Feline Health Issues and Symptoms
In this article, you will find a partial list of cat illnesses, their causes, and tips on how to best prevent them. It is important to note, however, that if you think your cat is suffering from an illness, it is essential to visit the veterinarian for diagnosis and treatment.
Upper Respiratory Infection (URI)
This is one of the most common problems seen in cats and especially in kittens. Symptoms include sneezing, discharge from the eyes and/or the nose, lethargy, fever, and loss of appetite.
The risk of URI can be decreased by keeping your cat indoors and away from infected cats. Although most cats have been exposed, many are asymptomatic carriers, and viruses can be transmitted not only directly but also via hands, clothes, toys, etc. Vaccinations limit the severity of illness but may not prevent upper respiratory infections altogether. Antiviral medications are not completely effective, but in severe or chronic cases, they may reduce symptoms. Antibiotics also may be prescribed to treat secondary bacterial infections. Relief from nasal congestion is important for comfort and may require medications and/or a steam humidifier or nebulizer.
Here is an overview of the agents that may cause or contribute to upper respiratory infection in cats:
- Feline Viral Rhinotracheitis
This virus is caused by the feline herpesvirus, which only affects cats and is not contagious to humans. In addition to upper respiratory signs, this virus can cause corneal ulcers. In some cats, permanent damage may be done to the nasal passages, which may result in chronic issues such as sneezing, congestion, noisy breathing, etc. As with other herpesviruses, this infection can be life-long and signs can recur during times of stress. Vaccination is recommended.
- Feline Calicivirus
This virus can be associated with oral ulcers, gingivitis, stomatitis (inflammation of the mouth), and/or limping. Recovered cats can become carriers. In some kittens, it can lead to serious, even fatal, pneumonia. In recent years, a more virulent but much less common strain of the virus has been shown to cause extremely high fevers, facial and limb swelling, and often death, even in adult cats. Vaccination is recommended.
- Bordetella Bronchiseptica
bacterium is known as the cause of kennel cough in dogs, but it also can affect cats. Signs are generally mild, and the cat only may require supportive care or a course of antibiotics. A vaccine is available but is not considered necessary for most cats.
- Chlamydophila Felis (formerly Chlamydia Psittaci)
This bacterium can cause conjunctivitis as well as typically minor respiratory symptoms. Again, it is susceptible to antibiotics, and vaccines are available but are not considered necessary for most cats.
This bacterium may cause primary or secondary ocular and/ or respiratory signs and also can be involved in pneumonia. No vaccines are available, but Mycoplasma is susceptible to antibiotic treatment.
Feline Distemper or Panleukopenia (FPV)
This disease is caused by the feline parvovirus, which is passed in all body secretions and can live for months to years in the environment. The virus causes suppression of white blood cell production by the bone marrow, as well as ulceration of the intestines. Signs include vomiting, diarrhea, fever, decreased appetite, and dehydration. Among unvaccinated cats, it is highly contagious and often fatal, even with treatment, which usually involves hospitalization and intensive care. Kittens are particularly at risk. Vaccines are very effective and have dramatically reduced the number of cats who contract the disease.
Feline Leukemia Virus (FeLV)
This retrovirus is unrelated to human leukemia. The virus is passed between cats via saliva, usually through mutual grooming and sharing food and water dishes. It also can be transmitted to kittens before birth or via nursing. The signs vary, but FeLV can cause multiple illnesses including anemia and cancer. Affected cats also become immunosuppressed and susceptible to other infectious diseases. This disease is incurable and generally fatal, although some cats can live for years before becoming ill, especially if they receive regular veterinary care, proper nutrition, and are not subjected to a stressful lifestyle. In most cases, a simple blood test can detect FeLV infection. The preventative vaccines are very good, but they may not give your cat absolute protection. The best prevention is eliminating exposure, which means keeping cats indoors and away from any direct contact with any known FeLV positive cats. Healthy-looking cats may carry the virus and be contagious; therefore, it is important to test any new arrivals for FeLV before allowing contact with your cat.
Feline Immunodeficiency Virus (FIV)
This virus is similar to the Human Immunodeficiency Virus (HIV). Most often, FIV is transmitted through cat bites, but it also may be passed in-utero. Infected cats gradually lose their ability to resist disease but may still live long, healthy lives if kept indoors and provided with diligent veterinary care and proper nutrition. Reliable blood tests for FIV exist, but cats who have been vaccinated against FIV also will test positive, and the current commercially available tests cannot differentiate between a vaccinated cat and an infected cat. In addition to causing cats to test positive, the FIV vaccine may not protect against all strains of the virus. The best way to protect cats from FIV is to keep them indoors and to prevent fighting.
NOTE: FIV and FeLV are only contagious between cats—you can’t catch them from your pet.
