The effect of non-absorbent hydrophobic sand litter on the urine protein-to-creatinine ratio in feline urine.

Background: Proteinuria can be quantified through the measurement of the urine protein-to-creatinine ratio (UPC). Voided urine samples in cats are often exposed to a non-absorbable litter substrate prior to collection and urinalysis. Little is known about the effect exposure to such substrates has on pre-analytical variability of UPC measurements.