Inappropriate elimination/toileting problems refers to urination or defecation by a cat in a location that is unacceptable to humans, namely somewhere in the home and outside the litter box. Inappropriate elimination can be due to many different factors, and should not be confused with marking behavior, the most common of which is spraying. When toileting problems in cats are not medically related, they are often triggered by issues related to the litter box. If you have ever been reluctant to use a “porta-potty” at a crowded event, then you can probably relate to how the cat might feel.

It’s important to remember that ‘not using the litter box’ is a nonspecific description. Medical disorders of the urinary or digestive system can cause inappropriate elimination. Cats who are ill may not reach the box; for example, cats with bladder inflammation may not be able to “hold it” to go to the box, or cats with arthritis may not be able to posture to defecate inside the box. So, it is wise to consider a veterinary checkup when “accidents” are first noticed. If no evidence of a medical problem is identified, your veterinarian can help you consider behavioral reasons to the abnormal elimination behavior. It is easier to intervene early than after bad habits have been established.

There are several reasons a cat might choose to avoid a litter box. Chief among these are dirty litter boxes, not having a litter box nearby in an easily accessible location, having to share a litter box with other cats, placement of the box in an area that is scary or uncomfortable to the cat (either physically, or due to the presence of an uncomfortable social situation), or a truly pathological aversion to some aspect of the litter box (enclosed/open, size, litter type, etc.). Of these, the most common issue relates to litter hygiene.

Good Litter Box Hygiene, and Other Box Issues

Good litter box hygiene is essential for all cats. Humans dislike dirty toilets and so do cats. Furthermore, cats have a greater ability to smell odor than do humans, and they have fur to which odor clings. How do you know whether your cat wants a ‘cleaner’ litter box environment? If your cat jumps into the box to use it immediately after it has been cleaned, chances are the cat is fastidious and his or her litter box needs may not be being met.

Besides hygiene, there are other litter box–related issues to consider as a cause for inappropriate elimination. ALL indoor cats need clean litter boxes in a place they can reach easily. But otherwise, each cat has its own set of preferences. If your cat consistently uses the litter box with no problems, feel free to keep on doing what you are doing now. But if your cat is going outside the box, the issue does not seem to be marking behavior, and it is not a medical issue, then consider these factors associated with improved litter box use:

  1. A litter box of the appropriate size; cats prefer large boxes (1.5 times the length of the cat including the tail).

  2. Multiple boxes; the general rule is 1 box more than you have cats.

  3. Ideally, keep a box on each floor of a multilevel home.

  4. Scoop litter at least daily, and better yet multiple times a day.

  5. Empty the box – even if the litter is scoopable – at least twice a week or more often if multiple cats use the box.

  6. Avoid box liners as most cats do not like them.

  7. Avoid deodorants or other scents (e.g., lemon) in litters, liners, or boxes. Most cats do not like deodorants and extraneous scents. These are added to please human noses, but with the consequence of allowing the person to decide the box smells OK (to the person!) and doesn’t need to be cleaned as often as it really does.

  8. Try different textures or types of litter—and there are many to choose from! Some cats prefer one over another by a lot. If you try the change, it is best to use the new litter type in one box while keeping the old litter available too, just in case the cat really dislikes the new.

  9. Keep litter at a depth the cat likes. You may have to find out what depth your cat prefers by offering him or her choices. How will you know? Studies have shown cats will dig in a litter environment that they like.

  10. Use undamaged, clean boxes. Wash boxes weekly in hot water and soap. Rinse multiple times and then dry before returning to use. Replace when scratched because scratches hold odor.

  11. Avoid hoods. Humans like hoods, but hoods trap odor. Cutting away the top part and leaving 3 sides can stop spillage and keep in litter that would have been scratched out, but allow air to circulate. Of course, some cats don’t mind hoods, and if so, that’s fine too.

  12. Put boxes in locations the cat likes. Cats like locations that are easy to get to. They like boxes placed where they don’t feel “trapped” and they can leave the box in many directions (they don’t like boxes in the corner or in an enclosure). They dislike having their trip to the box interrupted or blocked by a dog, a child, or another not-so-friendly cat. They want a box that is easy to climb in and out of, especially if the cat has arthritis or is small.

  13. Anywhere the cat has eliminated outside the box requires intense cleaning. First, clean with soap and water. Soak with club soda multiple times, blotting up the liquid until you can detect no trace of the odor or urine, feces or soap. Then, use a good odor eliminator (such as Anti-icky poo/AIP or another type made for the purpose). If possible, replace carpet and seal subfloors.

What Is if It Not Medical and Not Hygiene?

Don’t punish your cat for going outside the litter box. It is always counterproductive and damages your relationship with the cat. They cannot understand what you are trying to convey, even if you take them back to the “scene of the crime.” On the other hand, if you notice your cat leaving the litter box after using it correctly, feel free to offer praise and reward (this might be cuddling, or play, or a small food treat).

Consider the pattern of use. Cats—especially those who are anxious or worry—develop preferences and aversions that may not be rational to a human but make sense to a cat. If the cat has been scared in one circumstance, he or she may associate that with a litter box. Is there one box that is avoided while others are still used? Is there a location where the cat keeps returning, and could you put a box nearby?

Consider what surface they do like to use. Do they find cloth, like a towel on the floor or a basket of clothes? Is there a specific flooring that is the target of use? Sometimes, you can try to replicate the preferred substrate inside a box. For example, cats that use cloth might be willing to use an old towel placed inside the box (and which you wash often). You may be able to slowly shift that box back to a typical cat litter over a period of time.

Consider if the behavior is associated with a change in relationship between cats in the house, a new cat, a new dog, or a new human. Has the cat’s favorite person been away from home, or is there some other possible trigger event for the problems? If you think this is the case, work with your veterinarian and/or a specialist in veterinary behavioral medicine to ensure that you understand the social dynamics and contributors to anxiety in the household.

As with most behavioral conditions, treatment will involve changing the behavior, changing the environment, and treating any anxiety experienced by the cat. If the cat is very anxious and unhappy, as part of a complete treatment program, antianxiety medication may help, and should be part of the conversation with your veterinarian.


Karen L. Overall, MA, VMD, PhD, DACVB

Source: From Cohn and Côté: Clinical Veterinary Advisor, 4th edition. Copyright © 2020 by Elsevier Inc. All rights reserved.


Cause: Hypertrophic cardiomyopathy is a type of heart disease in which the heart muscle tissue becomes excessively thickened. Hypertrophy is normally a good thing with muscle (as evidenced by the muscles of athletes), but unnecessary and unwanted thickening of the heart’s walls makes the walls rigid and unable to move properly, and crowds out the space normally reserved for blood, limiting the heart’s ability to sufficiently fill and pump effectively. The body may initially compensate for this “crowding” effect of hypertrophy, and no symptoms are seen, thanks to selective constriction of blood vessels in the body, retention of sodium that would otherwise be lost in urine, and so on. Over time, however, if cardiac hypertrophy continues to worsen, the body’s ability to control this problem becomes inadequate, the circulation can be compromised, and as a result, part of the fluid portion of blood seeps into surrounding tissues and can flood the lungs, a potentially serious condition called congestive heart failure.

Hypertrophic cardiomyopathy is a disease that frequently affects cats (it is the most common heart disease of the domestic cat) and virtually never affects dogs. It is thought to be of genetic origin, which explains why it is so widespread and difficult to eliminate or cure.

