Eight cats were fed a dry commercial cat food and after six months dev
eloped urinary struvite crystalluria with alkaline urine. The animals
were subsequently divided into two groups and fed either a dry or a ca
nned struvite calculolytic diet. The crystalluria was reduced after fi
ve to six weeks with both treatment diets. Decreased crystalluria coin
cided with a reduction in urinary pH and an increased titratable acidi
ty. The highest food acid load, determined by the lowest undetermined
anion, was found with the dry diet and resulted in the highest renal h
ydrogen excretion, measured as net acid excretion.