mortality rate. After qualifying for this study and being fed a combination diet to minimize variability due to previous dietary consumption, 38 dogs of similar CRF status were divided into two dietary groups and evaluated for up to 24 months. Blood acquisition and assay, urinalysis, blood pressure measurement, and patient management were performed for all dogs. Dogs receiving the renal failure diet lived at least 13 months longer and had a slower decline in renal function and fewer uremic crises than those in the maintenance group.
COMMENTARY: Although ample evidence has supported the contention that low-phosphate diets slow progression of experimental CRF in dogs, this is the first controlled study showing that a low-protein, low-phosphate, low-sodium diet resulted in fewer crises and delayed progression of chronic renal failure in dogs with spontaneous CRF. The experimental diet (Hill's k/d) differed from the control (maintenance) diet in many respects, so it is not clear which elements or combination contributed to the renal-sparing effect.
Clinical evaluation of dietary modification for treatment of spontaneous chronic renal failure in dogs. Jacob F, Polzin DJ, Osborne CA, et al. JAVMA 220:1163-1170, 2002.