Not all cats will urinate or defecate outsides the litter box, but when they do, this is usually a sign to most owners that something is “off” with their cat. Feline inappropriate urination is one of the most common reasons owners bring their cats to the vet and the most common cause for cats to be euthanized. Before discussing the main causes for this issue, it is important to understand the difference between “spraying” and “inappropriate urination”. Spraying occurs more frequently in male cats and tends to happen on vertical surfaces. Your cat may raise its tail and spray urine for a very short period of time on a wall, the side of a couch, a door, etc. Inappropriate urination, however, tends to occur on more horizontal surfaces. You might see your cat squatting and posturing as it normally would to urinate in the litter box, and find urine on rugs, in laundry baskets, on bedding, etc. In addition to finding urine outside the litter box, you may also find bowel movements as well. These kinds of accidents may be very close to the litter box or in a completely different location.
Two of the more common causes for inappropriate urination for both male and female cats are urinary crystals and bladder infections, both of which are very irritating to the bladder. Urinary crystals can rub against the bladder wall and cause the wall to become swollen. These crystals can develop simply because some cats do not drink enough water and therefore do not urinate and flush out their bladder as frequently as they need. Urinary crystals and infections can affect the chemistry of the urine and cause protein and blood to leak out into the urine.
As your cat urinates, the protein and blood can burn and be painful. Some cats associate the burning feeling with their litter box and, as a result, stop using their box. Other cats will urinate in their box but may also urinate in smaller amounts and with greater frequency in places outside their box because the burning creates a sense of urgency where they may not make it to the box on time. If left untreated, crystals and bladder infections can lead to bladder stones or kidney infections and, in male cats, a blockage of the flow of urine which is a life-threatening condition.
Cats sometimes urinate inappropriately due to stress. This includes stresses within their environment, such as the addition of a new baby to the home, a move or relocation, or some other change in routine internal stresses that may not be as obvious. Just as stress can manifest itself in different ways in humans, stress in cats can do the same. Researchers have found that stress can cause the bladder wall to become thick and inflamed, once again causing protein and blood to leak out into the bladder, which can lead to pain and burning when they urinate.
Cats can also have very strong behavioral preferences to their litter, litter box, and litter box location. Making sure that the litter boxes are easily accessible to all cats in the household is important. Many behaviorists recommend that owners have one more litter box than the number of cats in the house. (For example, if you have 3 cats, you should have 4 litter boxes.) Some cats prefer to have their box covered while others do not, and some cats are very particular about the type of litter that their box contains or how frequently it is cleaned.