House soiling is defined as a feline urinating or defecating outside of its normal elimination areas, i.e. in a litter box. Usually the reasons for the box not being used are temporary and relatively benign, such a minor illness or stress, and the cat resumes using its box when the issue is resolved. But a feline defecating or urinating away from its litter box can be symptomatic of a chronic health problem or serious illness, as well. Since veterinarians consider house soiling to be a symptom of an underlying physical or emotional problem, owners seeing this issue in their cat should consult with its veterinarian to discover and resolve its cause or causes. Regardless of the reason for the cat's house soiling, once it begins defecating or urinating outside of its box, it can quickly fall into the habit of doing so, another reason why this problem should be addressed quickly.

One of the conveniences of cat owning is that felines adapt readily to defecating in litter boxes, eliminating the need for owners to frequently let the animals in and out. If the owner keeps the litter box and the area around it reliably clean, the cat, in turn, will consistently use the box and bury its waste. But it's not unusual for even the best-trained cat to have an occasional "accident" over the course of its life.

Feline house soiling is defined by:

The condition is generally broken down into two categories, behavioral and medical. 

Behavioral soiling symptoms often include:

Medical house soiling is categorized by:

It should be remembered that animals "talk" through defecating and urinating, and in some cases, the message that a house soiling feline may be sending its owner is that it dislikes its litter box. The most common soiling issues centering around the litter box itself include:

Unneutered male cats will mark their territory with urine, which is why it is recommended that male kittens be neutered at no later than five months to prevent this behavior. While this urine spraying is done to protect a cat's territory from other male cats, this type of soiling, as well as defecating, can be in response to stress. Pets are very responsive to even tiny changes in their environment, and what a feline can consider stressful includes:

Because unusual elimination can be symptomatic of various feline illnesses, when house soiling occurs, cat owners should note the presence (or absence) of other symptoms, such as lethargy, flatulence, loss of appetite, discomfort, and restlessness or pacing.

Medical causes of house soiling can include:

Cat owners should remember that not all symptoms may manifest at once. Therefore, if they are noticing only house soiling as a symptom, but have no cause to feel that it is behavioral in nature, an immediate medical examination of the animal is warranted.

Unless the veterinarian is provided with likely proof that house soiling is being caused by behavioral stressors, his or her first course of action will to be to eliminate medical causes through testing. Such medical testing includes parasitic testing through stool samples, blood and urine testing, and thyroid testing.

If the cause is not a medical problem, and the animal has been neutered, than the vet must look at behavioral issues, and the cat's owner should expect to be queried as to changes in the cat's and the household's routine, litter box practices, new humans and animals in the cat's life and more. The cat's owner can help here by keeping notes on when symptoms appeared, as well as changes to both the cat's and household's routine. Nothing should be considered inconsequential here, including minor home remodeling. Cats have been known to leave owners "messages" when a room's been repainted without the cat's permission, for example.

Courses of action and prognoses vary widely and always, timely detection and intervention are key. Almost all of the medical causes of house soiling can be treated with medication and diet or a combination of both. In some cancer situations, surgery may be called for. Treatment time can range from weeks to months depending on the severity of the condition, and may or may not require hospitalization.

Treatment here often calls for observation, which can include examining offending matter. It can be helpful to install cameras to record cat behavior. When a cause is found, treatment can range from changing or restoring a litter box or litter type to adding more litter boxes and getting modified litter boxes, to separating or neutering animals. Because cats will quickly adopt the habit of house soiling, owners should move quickly to make corrections to discourage this. They should also keep in mind that cats will not be willing to compromise to achieve this, which may require the restoration of a litter box to an undesirable location, using smelly litter, etc. 

For soiling issues with medical causes, owners may expect take-home treatment and follow-up visits, depending on the severity of the cat's case. Behavioral therapy length will depend on how quickly the cat's cause is diagnosed, and the owner implements changes. In both cases, the owner should thoroughly clean, disinfect, and spray with a neutralizing agent all soiled areas to discourage future soiling. Cats should never be punished or reprimanded for such actions, as they are infective and can lead to increased soilings from a stressed-out cat. And owners may be less stressed out by such soilings themselves if they consider them from the cat's perspective. It's not a mess, but a warning of a problem that needs correcting.