Feline Infectious Peritonitis (FIP)
This disease is both frustrating and misunderstood. It is nearly always fatal and is far more common in kittens. It begins when a cat contracts the common feline coronavirus, usually through contact with infected stool (for example, through shared litter boxes). The benign coronavirus causes mild signs of intestinal upset or no signs at all. Most cats recover on their own, but in some cats the coronavirus changes, and the mutated virus then causes an immune-mediated disease called FIP. Why this happens in certain cats is unknown, but genetic predisposition and stress are likely factors in the development of the disease. There are two types of FIP. One form is the effusive (or wet) form, in which fluid builds up in body cavities, most often the abdominal cavity causing a characteristic distended abdomen. The other is the dry form where virus associated inflammatory cells invade internal organs. Signs of FIP include prolonged high fever that does not respond to therapy, lethargy, weight loss, and decreased appetite. Dry FIP, in particular, is difficult to diagnose. While research on various types of treatment continues, there is currently no cure for FIP and no reliable treatment. A vaccine exists, but it is not generally recommended as its efficacy is controversial. The risk of FIP may lessen with good sanitation practices and a reduction of both overcrowding and stress.
Excellent brochures on FeLV, FIV, and FIP are available from the Cornell Feline Health Center, Cornell University, Ithaca, New York 14853-6401. Write to them for details or check out vet.cornell.edu/fhc/. Another excellent source of information is the Winn Feline Foundation, winnfelinehealth.org.
Feline Lower Urinary Tract Disease (FLUTD)
This disease, formerly known as feline urologic syndrome (FUS), is a general term for a set of signs including frequent squatting or straining in the litter box, painful and/or inappropriate urination, or blood in the urine. Causes include cystitis (bladder inflammation), urinary tract infections, crystals in the urine, bladder stones, and less commonly, urinary bladder cancer. Especially in younger cats, there is a good chance that no definitive cause will be found. Lack of water in the diet (exclusive dry food diets), stress and change of seasons are currently among the predisposing factors thought to be involved in leading to FLUTD in cats. Because of their urinary tract anatomy, male cats are more prone to blockages if stones, crystals, or mucous plugs become lodged in the urinary tract. Immediate treatment is necessary to save their lives. FLUTD can sometimes be prevented by diet, and sometimes it can be controlled with diet and drug therapy. Reducing stress through behavioral and environmental enrichment programs is now a part of standard treatment for cystitis. For more information, see indoorcat.org.
Parasites draw their sustenance from a cat’s body. Although parasites rarely kill their hosts, severe parasitic infestations can lead to death. At the very least, parasitic infections can have an adverse effect on a cat’s quality of life. Some parasites are also zoonotic (can affect people). Keeping your cat indoors will help reduce the chance of exposure to parasites. The most common parasites are:
Cats who spend time outdoors or cats who have contact with unprotected pets are most at risk for flea infestation. Flea control is important to prevent flea allergy dermatitis, an irritating and potentially severe skin condition caused by an allergy to flea bites. Fleas also transmit the larval form of one type of tapeworm. There are medications that effectively treat tapeworms, but flea control is necessary to prevent re-infection. Fleas may also transmit Bartonella, the bacteria that cause “Cat Scratch Disease,” as well as a blood parasite called Mycoplasma haemophilus, which can cause severe anemia. In addition, while fleas prefer animals as hosts, they may bite people. Our warm and often humid homes provide perfect shelter (especially carpeting) for flea eggs to hatch and pupae and larvae to hide. A single flea can lay up to 50 eggs daily and 2,000 eggs in a lifetime. Both the cat and the home must be treated to break the lifecycle. Talk with your veterinarian about which flea control method is best for your cats. Only use flea control products labeled for cats. Some flea treatments for dogs can be toxic to cats.
- Ear Mites
These tiny, almost invisible insects live and breed in your cat’s ear canal. They are very contagious, can be passed between cats and dogs, and can be difficult to treat. Headshaking, excessive ear scratching, and crumbly or greasy brown or black matter in the ears suggest an infestation. Your veterinarian can offer treatment options. Do not attempt to treat the ears yourself, and don’t assume that every ear infection is caused by ear mites. Cats also can have bacterial or fungal infections, either alone or in conjunction with the ear mite infection.
These parasites are fairly common, especially in kittens and in stray and other outdoor-roaming cats. Roundworms often are easily detected by a microscopic fecal examination. They are acquired by ingesting the eggs of the parasite, eating an infected host such as a rodent or bird, or through drinking an infected queen’s milk. The white worms live in the small intestines of the cat and grow up to six inches long. The eggs produced by the female worms shed in the cat’s feces and can persist in contaminated soil for years. While treatment is routine (professional deworming is best—some over-the-counter dewormers don’t work), it’s extremely important to treat the cat. Roundworms are a public health concern, potentially causing larval migrans in people. This is a condition most often seen affecting children who dig or play in roundworm-affected sand or soil. The immature roundworms (larvae), when ingested by these children, can migrate to the lungs, liver, or eyes and may cause damage to these organs, including blindness.
Typically detected by the presence of tapeworm segments, these parasites resemble grains of rice or sesame seeds and are found in the area around the cat’s anus. One type of tapeworm is contracted by ingesting fleas and the other by eating animals such as mice and rabbits. Tapeworms attach to the intestine and absorb nutrients. Most cats are asymptomatic, but in some cases cats can develop diarrhea and/or experience weight loss. As described above, treatment involves both medication and flea control.
