Nutritional management of lower urinary tract disease in cats

The two most common causes of feline lower urinary tract disease (FLUTD) are idiopathic cystitis and urolithiasis, together accounting for up to 80-90% of cases¹. Overall recurrence rates of up to 40-45% have been reported¹.

By definition, the cause of idiopathic cystitis in cats remains obscure, although both stress and abnormalities of the urothelial barrier have been reported. At present, the recommended approach to managing cats with recurrent idiopathic cystitis is¹:

Environmental enrichment Reduction of stress Encouraging water intake

Additional medical therapy in refractory cases (which may include analgesics and amitrityline)

Fundamental to urolith development is supersaturation of the urine with the calculogenic crystalloids – without this crystal and urolith formation will not occur.

Other factors that may play a role include genetics, age, concurrent diseases, gender, and urine composition of various promoters and inhibitors of crystal formation. Calculogenic crystalloids may be present in urine in one of three concentration ranges:

• Supersaturation: if the crystalloid concentration falls in this zone, spontaneous crystal formation and growth may occur.
• Metastable saturation: concentrations in this zone will not permit spontaneous crystallisation, although growth of pre-formed crystals is possible.
• Undersaturation: in this zone the urine is undersaturated and crystal dissolution will occur.

There are two types of urolith: struvite (magnesium ammonium phosphate) and calcium oxalate, which account for 80% or more of all feline uroliths. Today, the prevalence of struvite and oxalate uroliths are similar. While the development of struvite uroliths is sensitive to urine pH (the crystalloids being much less soluble in alkaline urine), the development of oxalate crystals is much less influenced by urine pH.

Feline UR St/Ox has been specifically designed to benefit cats with FLUTD – promoting a higher volume and lower concentration of urine, urine with a low RSS and APR for both struvite and oxalate.

Feline UR St/Ox provides:

• a moderate and proven safe salt content (1.2% as fed) in the dry formulation to encourage an increased urine volume,
• increased urine volume and decreased urine specific gravity (SG), to promote more frequent urination and a lower concentration of substances that may irritate the urothelium,
• added omega-3 fatty acids and natural GAGs, that may help to reduce bladder inflammation and aid the integrity of the bladder lining.

Feline UR St/Ox contains reduced fat and optimum protein levels to help prevent obesity, a known risk factor for urolithiasis. Tested with both RSS and APR (which provide different and complementary information about the saturation of urine with crystalloids), Feline UR St/Ox promotes a urine:

• undersaturated for struvite, producing an environment where struvite crystals and stones can dissolve, and where their formation is prevented,
• in the low metastable range for calcium oxalate – an environment that should prevent de novo crystallisation and greatly reduce the risk of any crystal/stone growth,
• in a controlled pH range (6.0-6.3), ideal for managing struvite crystalluria and not detrimental to oxalate.