Hypertrophic cardiomyopathy is usually detected in one of four specific contexts:

  • •Abnormal sounds (heart murmur, gallop sound, or arrhythmia)are heard with a stethoscope during the veterinarian’s routine examination for other reasons. There are no symptoms caused by the hypertrophic cardiomyopathy, even though there may be significant heart wall thickening. This is the most common situation for first finding hypertrophic cardiomyopathy in cats. A similar situation where hypertrophic cardiomyopathy is an incidental (unexpected) finding is the detection of cardiac enlargement on a radiograph (x-ray) of the chest or an abnormality on an electrocardiogram/EKG.
  • The fluid retention caused by hampered circulation compresses the lungs or partially fills them with fluid. A cat in this situation is usually brought to the veterinarian’s because labored breathing and/or signs of “not feeling well” (lethargy, hiding, loss of appetite) are present.
  • Heart enlargement that occurs as a result of the cardiachypertrophy, causes stagnation of blood flow (poor emptying) in one or more of the cardiac chambers. This sluggish blood flow allows a blood clot to form inside the heart, which can then travel into the circulation, blocking off blood flow to all the organs and tissues “downstream” from the blockage. This very serious sequela of hypertrophic cardiomyopathy usually produces immediate, severe limping or paralysis of the hindlimbs because the blood clot commonly travels to the arteries that supply the back legs (aortic thromboembolism, or “saddle thrombus”). These symptoms can be very painful, and an immediate visit to the veterinarian is warranted if you see a sudden inability to use one or both hind legs or a front leg in your cat.
  • Genetic screening (blood test) identifies the genetic mutation for hypertrophic cardiomyopathy in a cat. There may or may not be any signs of heart problems, and the test simply indicates that the cat carries the potential for having—and transmitting to its future generations—hypertrophic cardiomyopath

Diagnosis: In any of the above situations, your veterinarian will likely suspect hypertrophic cardiomyopathy as a possible explanation. Your veterinarian will perform a thorough physical examination and take a complete medical history regarding your cat, asking you questions in particular concerning any of the symptoms described above, your cat’s past medical history, indoor versus outdoor lifestyle, current medications, and so on. Chest x-rays are usually essential since they can show the presence of fluid retention in the lung tissue or chest cavity (pulmonary edema and pleural effusion, respectively) and help to evaluate the possibility of other, completely different (“impostor”) problems with symptoms that mimic the symptoms of hypertrophic cardiomyopathy. A urinalysis and blood work, including a complete blood count (CBC), blood chemistry profile, and blood thyroid hormone level, may indicate problems with other organs; blood pressure measurement is also appropriate. It is important to have these results before establishing a treatment plan, to make sure preexisting conditions are not present to interfere with medications. A blood biomarker test (NT-proBNP) measures circulating levels of a substance produced by the heart muscle tissue and can be elevated in cats with hypertrophic cardiomyopathy. Your veterinarian may use this as an intermediate step because low levels mean it is very unlikely that a cat has hypertrophic cardiomyopathy, whereas very high levels are strongly suggestive of a heart condition (although not specific for hypertrophic cardiomyopathy). An echocardiogram, commonly called cardiac ultrasound, is the definitive test for hypertrophic cardiomyopathy. It might require shaving a bit of hair from each side of the cat’s chest but is otherwise like a human ultrasound: noninvasive, painless, and does not require general anesthesia. It allows assessment of all parts of the heart (walls, valves), blood flow through the heart (Doppler ultrasound), and gives an accurate depiction of cardiac function.

In some situations, cardiac hypertrophy may in fact be caused by a disease outside the heart, but which drives the heart to work harder (and become hypertrophied as a result). These non-genetic diseases, such as hyperthyroidism or hypertension/high blood pressure, are also screened for by your veterinarian. This is because it is possible to reverse and sometimes completely eliminate excessive cardiac hypertrophy if it is secondary to another disease.


Cats that are found to have hypertrophic cardiomyopathy without symptoms of the disease generally do not require medications. Some of these cats go on to develop congestive heart failure or blood clots, but some do not and instead lead normal life spans without symptoms. This is important because hypertrophic cardiomyopathy is not automatically a life-threatening disease.

Cats with hypertrophic cardiomyopathy that has triggered fluid retention (congestive heart failure) or a blood clot to the legs (aortic thromboembolism) are in need of medications to survive. These medications usually need to be given for the rest of the cat’s life, and an in-hospital stay (possibly in intensive care) may be necessary for the first few days if the condition is very serious or critical. The outlook for these cats is more guarded; some respond well to treatment and live comfortable lives for months to a few years on average, whereas others do poorly even with the most intense and comprehensive treatment. In most cases, the response (or lack thereof) to treatment becomes apparent in the first 48-72 hours after the beginning of therapy.

After hospitalization for congestive heart failure or aortic throm-boembolism, allow your cat to rest and recover at home, and be sure to give medication exactly as directed. It is important to understand that there is no cure for hypertrophic cardiomyopathy, since it is a disease of genetic origin, but that medication can control some symptoms and improve your cat’s quality of life. As the disease process continues, medication may need to be increased or changed. Understand the possible side effects of all medication being given so that you know what is normal and abnormal. You can ask your veterinarian for specific details in this regard since they vary depending on the medications used. Some diagnostic tests may be repeated periodically to monitor the hypertrophic cardiomyopathy and to assess medication effects.

Once hypertrophic cardiomyopathy is known to exist in your cat, it is important to avoid stressful situations for your cat. These can strain the heart excessively and cause the return of symptoms. Limiting physical activity to a minimum is a good idea. The behavior of cats often includes their own spontaneous physical activity and exertion (e.g., nighttime hyperactivity) that cannot be controlled, but at least situations that create more activity (such as playing fetch to the point of exhaustion) should be avoided. A very serious symptom of oxygen shortage in the body is a sudden change from pinkish to bluish discoloration of the oral mucous membranes (entire surface of the gums), and if you see this abnormality, called cyanosis, you should stop all activity and bring your cat to the veterinarian’s immediately if the blue color does not disappear on its own with a few minutes of rest.


Although there is no cure, cats that are asymptomatic require no treatment, and cats showing symptoms caused by hypertrophic cardiomyopathy can be treated with medications that help control or eliminate those symptoms. If symptoms are severe, your cat may need to be hospitalized and given oxygen and injections of medications, such as diuretics (to evacuate fluid quickly from the lungs) and a sedative (to reduce the intense adrenaline surge that places a great deal of strain on the heart). These more serious cases have a very variable outcome. Some cats respond very well to the medications, and their condition improves within a day or two of admission to the hospital, whereas some others (less commonly) may worsen despite intensive treatment.

Other medications are available that affect the heart’s contraction (calcium channel blockers, beta-adrenergic blockers) and prevent blood vessel constriction (angiotensin-converting enzyme inhibitors). However, these have not been consistently effective in treating cats with this disease, and their use is only appropriate in certain cases. Your veterinarian will tailor a treatment specifically for your cat.


  • Go to your veterinarian or the local veterinary emergency clinic immediately if your cat has difficulty breathing (labored, rapid, or open-mouth breathing) and/or a sudden onset of weakness or inability to use one or more legs, as these symptoms may be caused by several potentially serious disorders, one of which is hypertrophic cardiomyopathy.
  • Realize that hypertrophic cardiomyopathy has an extremely wide range of extent, and the statements described above are generalities. Having additional information, like information obtained through the tests described above, enables your veterinarian to answer questions regarding “impostor” diseases (masquerading as hypertrophic cardiomyopathy but actually different), possible treatments, and an outlook on life span and possible complications.
  • Remember that symptoms (heart murmur, labored breathing, etc.)are only clues that might indicate hypertrophic cardiomyopathy. They might also indicate any of several other kinds of very different lung, bronchial, bloodstream, or heart valve diseases. Therefore, the recommended testing is meant to confirm the diagnosis for accurate treatment and prognosis (assessing the likely outcome).•Inform your veterinarian if your cat has ever been diagnosed with a medical condition and is taking medication, since this can influence the treatment plan. For example, medications with additive effects may be beneficial or harmful depending on the circumstances, so your veterinarian needs to know what your cat is receiving (including supplements and alternative therapies).•Give medication exactly as directed by your veterinarian, and if you are concerned about possible negative effects, discuss them with your veterinarian immediately rather than simply discontinuing the treatment.
  • Take advantage of second opinions. Veterinary cardiologists exist in many large cities and veterinary schools and are known as Diplomates of the American College of Veterinary Internal Medicine (Specialty of Cardiology). Directories: or in North America and www.ecvim-ca.orgin Europe.


  • Do not postpone visiting your veterinarian if you observe any symptoms that are compatible with hypertrophic cardiomyopathy. Prompt diagnosis and treatment can be lifesaving.
  • Do not give medication that you have at home that has been prescribed for human use; some of these may interfere with treatment or cause even more severe problems.
  • Do not assume that having hypertrophic cardiomyopathy means your cat’s life span or quality of life will be compromised. Hypertrophic cardiomyopathy may be a serious heart problem in some cases, but in some cases the disease remains stable for years.


If your cat is open-mouth breathing. Remember that dogs often pant to control their body temperature, but panting is not normal in a resting cat (emotional panting, such as during a car ride, is an exception). Rather, panting in a cat indicates severe shortness of breath and requires evaluation, even if it disappears on its own in a few minutes.

  • If your cat’s appetite declines; loss of appetite in cats can cause other, severe complications.
  • If you cannot keep a scheduled appointment.
  • If you are unable to give medication as directed


  • Watch for general signs of illness, which include vomiting, diarrhea, decreased appetite, and changes in behavior such as lethargy/sluggishness or hiding more than usual. These can occur as part of hypertrophic cardiomyopathy, or as part of an unrelated disorder. Regardless of the cause, if these or other symptoms seem out of the ordinary for your cat, you should contact your veterinarian to determine whether a recheck visit is warranted.
  • Watch for signs of hypertrophic cardiomyopathy, which include weakness, inactivity, difficulty breathing (dyspnea), rapid breathing(tachypnea), and sudden inability to use a forelimb (front leg) or one or both hindlimbs (back legs).


  • Hypertrophic cardiomyopathy may deteriorate to a severe, life-threatening disease. Follow-up appointments are important to monitor progress and to determine if treatment should be adjusted. The interval at which those appointments are necessary is different with each case and needs to be discussed with your veterinarian.

From Cohn and Côté: Clinical Veterinary Advisor, 4th edition. Copyright © 2020 by Elsevier Inc. All rights reserve



Hepatic lipidosis is a very serious but potentially curable liver disease of cats. This disease occurs most commonly in cats that are overweight to obese and have undergone a period of abruptly decreased appetite (inappetence) or excessively rapid weight loss. In the healthy cat, the liver performs many functions that are critical to life. These functions include making, breaking down, and temporarily storing fats. If the cat does not eat for a period of time, fat that is stored elsewhere in the body is moved to the liver where it is broken down or metabolized into energy that the body uses as fuel. However, the liver can become overwhelmed by the amount of fat that it suddenly receives from the rest of the body. If this happens, fat accumulates in the liver and interferes with many other functions that the liver is required to perform to keep a cat healthy.

Causes: There are many reasons why cats lose their appetite with no apparent underlying illness. Any change in the cat’s environment such as a diet change, the presence of new pets in the household, or moving to a new house or apartment can negatively affect a cat’s food intake. Situations that may not seem stressful to people can actually be very stressful for cats, and many cats respond by not eating. Some diseases can predispose or occur at the same time as hepatic lipidosis and cause a sense of nausea or unwillingness to eat; they include intestinal diseases such as inflammatory bowel disease, various types of heart disease, constipation, diabetes mellitus, and pancreatitis. Cats that consume diets deficient in certain building blocks of proteins (amino acids) may be at risk of developing hepatic lipidosis. In many cases, the specific cause of hepatic lipidosis in an individual cat is never known.

Symptoms: Outward symptoms (clinical signs) of hepatic lipidosis are often not very specific and simply reflect a cat that is not feeling well. These symptoms may include weakness, decreased alertness or hiding, a new onset of vomiting, excessive drooling/hypersalivation, and a yellow tinge to the skin and/or the white of the eye (icterus/jaundice).

Diagnosis: To help your veterinarian determine if your cat has hepatic lipidosis, it is important to for you to provide what you know of your cat’s recent medical and environmental history, including diet, any changes in the household, periods of loss of appetite, and if your cat has ever been diagnosed with another medical problem or is taking medications. Your veterinarian will likely need to perform tests, since the initial symptoms of hepatic lipidosis are nonspecific and may easily be confused with symptoms of other, completely different problems. A blood sample is usually drawn to assess how the liver and other organs are functioning, and to help pinpoint the liver as the source of the problem. X-rays of the abdomen (belly) often are needed to screen for abnormalities that could influence the liver and contribute to its malfunction. An ultrasound examination may be performed since it is the test of choice for looking within the liver tissue. An ultrasound exam of the liver in a cat is exactly the same as a sonogram (ultrasound) for a person, except that a cat’s hair usually needs to be shaved from the abdomen for clearer ultrasound images. Together, these tests help to pinpoint the liver as the source of the problem, or identify impostor diseases and avoid the wrong treatment if in fact the cat has a disease other than hepatic lipidosis. The definitive diagnosis of hepatic lipidosis requires a small needle aspirate or biopsy sample of liver tissue (which in some cats require general anesthesia). Biopsy samples can be obtained via abdominal surgery—an operation—or using minimally invasive methods: ultrasound-guided core biopsy, or using a camera and small openings into the abdominal cavity—laparoscopy. Depending on the extent of the required liver specimen, cats may comfortably undergo the procedure awake (if just a fine-needle aspiration is sufficient) or may require anesthesia if a true solid tissue biopsy is required. The decision about which type of procedure is best varies from case to case and is made based on the information derived up to that point; generally a biopsy is preferred but very ill cats who are poor anesthetic candidates may only tolerate a fine-needle aspirate, for example. Some cats with hepatic lipidosis are too unstable to undergo liver sampling, and the diagnosis may be suspected based on the blood tests and ultrasound exam findings.


Hepatic lipidosis can become life-threatening if left untreated. There-fore, initial treatment usually involves intensive care. It is common for hepatic lipidosis to take several days of treatment before it is clear whether the situation is improving or deteriorating, and even then, a hospital stay of several more days is commonly necessary before a cat is self-sufficient and able to go home. Discharge to home care is sometimes possible after several days if close attention and treatment can be provided in the home, but even under the best circumstances, hepatic lipidosis is a disease that requires extensive and intensive initial treatment (hospitalization for 3 to 6 days is typical). For this reason, your veterinarian may want to discuss with you whether a second opinion with a veterinary internal medicine specialist is desirable, and may refer you to a board-certified small animal internist for that reason (directories: or [North America] and [Europe]).If the cat responds well to treatment and hepatic lipidosis is cured, it does not commonly recur. The exception is if there is persistent obesity or other unrelated illnesses that can flare up and trigger periods of appetite loss, initiating hepatic lipidosis once again. There are no known long-term adverse effects of hepatic lipidosis after it is treated successfully.


Hepatic lipidosis is a potentially critical illness that often requires intensive care and good nutrition (not too little, not too much) as the cornerstones of immediate treatment. Unfortunately, liver diseases in general often make cats unwilling to eat, and failure to eat causes hepatic lipidosis to worsen. The goal of treatment is to put the cat in a positive calorie balance (meaning it is consuming more calories than it is burning). Occasionally, cats that are still eating even a small amount may respond to appetite-stimulant medications, feeding tubes placed through the nose, warming of the food, coaxing, and other measures to encourage appetite. These measures make it possible to avoid placing a feeding tube and are worth trying only in cats with very mild cases of hepatic lipidosis. However, most cats require the placement of a temporary feeding tube as a way of allowing the cat to maintain a positive calorie balance, thus allowing the cat to regain strength and overcome the disease. This allows both food and medications to be given without handling the cat’s head and mouth and force feeding, which many sick cats resent and which can trigger nausea. Such feeding tubes are temporary; they can be left in place for a few days, or as long as several weeks, as needed.

A cat with hepatic lipidosis is treated by giving complete nutritional support, minimizing stress, treating complications if they occur (such as vomiting), and treating the underlying cause if it is known. An intravenous (IV) catheter may need to be placed to provide fluids and give medications in the hospital because most cats with hepatic lipidosis are dehydrated when first evaluated.

A cat that is hospitalized for treatment of hepatic lipidosis can go home when he or she is tolerating the tube feedings, especially if you or the cat’s caretaker can continue to feed through the tube at home. The presence of the feeding tube will not discourage the cat eating on its own. As appetite returns, most cats may eat a bit and receive the rest of the day’s calories by tube feeding, with an increasing proportion of natural eating over time. Gradually, the amount of food given by mouth is increased as the amount of food given through the tube is decreased. The great majority of cats tolerate being fed through a tube very well at home.The tube is left in place until the cat’s appetite is completely normal, which in most cases varies between 3 to 6 weeks. Removal of the tube is possible when the cat’s condition is mostly or entirely back to normal and the veterinarian feels that the risk of relapse is very low. Overall, hepatic lipidosis is a disease of cats that can be mild, but often is severe, and requires significant emotional, financial, and logistical resources: when severe, it is a high-maintenance disorder, but with a good response to treatment a full recovery is possible.


  • Give medication exactly as directed.
  • If you are feeding your cat through a tube, follow your veterinarian’s instructions closely and stop if your cat begins to vomit.
  • For all cats (not just those with hepatic lipidosis): help to prevent the occurrence of hepatic lipidosis by monitoring your cat’s weight closely; obesity plays a major role in the development of hepatic lipidosis and many other diseases. Obesity needs to be avoided to reduce the risk of this potentially very serious liver disease.
  • Understand that food consumption and hepatic lipidosis are interrelated on two different levels: first, a cat should not go without eating. But second, a cat that eats constantly can gain too much weight, predisposing to hepatic lipidosis if food consumption stops for 24 hours or more. Therefore, consider your cat’s specific situation. If your cat has just been diagnosed with hepatic lipidosis, make sure the appetite is as good as possible by feeding what he/she likes. The weight loss can begin once the condition is completely resolved and appetite is back to normal. When the appetite is back to normal and the hepatic lipidosis is resolved, then you can help to prevent hepatic lipidosis from happening again by consulting with your veterinarian about feeding weight loss/optimal weight maintenance diets long-term. These diets reduce weight, and therefore reduce the risk of hepatic lipidosis, because they are usually high in fiber and therefore likely to leave a cat feeling more full than just cutting back on the amount of regular food.


  • Do not start your cat on a diet before talking to your veterinarian, as some cats are finicky eaters and stopping eating altogether can trigger hepatic lipidosis.
  • If ANY cat has not eaten for 24 hours or more (even if he/she has never been diagnosed with a liver problem before), do not wait longer before seeking veterinary attention. Regardless of the underlying cause, the simple act of not eating for more than a day may initiate hepatic lipidosis in cats.


  • If you cannot keep a scheduled appointment.
  • If your cat will not eat or has not eaten for any period of time, particularly if your cat is overweight.
  • When treating hepatic lipidosis at home: if you encounter any difficulty giving food through the feeding tube or if your cat shows any of the signs listed below.


Weakness, decreased appetite, vomiting, diarrhea, constipation, abnormal behavior (especially hiding more than usual), excessive drooling/hypersalivation, or a disoriented, “drunken” appearance. These signs can be compatible with liver dysfunction and would warrant a recheck visit with your veterinarian to reassess and adjust medications if necessary.


  • For checking body weight, physical examination, and blood test values: initially within a week of discharge, but thereafter depends on progress and presence or absence of ongoing symptoms.

From Cohn and Côté: Clinical Veterinary Advisor, 4th edition. Copyright © 2020 by Elsevier Inc. All rights reserved.


Feline urinary syndrome (FUS), feline idiopathic cystitis (FIC), and feline lower urinary tract signs or disease (FLUTS/D) are interchangeable names given to the same cluster of urination-related symptoms that cats often display when they experience bladder problems. These symptoms include straining to urinate, frequent urination, bloody urination, urinating outside the litter box, pain while urinating, and urinating small volumes frequently. The unifying theme in these syndromes is that there is no infection, no bladder stone, no behavioral cause, and no identifiable defect in the urinary system. In other words, FLUTS/D is a disorder of inflammation and pain that makes urination uncomfortable for cats but that has no recognizable cause. It is a very common problem in cats.

A cat is known to have this disease when he/she shows some or all of the symptoms described above in the absence of all other urinary disease processes. Therefore, a series of tests is always necessary to try to identify other problems, such as a bladder infection or bladder stone, which might cause symptoms similar to FLUTS/D but which would require specific treatment (certain antibiotics, or stone-dissolving medications or diets, or even surgery) to alleviate an identifiable problem. Tests that are used for assessing urinary problems in cats include a complete blood panel, urinalysis, x-rays, urine culture, and abdominal ultrasound. When a cat has symptoms of urinary difficulty and these tests produce normal results, then FLUTS/D is considered to be the cause. The characteristic problem of FLUTS/D is inflammation of the urinary bladder (cystitis). The protective mucous layer that lines the inside of the urinary bladder is deficient in cats with FLUTS/D, which allows the harsh chemicals of the urine to contact the deeper tissues of the bladder, causing irritation of the bladder wall.

While much is known about the symptoms and characteristics of cats with FLUTS/D, the exact cause of the disorder remains unknown. In this manner, FLUTS/D is almost identical to a similar urinary syndrome, interstitial cystitis, which occurs in humans, especially middle-aged women.

In some cats, the diagnosis of FLUTS/D may be unclear. A good source for a second opinion is an internal medicine specialist veterinarian (directories: or[North America]; [Europe]) and you should speak with your veterinarian about seeing one of these specialists as necessary.


First and foremost, it is essential to determine if a cat with these symptoms has an identifiable and treatable disease that can be eliminated using appropriate therapy (antibiotics for a bacterial infection, diet therapy or surgical removal for stones, etc.). This requires the tests described above. Without these tests, inappropriate medications and unsuccessful outcomes (symptoms persist or worsen, adverse reactions to medications) are common.

Second, if the tests are negative, as expected for FLUTS/D, other potential causes of inappropriate urination can be eliminated from suspicion. A simple and vital preventative step you can take is to make sure that the household has several litter boxes (one for each cat, plus one additional box) and that they are entirely cleaned daily. It can be useful to observe your cat urinate to make sure the cat squats (not standing and marking vertical surfaces) and to observe the volume of urination. Is the puddle the size of a quarter? Is it like a cup of water spilled? This information will be extremely useful to the veterinarian in assessing the possibility of FLUTS/D. Third, a factor that is known to trigger or worsen FLUTS/D is stress. This may be identifiable (construction in the home, recent move, a new baby, puppy, or kitten in the home), or it may be more subtle. Indoor-only cats especially can become bored, and there is stress associated with that. Reducing and removing stress when possible will often help or even eliminate symptoms of FLUTS/D. Finally, if the stress initiator cannot realistically be removed or addressed, then there are some medications that may be beneficial.

Often symptoms will resolve on their own within a few weeks, independent of any medication or changes in the home. The difficult problem is that symptoms often come back. Some cats can have a bout of FLUTS/D that lasts a couple of weeks and resolves on its own without treatment and never have a problem again. Other cats with FLUTS/D develop symptoms every couple of months and have problems for weeks on end each time. Your cat may be on either end of this spectrum of severity or somewhere in the middle.


Increase water intake. Ways of encouraging cats to take in more water include: providing plenty of clean and fresh water sources; making sure that bowls are cleaned regularly and water is changed frequently (at least twice daily); providing wet (canned) cat foods; and providing a source of moving water (purpose-made cat water fountains or just leaving a faucet that is accessible to the cat to drip several drops per minute). The goal behind increasing water intake is to dilute the urine, which is less irritating to the inner lining of the bladder surface.

Psychological therapy involves identifying and reducing or removing stressors in the environment. Separating cats into different rooms of the home can be useful if the cats have a tendency to fight or don’t seem to get along. Providing a perch near a closed window so a cat can be distracted by the outdoors also can be helpful. Provide lots of toys or climbing perches. Your veterinarian can provide additional information on important and simple techniques for environmental enrichment that may be as effective or more so than medications. An excellent source of information is a veterinary website dedicated to this issue: or pheromone therapy has been suggested and recommended by many veterinarians. There are several over-the-counter (nonprescription) products that are claimed to provide calming hormonal stimulation. Few if any of these has been scientifically tested. There are many people who subjectively feel these provide significant benefit.

Glucosamine and chondroitin supplements are used for treatment of arthritis by many veterinarians and physicians. It has been theorized that there may be benefits to an inflamed bladder if a cat is given a glucosamine and chondroitin supplement. This is because the mucous layer of the bladder lining and the protective fluid of the joints are very similar chemically. Many glucosamine and chondroitin supplements have been shown to be nontoxic and have few side effects, but their benefits are unclear and still somewhat controversial. Use of glucosamine and chondroitin therapy in cats with FLUTS/D shows some promise, but it is not a wholly curative therapy.

Nonsteroidal anti inflammatory drugs have been theorized to aid in cats with FLUTS/D by directly reducing the inflammation of the bladder and/or providing pain relief. A very limited number of these drugs is tolerated well by cats, essentially all by veterinary prescription only.

Be careful to NEVER give an antiinflammatory pill or syrup to a cat if it is a human medication; many of these are toxic to cats and have been fatal with just one dose. Even prescription nonsteroidal antiinflammatory medications designed for cats may cause adverse side effects including gastrointestinal irritation, gastric ulceration, and kidney damage. These medications should be administered only after consulting with your veterinarian, at appropriate doses, and with frequent recheck to monitor for signs of adverse side effects.

Opioid drugs are prescription analgesics (painkillers) that have been used for breaking the “pain cycle” of bladder irritation and to provide relief from symptoms. These drugs are often difficult to prescribe and administer outside a hospital setting, so they are reserved for cats whose pain level is so high that they require hospitalization. These drugs also can have significant side effects and the hospitalization should include patient monitoring for these effects.

Antianxiety and psychotropic drugs are available for cats, and these also have shown some promise for treating FLUTS/D. While few if any of these have been appropriately scientifically tested, they seem to help individual cats and can be considered in difficult or persistent, recurrent cases.


  • Test for—and eliminate the possibility of—different urinary diseases that could produce symptoms that mimic FLUTS/D but actually are entirely different and require completely different types of treatments.
  • Try to make realistic and reasonable adjustments to your household to reduce stress.
  • Provide plenty of clean litter boxes.
  • Try to increase water intake, provide clean fresh water, and wet cat foods.
  • Consider trying over-the-counter “de-stress” hormones orpheromones as part of the treatment plan.
  • •Consider glucosamine and chondroitin supplementation. Cats only need a small amount; consult your veterinarian for appropriate dosages. This can often be sprinkled on food, which means there is no need to administer a pill.
  • Consider nonsteroidal antiinflammatory or opioid therapy; these should be done under the guidance of your veterinarian for extreme cases. Follow-up monitoring is important with these drugs.


  • Don’t give up. Often, symptoms resolve on their own and may never come back. Give your cat some time to heal.


  • Recurrence of symptoms.
  • If symptoms change (urinating larger volumes, foul-smelling urine, worsening signs of pain, etc.).
  • Signs of secondary side effects of medications including poor appetite, vomiting, diarrhea, and lethargy.


Your veterinarian may ask you certain questions about what you see your cat do. Knowing the answer to these questions can be very helpful in determining the severity of FLUTS/D, or even whether an alternate cause is the problem instead.

  • How is your cat actually urinating? Squatting or standing? Small amounts or large? Blood? Odor worse than normal?
  • Where is the cat urinating? On the bed? In the laundry, etc.? In one particular place or all over the home?
  • When is the cat urinating? When you have guests? During the day or at night, etc.? This information can help with the initial diagnosis and, of course, is useful for monitoring how the problem is evolving—deteriorating or improving.


  • •Follow-up should be tailored to the specifics of each cat. Some cats will need more frequent rechecks (for example, if taking daily medications). Others will respond quickly and will need few if any rechecks. Your veterinarian can provide guidelines for rechecks that are appropriate for your individual cat.

From Cohn and Côté: Clinical Veterinary Advisor, 4th edition. Copyright © 2020 by Elsevier Inc. All rights reserved.



Feline leukemia virus (FeLV) is a virus that can infect cats. It was first discovered in cats that had leukemia, which is a cancer of circulating blood cells. Nowadays, we know that this virus does cause leukemia—one of the few known infections that can lead a cat to develop cancer—but most cats with feline leukemia virus are asymptomatic. This asymptomatic state usually lasts for weeks to years until cats begin to show vague symptoms due to anemia, a weakened immune system that allows for other infections, or leukemia.

The virus acts by entering the cells in a cat’s tissues throughout the body and “taking control” of the process that cells use for replicating themselves. In this way, the virus guarantees that it will survive in future generations of cells and spreads throughout the body. Some cats exposed to feline leukemia virus infection are able to fight it off and remain healthy for their entire lives. Others bring the virus under control and might never have any health problems as a result, although they do continue to be infected. Other cats can develop very serious, life-threatening diseases as a result of the feline leukemia virus infection; these include some types of cancer, bone marrow suppression, and immune deficiencies (weakened immune system).Feline leukemia virus can be transmitted among cats in close, prolonged contact with each other through saliva, urine, and other bodily fluids including nasal and eye secretions. Often, it is transmitted from a mother cat to her kittens, and kittens are less able to fight off the virus than are adult cats. It is uncommon for a one-time exposure to lead to infection; rather, repeated exposure such as living together in a household or colony (for instance, barn cats) contribute to the spread of this virus between cats. Unneutered male cats that wander and fight have an increased risk of becoming infected and of transmitting the disease to other cats because of this behavior.

