The No. 1 reason cats are taken to a veterinarian (outside of preventive care) is for Feline Lower Urinary Tract Disease (FLUTD), a serious disorder that affects the urinary system of cats.

FLUTD often causes cats to urinate outside the litter box, a classic warning sign of illness that you can see -- and smell. Other symptoms include cats straining to urinate, crying out in the box or going more frequently.

Sadly, these signs are often misinterpreted as behavioral problems that end up getting the cat sent to a cage in a shelter instead of to a veterinarian for the medical treatment he needs.

While FLUTD may strike any age or gender of cats, it is more frequently seen in middle-aged and overweight cats. Factors that increase the risk include lack of exercise, stress and chronic dehydration.

Tips for avoiding FLUTD include: