Frequent trips to the litter box
Straining to urinate
Crying or vocalizing while urinating
Producing only small amounts of urine
Urinating outside the litter box
Blood in the urine
Excessive licking of the genital area
Strong-smelling urine
Restlessness or discomfort
Hiding or acting unusually withdrawn
Loss of appetite
Lethargy
Inability to urinate at all
Swollen or painful abdomen