Feline leukemia virus can be transmitted from an infected pregnant cat to her unborn kitten (fetus) or to her newborn kitten in her milk or through maternal grooming of the newborn. Infected fetuses may die in the uterus, such that a cat’s owner may never know that the cat was pregnant. The infected fetus may be aborted or the newborn infected kitten may die shortly after birth. Some kittens that are born with feline leukemia virus survive to become adults but have intermittent illness during their lives (persistently infected adults).Many infected cats do not show signs (asymptomatic) of infection outwardly; however, they can still pass the infection on to other cats. Infected cats that do show signs of illness (clinical signs, symptoms) may have weight loss, weakness, fever, dehydration, inflammation of the lining of the nasal passages (rhinitis) causing nasal congestion and discharge, diarrhea, red eyes (conjunctivitis), sores in the mouth, enlarged lymph nodes, and/or abscesses under the skin. Anemia (decreased number of red blood cells) in cats is commonly caused by FeLV. Because this virus also infects white blood cells, the immune system commonly is weakened. As a result, cats infected with FeLV are susceptible to infections with other organisms (secondary infections) such as bacteria, other viruses, protozoa, and fungi that in turn can lead to other symptoms, including respiratory and intestinal problems. All the symptoms of FeLV infection are vague, and no symptom is truly characteristic of feline leukemia virus infection alone. Therefore, the suspicion of feline leukemia virus infection arises in two contexts: either one or more of these symptoms is/are noted by the veterinarian, or feline leukemia needs to be checked for as part of a routine health screen, such as when adopting a new cat or evaluating a cat’s other health issues. When feline leukemia is suspected by a veterinarian, the next step is to perform a feline leukemia blood test.

There are several blood tests currently used for establishing the diagnosis of feline leukemia virus infection. A screening test (enzyme-linked immunosorbent assay, ELISA) is always used first. For this test, a small blood sample is drawn and screened for the virus. Results can be obtained in a few minutes, and a negative result is highly reliable (true negative; >99% likelihood that the cat does not have feline leukemia virus). If the screening test is positive, a confirmatory test (immunofluorescent antibody, IFA; or polymerase chain reaction, PCR) is necessary because false positives do occur. The confirmatory test is also done on a blood sample, but it must be sent out to a lab and the results take a day or more to be available.

There are many factors to consider when interpreting the results of these tests. For example, early in the disease, the screening test may be negative when, in fact, the cat has the virus but the number of virus particles is too low to be detected in the bloodstream. For this reason, if a cat with symptoms consistent with FeLV has negative test results, some veterinarians will repeat the test one to several months later, or the test may be repeated if a kitten was recently adopted. The cat’s lifestyle must be considered when interpreting results of tests. Cats that roam or have been exposed to other cats that are known to have the disease are at a higher risk of testing positive for this virus, and repeated testing is more likely to be necessary in such cases. There are other issues associated with test interpretation, and no test is perfect.

Because there is no medication that will eliminate feline leukemia virus once a cat is infected, prevention of contagion through environmental control (indoor-only lifestyle, avoidance of contact with cats of unknown or positive feline leukemia virus status) and vaccination are extremely important.

This virus is not known to infect people; however, cats with this disease may harbor other infectious agents that can be spread to humans. This is especially worrisome for people with weakened immune systems (such as individuals with HIV/AIDS, people under-going chemotherapy treatments, etc.). Therefore, cats with feline leukemia infection should be monitored closely for any symptoms of illness and should be brought to a veterinarian to be evaluated promptly if symptoms of any sort of illness become apparent, both for the cat’s sake and for the benefit of any individuals in contact with them that might be prone to infections.


While it is ideal to prevent infection, cats that have already been infected can still make good pets but require some special care. Firstly, cats that are diagnosed with feline leukemia virus must be confined indoors to prevent spreading this disease to other cats in the neighborhood. This confinement also prevents the cat from contracting diseases from other cats and the environment, because of the reduced immune function caused by feline leukemia virus. Cats that have feline leukemia virus infection should be examined by their veterinarians at least every 6 months so that subtle symptoms of secondary infections, anemia, or cancer can be detected by physical examination and routine blood tests. Asymptomatic (that is, apparently healthy) cats that have the feline leukemia virus should still receive at least some routine (annual to triennial) vaccinations. Routine vaccinations help to reduce the risk of other common, serious infections, and the need for these is determined on a case-by-case basis according to exposure risk. You should discuss the advantages and drawbacks of vaccination for your feline leukemia-positive cat with your veterinarian to determine the best approach. There is a vaccine that protects against feline leukemia virus, but it should not be given to feline leukemia-positive cats because once a cat has the virus it is too late for the vaccine to help. Rather, it is appropriate to give it to feline leukemia-negative cats. It is best if infected cats can live in a one-cat household. If that is not possible, the next best thing would be to keep the infected and noninfected cats separate (separate litter box, bowls, etc.). If this is impossible, any cats that are not infected with feline leukemia virus should be vaccinated against infection. All household cats should be treated with flea and tick preventatives, and a good program of internal parasite control should be followed as well. Finally, it is very likely that even a seemingly healthy cat infected with feline leukemia virus will at some point become ill. These cats should be taken for veterinary care immediately, without waiting a few days as you might for an uninfected cat. With early treatment, many of the complications that make these cats ill can be treated. However, it is very likely that feline leukemia virus-infected cats will live a shorter life than an uninfected cat.


Pet: There is no antiviral drug that can eliminate feline leukemia virus to cure the infection. Instead, the focus is to keep asymptomatic cats healthy for as long as possible, and to quickly intervene when they do eventually become ill. This might include blood transfusions for cats that have low red blood cell counts, antibiotics for cats with bacterial infections, or chemotherapeutic drugs for cats that develop cancer. Other supportive measures may be necessary, including forced nutritional support of fluid therapy in the case of dehydration. Sometimes, treatment also includes immune modulators to try to help to strengthen a cat’s immune system – these seem to have minimal efficacy. Antiviral agents directly impair the virus to prevent it from replicating. These kinds of drugs can be both expensive and toxic in cats, and they do not cure infection. None of these treatments can completely rid your cat of the virus, but your veterinarian can tailor a treatment regimen for your pet. At some point, perhaps years down the line, the viral infection can lead to difficult to treat complications and humane euthanasia (putting to death via lethal injection) might be considered.

Environment: Fortunately, the feline leukemia virus is relatively fragile and easily destroyed by most detergents and disinfectants (for example, diluted household bleach 1 part bleach to 30 parts water). It survives for only several hours outside a cat’s body on objects such as food bowls, water bowls, and litter boxes. If you are bringing a new cat into the household after having housed a cat with feline leukemia infection, no special precautions are required if the infected cat has not been in the house for more than several days.


  • Have any new kitten or cat tested for feline leukemia virus, and if negative, vaccinated against the infection.
  • Know the feline leukemia virus status of all cats in your household. This is a cornerstone of knowing the health status of a cat. Even if your cat is kept strictly indoors, your veterinarian should recheck the status if any new illness occurs. This is because infection can be hidden for many years, and your cat might have been infected even as a young kitten.
  • Keep all feline leukemia virus-positive cats strictly isolated indoors.AT ALL TIMES to avoid contagion to other cats.
  • Understand that having feline leukemia virus does not mean a cat is suffering; some cats naturally keep the virus in check for years and have a normal quality of life, while others can become very ill soon after infection.
  • Realize that the seriousness of a cat’s feline leukemia virus infection is highly variable and that the most reliable information comes from the evaluation of your specific cat (rather than generalizations in brochures, textbook chapters, or internet sources).
  • Establish a schedule of regular visits to your veterinarian if your cat has feline leukemia virus.
  • Give medication(s) prescribed for your pet exactly as directed.
  • Contact your veterinarian immediately if you feel your cat shows negative reactions to the medication(s) or new symptoms appear that might be linked to FeLV-induced secondary disease.


  • Do not introduce new cats to cats that you already have until you are sure that the new cat has tested negative for feline leukemia virus (and you know the status of your current cats).
  • Do not assume that a cat vaccinated against feline leukemia virus cannot acquire the disease. No vaccine offers a 100% guarantee, and testing a cat is always appropriate when the cat is about to first enter the household, or when signs of illness occur that a veterinarian suspects may be due to immune deficiency, anemia, or cancer.
  • Do not allow a cat that has feline leukemia virus to roam freely outdoors.
  • Do not allow a cat that has feline leukemia virus to eat uncooked meat (risk of toxoplasmosis).•Do not neglect preventive care for a feline leukemia-infected cat.
  • Do not ignore any sign of illness in a feline leukemia-infected cat; instead, seek prompt veterinary evaluation.


