Why Is My Cat Peeing Outside the Litter Box?

Start with a vet visit

The ASPCA says house soiling is a common problem in cats, and that while behavior is often the cause, medical issues are sometimes to blame, so a cat that eliminates outside the litter box should be checked by a veterinarian first. The Cornell Feline Health Center says any medical condition that interferes with a cat's normal urination or defecation can cause litter box problems, and advises a thorough physical examination. VCA Animal Hospitals says ruling out medical problems takes a complete physical examination, a urinalysis and, in some cases, additional diagnostics.

Signs worth telling your vet about: Cornell's page on lower urinary tract disease lists difficult or painful urination, urinating more often, crying out while urinating, blood in the urine, urinating outside the litter box and frequent licking of the genital region. On the ASPCA's litter box page, a cat that keeps going into the box and produces only small amounts of urine may have a urinary tract infection; feline interstitial cystitis is described as very serious and possibly life-threatening, to be treated immediately by a veterinarian; and a cat with kidney stones or a blockage may go into the box often and cry when it tries to go. For the signs that make it an emergency, see the next section.

At any age, the ASPCA says some conditions may increase urine production: kidney failure, kidney infection, diabetes, liver disease and increased thyroid hormone levels. It says these cats generally pass large amounts of urine without straining, may drink more, eat less, lose weight or have a poor coat, and need a thorough work-up from a veterinarian. If your cat seems to be drinking more, see our guide to how much water a cat should drink.

When it is an emergency

International Cat Care says that if your cat is trying and failing to pass urine, or only passing very small amounts of urine, it is an emergency and your cat needs to be seen immediately. Among the signs of urinary disease it lists difficulty passing urine, where a cat may strain, scratch in the litter tray for long periods or cry out in pain, and it says straining to pass urine may indicate a urethral obstruction, a blockage, which is an emergency.

Cornell calls urethral obstruction a true medical emergency, and says any cat suspected of having it must receive immediate veterinary attention. It says the time from complete obstruction until death may be less than 24 to 48 hours. Cornell says an obstructed cat may strain to urinate, make frequent attempts to urinate and produce little, if any, urine, and that as time passes it typically becomes much more distressed, often crying out in pain.

Cornell says male and neutered male cats are at greater risk than females because their urethra is longer and narrower, and the ASPCA says male cats may develop an obstruction of the urinary tract that makes it impossible for them to urinate, which it calls a medical emergency that needs immediate veterinary care. The University of Illinois College of Veterinary Medicine lists the first signs as vocalizing while trying to urinate, straining repeatedly without success, small amounts of bloody urine, trying to urinate outside the litter box, and vomiting. It says that as a blockage goes on, a cat may appear lethargic, become less active, stop eating, and even become weak and collapse, and that a cat showing these signs should go to a vet right away.

Senior and arthritic cats

International Cat Care says arthritis is very common in older cats and lists difficulty using the litter tray, with accidents outside it, among the signs. It suggests a tray with at least one low side and soft, sandy litter, and asks you to contact your veterinary team if you see any signs of arthritis, since even subtle changes can be important. The ASPCA says older or arthritic cats may have trouble with certain litter boxes and suggests switching to one with low sides; Cornell says elderly cats and cats with mobility problems need low-sided boxes. VCA notes that older cats can find stairs an obstacle to a litter box in the basement.

Spraying or peeing? Male and female cats

Urine marking is a different problem. The ASPCA says a marking cat will regularly use its litter box but also deposit urine elsewhere, usually on vertical surfaces, and usually less than it would leave in the box; it says the cause and treatment are entirely different from other litter box problems. Cornell says cats usually spray on vertical surfaces, like the backs of chairs or walls, and do not squat to spray, as they do to urinate.

Both sexes can spray. Cornell says cats that spray are usually unneutered males and, to a lesser extent, unspayed females, but that 10 percent of neutered males and 5 percent of neutered females also spray. It says neutering or spaying reduces the influence of hormones on spraying, and that cats may spray when they perceive a threat to their territory.

How to stop it: fix the litter box

Once medical causes have been ruled out, Cornell says, the detective work begins. The ASPCA's steps: remove covers and liners from all litter boxes, scoop at least once a day, have one box for each cat plus one extra, and if your cat soils in just a few spots, place litter boxes there. Cornell says most cats prefer an uncovered box, unscented, finer-textured litter about one to two inches deep, and a quiet, private spot away from where they eat that they can reach at any hour.

The ASPCA notes that a cat used to one litter may dislike the smell or feel of a new one, and that in some homes one cat controls access to the boxes and keeps the others away. For scooping and full litter changes, see our guide to how often to change cat litter; while you work through a litter problem, the Animal Humane Society cited there recommends scooping at least twice a day.

Cleaning up, and what not to do

Clean accidents thoroughly with an enzymatic cleanser designed to neutralize pet odors, and do not use an ammonia-based one, the ASPCA says. Cornell says cleaning works best soon after something is soiled, that odors must be neutralized, not just deodorized, and to avoid products containing ammonia or vinegar, which smell like urine. The ASPCA also suggests making the soiled spots less appealing to your cat.

Do not scold your cat, carry or drag it to the box, or rub its nose in urine or feces, the ASPCA says. Cornell says never to hit, kick or scream at a cat: punishment like that is not only ineffective, but the anxiety it causes may make house soiling worse. If the problem continues, Cornell says a veterinary behaviorist may give important insight into the cause.

If you are replacing a box, our sources point the same way: the ASPCA suggests removing covers and, for an older or arthritic cat, a box with low sides; Cornell says most cats prefer an uncovered box; and International Cat Care's guide to choosing a litter tray says large cats may find smaller hooded trays hard to use. Our stainless steel litter box picks give each box's dimensions and say whether it has a lid, but none of the three is sold as low-sided: one has a lid, and Kirecoo's listing calls its 6-inch sides "High Sided". For an older or arthritic cat, use that page for sizes only, and look for a box with at least one low side.