Litterbox problems are among the most common reasons for a cat to be brought in for exam, and one of the more common reasons for euthanasia. There are many possible causes, including diabetes, liver disease, kidney disease, bladder or kidney infections, bladder stones, cancer, Feline Urologic Syndrome, litter or a litter box the cat doesn't like (odor, texture), a dirty litter box, placing the litter box in a location the cat doesn't like, even other cats in the household causing anxiety or physically keeping the cat away from the litterbox.
A physical examination, urinalysis, and bloodwork will help determine the cause. Sometimes x-rays or abdominal ultrasound are needed to look for specific problems like stones, cancer or pyelonephritis. Urine cultures are used to confirm infections and to guide antibiotic treatment. If no medical problems are found, an antianxiety drug may be helpful, along with pheromone therapy.
Feline Urologic Syndrome can be fatal to male cats. The small crystals that form in the bladder can block the urethra, causing kidney failure and sometimes rupture of the bladder. If your cat is making frequent trips to the litter box and isn't producing much urine with each trip he should be examined immediately. Caught early, this problem can usually be controlled by special diet alone. In some male cats where the problem goes undetected and untreated, major surgery may be needed to save the cat's life.