With your cat that has had a feline leukemia virus-positive test:

  • If your cat shows negative reactions to the medication(s).
  • If you cannot return for a scheduled visit.
  • If your cat has lost weight, decreased appetite, weakness, been bitten by another cat, diarrhea, sores in the mouth, or abscesses(lumps under the skin), or any other sign of illness.

With any cat:

  • If your cat has been exposed to a cat with an unknown or positive FeLV status.


  • When giving medication, watch for sluggishness, weakness, decreased appetite, hives (bumps under the skin), vomiting, diarrhea, or any abnormal behavior as general signs of either intolerance to the medication or worsening of the disease; are check visit to the veterinarian may be needed to tell the difference between the two

From Cohn and Côté: Clinical Veterinary Advisor, 4th edition. Copyright © 2020 by Elsevier Inc. All rights reserved.



Feline infectious peritonitis (FIP) is an extremely serious viral disease that affects cats but not dogs, humans, or any other species. It is caused by a coronavirus, meaning that it is spread mainly through the digestive tract, and is contracted by cats when they are in contact with the feces (stool, excrement) or bodily fluids of infected cats. FIP is usually rapidly fatal in cats, so identification of infected cats is important.

There are many coronaviruses that infect the gastrointestinal tracts of different animals, and they fall into two broad categories: enteric coronaviruses, which cause mild, brief signs of digestive upset and are relatively harmless, and mutated coronaviruses such as the FIP virus. An example in the first category, feline enteric coronavirus, is a virus that is commonly found in cats, is restricted to the gastrointestinal tract, and does not cause significant illness at all. By contrast, some variants, or strains, of this virus, such as feline infectious peritonitis virus, fall into the second category, do cause significant illness, and are responsible for FIP. These viral variants are able to travel out of the digestive tract, through the bloodstream, to other parts of the body where they may persist indefinitely and cause severe symptoms that can become life-threatening.

FIP is a disease that most frequently appears in young cats less than 2 years old but can occur in cats of any age. Almost any part of the body may be affected by the spread of the FIP virus, including the liver, kidneys, lungs, nervous system (brain and spinal cord), and eyes.

While coronaviruses in general are highly contagious, the number of exposed cats that actually contract FIP is low. In most cats, coronaviruses remain confined to the intestinal tract and will not cause FIP. It appears that a combination of virus mutation and a trigger within the cat (possibly with an underlying genetic component) cause otherwise harmless enteric coronaviruses to transform into FIP virus. It is of critical importance to realize that because of this, testing cats for exposure to coronaviruses is of no use in identifying FIP, because a large proportion of the feline population has enteric coronaviruses with no adverse consequences. Once a cat has been confirmed to have FIP (which requires analysis of fluid and/or tissue- see below), the possibility of contagion is very low since the virus is no longer in the gastrointestinal tract and thus is not shed in the feces. Nevertheless, there is some small degree of risk and precautions such as separation of an infected cat from other cats, and basic hygiene including handwashing and litter box hygiene, are recommended.

Affected kittens may have stunted growth and fail to thrive. They will often be thin and have a rough, dull haircoat. Although there is significant overlap, a simplistic way to look at infection is that there are two different sub forms of FIP, a “wet” and a “dry” form. The “wet” form causes fluid accumulation in the abdomen (belly) or the chest; abdominal fluid accumulation can give a potbellied appearance that is often mistaken for intestinal parasites, whereas fluid accumulation in the chest may cause difficulty breathing due to fluid compression of the lungs. Cats with the “dry” form of FIP may slowly lose weight and have appetite loss, lethargy, and unexplained fever. The onset of disease is usually very gradual with the dry form. Older cats almost always contract the dry form of FIP. This form of FIP can also cause a variety of nervous system symptoms, including seizures or blindness. In reality, a single cat can have manifestations of both wet and dry forms.

The diagnosis of FIP is complicated by the fact that blood tests cannot distinguish between harmless, nonpathogenic feline enteric coronaviruses and the devastating strains that cause FIP. Often, suspicion is based on history (for instance, kittens obtained from animal shelters or catteries are often exposed to the coronavirus), clinical signs, and physical examination. Other tests, including blood tests and imaging tests (x-rays or ultrasound) can lend support, as can analysis of any abnormal fluid in the chest or abdomen. Often, for the wet form of FIP, these tests are enough to feel confident in the diagnosis. However, positive diagnosis of the dry form of FIP can be a challenge. If there is a high suspicion that dry FIP is responsible for a cat’s symptoms, surgery is often required to obtain biopsy samples from various organs. Tests (immunohistochemistry) performed on the biopsy samples can confirm the diagnosis, and tissue biopsy, typically of the intestine, is the gold standard for diagnosis of FIP if any uncertainty remains from the results of less invasive tests.


If your cat is diagnosed with FIP, you should prevent his/her coming in contact with new cats since the virus is potentially contagious. However, there is no need to isolate him or her from other cats in the household with which he or she has already been in contact. All of the household cats are likely to have already been exposed to the virus, so isolation will not prevent spread of the virus and may, in fact, have a negative impact on the health of the cats due to the additional stress it causes. Most cats exposed to the virus will not develop FIP.


There is no cure for FIP, and symptoms tend to worsen over days to weeks (sometimes months) until fatal. Therefore, treatment of FIP is aimed at making an affected cat comfortable. The cat should be encouraged to eat, and stress should be avoided. Treatments with immunosuppressive drugs, such as corticosteroids, or immunomodulators are often used, but the benefits are limited. FIP is devastating and virtually every cat with confirmed FIP dies of the disease, although some can live for several months with supportive treatment. Many cat owners make the difficult but reasonable choice to have an affected cat or kitten euthanized (killed by humane lethal injection) after the diagnosis is established.


  • •Be sure that the diagnosis is accurate since FIP is devastating, and false results (false positive or false negative) are common. Specialists in veterinary internal medicine, who are experts in current diagnosis and treatment of this type of illness, are known as Diplomates of the American or European College of Veterinary Internal Medicine. They can provide a very helpful second opinion, since symptoms of FIP can be imitated by so many other, unrelated disorders. They may also be aware of new treatment opportunities as this disease remains under investigation, with some promising results recently reported. These specialists can be found in most large North American and European cities (directories: or for North America; for Europe).
  • If the diagnosis of FIP is confirmed and your cat is showing symptoms of illness such as loss of appetite, tempt your cat to eat with his or her favorite foods.
  • Avoid stressful situations for the cat (unnecessary transport, extremes of temperature, etc.), which can allow the disease to worsen.
  • Consult your veterinarian for information on other supportive treatments that may be appropriate.


• Do not allow your cat to roam outdoors or otherwise have contact with uninfected cats, to help prevent spread of the virus.


When treating a cat that has had FIP confirmed:

  • If your cat will not eat or drink or becomes extremely debilitated.
  • If your cat develops rapid, shallow breathing or begins to breathe through its mouth (panting like a dog), which is abnormal in cats (exceptions: when traveling or when the weather is hot, in which case even healthy cats may pant).


As signs warranting an immediate recheck, including after hours/emergency:

  • Rapid, difficult breathing or open-mouth breathing. This can be a sign of fluid buildup around the lungs and is an emergency. Be careful to not stress your cat if it shows these signs, but rather telephone the veterinary hospital and proceed calmly.


