"Feline lower urinary tract disease" (FLUTD) refers to a group of diseases of the urinary tract. In general, these diseases are inflammatory infections and urinary calculus that occur in male and female cats.
Cats suffering from FLUTD can exhibit one or all of the symptoms described here: straining to urinate, blood in the urine, frequent urinating with only small amounts actually voided, and urination in inappropriate places.
Also, urinary calculus may lodge in the male urethra, causing complete obstruction. This means the cat can't urinate at all. When this happens, your cat is in a serious, life-threatening condition, and needs to be taken to the vet immediately.
Factors increasing the risk of FLUTD:
Inactivity: Cats who are inactive seem to suffer from FLUTD more often than those who get regular exercise. Obese cats also tend to be more prone than those of normal weight.
Age: FLUTD can occur in any cat, but most commonly occurs within the two to five-year age group.
Gender: Male cats are at greater risk of urethral blockage, probably because their long narrow urethra increases the likelihood of blockage.
Diet: Some diets may play a part in some types of FLUTD. Your vet will tell you whether you should feed your cat a specially formulated, commercially prepared diet for cats with FLUTD. He or she may make some other recommendations in regard to your cat's water intake, exercise and diet.