  • Cats diagnosed with FIP usually live in, or have originated from, multiple-cat households (more than five cats) or breeding catteries. Breeders and owners of multiple cats should consult their veterinarian for more information on the control of FIP in these situations.
  • A vaccine is available for FIP. However, it is not generally recommended for household cats and has not proved to be very effective in preventing the disease.

From Cohn and Côté: Clinical Veterinary Advisor, 4th edition. Copyright © 2020 by Elsevier Inc. All rights reserved.


Feline immunodeficiency virus (FIV) can cause an irreversible infection in cats. Although FIV is similar to human immunodeficiency virus (HIV) that causes acquired immune deficiency syndrome (AIDS) in people, FIV cannot be transmitted to people, and cats cannot carry HIV. However, cats with FIV may have immune deficiencies that eventually make the cats vulnerable to the same secondary diseases that people with depressed immune systems can acquire (for example, chronic diarrhea or respiratory or skin problems that people with HIV/AIDS or individuals undergoing chemotherapy treatments can have). A retrovirus, like FIV, is an organism that survives by invading the animal’s healthy cells and “taking control” of the mechanism that the cells use to replicate. In this way, the virus guarantees that it will be present in future generations of the cells throughout the body.

FIV is spread from cat to cat, primarily through bite wounds from infected cats. Unneutered, adult male cats that roam outside are most commonly infected with this virus; however, any cat can acquire this disease. The disease is also rarely transmitted from an infected mother cat to her nursing kitten in the milk. Sexual transmission is very uncommon, in contrast to HIV.

The FIV virus can cause damage in two ways. It can weaken a cat’s immune system (immunosuppression) and make the cat susceptible to other infectious organisms such as bacteria, other viruses, yeast, fungi, etc. (secondary or “opportunistic” infections). A virus can also directly destroy healthy cells so that they no longer function properly. Initially, for a few weeks after infection as the virus is spreading through the body, a cat may have a low-grade fever, enlarged lymph nodes, or other vague signs of illness that may never be detected. After this period, the virus generally goes into a latent stage during which time the cat can appear healthy; however, the virus continues to work in the two ways described above during this latent period. This latent stage can last for many years before the cat shows any outward signs of illness (clinical signs or symptoms). Symptoms, if they eventually occur, may include skin and ear infections, diarrhea, anemia (a decreased number of red blood cells), redness and inflammation of the gums causing decreased appetite and/or tooth loss, respiratory problems including pneumonia, abnormal urination, abnormal behavior such as roaming and confusion or dementia, and certain types of cancer. These symptoms depend upon which cells the virus “chose” to infect, and are often nonspecific. That is, these kinds of symptoms are vague, and may be caused instead by any of a number of disorders that are completely unrelated to FIV. The presence of such symptoms, particularly in cats that roam or have been strays in the past (and therefore may have been exposed through bites from other cats) leads a veterinarian to want to test a cat for FIV, to confirm or eliminate FIV as a cause of the symptoms.

A blood test (ELISA test) is commonly performed to detect this disease. The test involves placing a small sample of your cat’s blood on an FIV test cartridge and having results in a few minutes. It is a good screening test, although no test is 100% reliable. For example, previous vaccination for FIV can make the result of the test positive even in the absence of actual FIV infection. Similarly, kittens younger than 6 months can test positive not because they are infected, but because they acquired antibodies to the infection from their mother’s milk. There are many factors that must be considered when interpreting test results, and if any discrepancy arises, your veterinarian may choose to repeat the test at a later date and/or send a blood sample to a laboratory where another test may be done to help confirm a diagnosis.


Cats that have FIV must be kept indoors and isolated from other cats. Isolation is important to prevent a cat from transmitting FIV to other cats and to prevent the infected cat (with a weakened immune system) from contracting diseases from other cats in the neighborhood. FIV-positive cats should be neutered to decrease the tendency to roam and fight. Proper nutrition is extremely important to help an affected cat remain as healthy as possible.

The latent period may last for many years in FIV-positive cats, and a positive test result in a cat that is otherwise feeling well does not imply suffering of any kind or any other immediate health problem. During this time, a cat usually is entirely comfortable and happy. Other cats should not be brought into the household and exposed to this cat (to prevent spreading of FIV), especially if the FIV-positive cat is resentful or aggressive toward other cat(s).

There is a vaccine available for FIV, but this is not considered a routine vaccine. It does nothing to treat infection once it occurs. The vaccine is most suitable for uninfected cats that roam outdoors and are likely to be exposed to infection. Ask your veterinarian if this vaccine is appropriate for your cat.



For infected cats that seem well, no medications are required. However, you must be alert to any new problems that might signal a secondary infection or some other complication of the virus. When, and if, such complications arise, the problems caused by the virus are treated directly. This might include antibiotics to treat secondary bacterial infections resulting from a weakened immune system, transfusion for anemia, chemotherapy for cancer, or dental procedures for oral complications.

There is no medication designed specifically to treat cats with FIV. However, some cats have been treated with antiviral drugs designed for humans. Success has been limited using these medications. Another type of medication, immune stimulants, has been used for helping to strengthen the animal’s own immune system. Success has also been variable using this type of medication. Treatment may involve weeks of injections and/or giving the medication by mouth. No medication can completely eliminate the virus from a cat’s body.


FIV is spread most commonly through bite wounds and not through casual contact. If the virus exists on objects such as food or water bowls and litter boxes, it is easily destroyed using common household disinfectants such as diluted bleach (1 part bleach to 30 parts water). If you plan to bring a new cat into the home after the FIV cat no longer lives there, there are no special precautions to take assuming it has been more than several days since the FIV-infected cat has left the premises.


  • Know the FIV status of all cats in your household, and isolate FIV-positive cats from all other cats in the household. Have any new cat tested before bringing it into the home.
  • Keep FIV-positive cats strictly indoors.
  • Have FIV-positive cats neutered.
  • Set up a schedule of regular visits to your veterinarian so that subtle changes in your cat’s health can be detected and a treatment plan can be discussed.
  • Realize that the main reason for identifying FIV is to know if a risk of contagion to other cats exists, and to investigate persistent symptoms (intestinal, dermatologic, respiratory, neurologic) that could be caused by FIV-related opportunistic infections.
  • Give medications exactly as directed.


  • Do not assume that having FIV is a “death sentence” for a cat. Quite the opposite, most cats with FIV show no symptoms, feel well, and continue to do so for years (a normal life span with a good quality of life is possible).
  • Do not introduce cats with an FIV-positive status to cats currently in your household.
  • Do not allow FIV-positive cats to roam outdoors or to come in contact with any other cats.
  • Do not allow kittens to nurse from FIV-positive mother cats.
  • Do not assume that a cat vaccinated against FIV cannot contract this disease; no vaccine can provide 100% protection.


  • If your cat has been bitten by a cat with an unknown FIV status. An initial exam is essential, and a follow-up FIV test is warranted 2 to 3 months later (the time it takes for the body to provide the first clue of harboring the virus).
  • If you have any questions concerning the drug that you are giving your cat.
  • If you cannot keep a scheduled appointment.


As signs suggesting that an FIV-positive cat may be developing signs of an opportunistic infection:

  • If your cat shows any signs of illness, including weakness, lethargy, vomiting, diarrhea, decreased appetite, weight loss, skin and/or ear problems, abnormal urination, or any abnormal behavior.

From Cohn and Côté: Clinical Veterinary Advisor, 4th edition. Copyright © 2020 by Elsevier Inc. All rights reserved.

About CVC

Chappelle Veterinary Clinic is a full service Veterinary Clinic which offers a wide range of veterinary care for cats and dogs, including routine exams, vaccinations, preventative care, diagnostics, surgery, spay and neuter, wellness services, dental cleaning, emergency and more.

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