Coccidia are not worms but rather one-celled organisms that thrive in the intestinal tract and sometimes may cause life-threatening diarrhea. They are detected through microscopic fecal examination. The treatment period is often longer than that for tapeworms and roundworms, and usually involves meticulous scooping of feces from the litter box along with a 14- to 21-day antibiotic regimen.
Common symptoms of hookworms include bloody stool, weight loss, weakness and/or anemia. However, in some cases, particularly in adults, cats may be asymptomatic. Hookworm infection is caused by eating infected animals or ingesting feces that contain infected larvae. Hookworms may be transmitted to humans, causing cutaneous larva migrans. This is a condition where the larval or immature forms of the hookworm travel under the skin in people, creating red, itchy bumps. Deworming treatment is the same as it is for roundworms.
For more information on parasites and pets, visit petsandparasites.org.
This disease can affect cats, but hasn’t been an area of veterinary concentration until recently. In cats, heartworms tend to cause lung disease as opposed to the heart disease that dogs develop. In fact, some cats with symptoms suggestive of feline asthma may actually be suffering from heartworm associated respiratory disease (HARD). Diagnostic testing for heartworms in cats is much more difficult than it is in dogs and often requires a combination of blood tests, x-rays, and ultrasound. There is no cure for heartworms in cats, but some may respond to symptomatic treatment with anti-inflammatory medications and certain antibiotics. Monthly preventive medications, however, are very effective and safe. Since heartworms are transmitted by mosquitoes, cats who roam outside or spend time on porches, decks, or near open windows are at risk for heartworm disease. For more information, visit knowheartworms.org and heartwormsociety.org.
Ringworm is not caused by a worm, as the name may imply. Instead, it is caused by a highly contagious fungus. Although it has a classic “ring” appearance on human skin and is often recognized in cats by hair loss with scaly or red skin, it can mimic other skin and coat conditions as well. Cats also can carry ringworm without showing any signs. Diagnosis and treatment are important because ringworm is contagious to other pets and people. Affected hairs may glow under UV light (Wood’s Lamp), but this occurs in less than half of infected cats, so a fungal culture is often necessary to confirm the diagnosis. Treatment includes both oral and topical medications prescribed by a veterinarian and must continue until fungal cultures are negative. Environmental decontamination is critical to prevent re-infection. The fungal spores are very hardy, and most over-the-counter products are not effective at killing them. Household bleach in a dilution of one part bleach to ten parts water works best. Also, vacuuming well and frequently and washing all bedding are important.
Chronic Kidney Failure (Chronic Renal Failure)
This is a progressive but often manageable disease in which the kidneys lose their ability to perform many important functions, including removal of waste products and conserving water. It can have many causes, but chronic aging changes in older cats are the most common cause. The clinical signs seen most often are excessive drinking and urination. Later signs include weight loss, anorexia, lethargy, vomiting, anemia, and sores in the mouth. Unfortunately, by the time many of these signs are seen, the disease often has progressed significantly. Diagnostic tests include blood work, urinalysis, urine culture (which helps to screen for kidney infection) and, in some cases, x-rays, and ultrasound. Treatment for kidney failure may initially require hospitalization with IV fluids as well as medications to control nausea and vomiting, appetite stimulants, and antibiotics, if needed. Home treatment may start with changing your cat’s diet, but may also involve your administering fluids (a balanced electrolyte solution) by injection under the skin, as well as other supportive medications. Prescription foods may reduce the workload of the kidneys and may slow the progression of the kidney disease, and moist foods in general help to increase water intake. Periodic rechecking of laboratory values and subsequent adjusting of supportive treatments will be recommended by your veterinarian. This is one of many diseases where early detection and intervention may prolong quality of life and lessen suffering, which is another reason semiannual visits to your veterinarian are important.
This occurs when the thyroid, a small gland in the neck that helps to regulate metabolism, becomes enlarged and produces too much thyroid hormone. In most cases, this is due to a benign tumor. The cause of these benign tumors is unknown but is actively being researched. Environmental toxins may play a role. The hallmark sign of hyperthyroidism is weight loss despite a normal or increased appetite. Hyperthyroid cats also may have intermittent vomiting and/or diarrhea as well as increased thirst and urination, skin conditions, behavior changes, etc. Some cats become agitated, hyperactive, and/or more vocal. Hyperthyroidism can be diagnosed through blood work. It is important that kidney and liver function also be assessed as this affects future treatment. Hyperthyroidism can adversely affect multiple body systems, most significantly the heart, so control of the disease is very important. There are three treatment options available:
1. Medication, typically methimazole, needs to be administered daily (usually twice a day) to adequately control thyroid hormone levels. It is generally given in pill form, but can be specially formulated (compounded) into a flavored liquid, chew, or a transdermal gel that can be applied to the inside of the ears. Because this medication is intended only to blunt thyroid hormone production and does not actually cure the condition, methimazole is a lifelong treatment. Occasionally, some cats will experience minor side effects, but the drug has the advantage of being easily adjusted. Cats on oral medication must have exams and laboratory work performed regularly to monitor efficacy and also because treatment affects other organ systems.
2. Radioactive iodine is generally considered the safest and most effective treatment, and it is perhaps the best option for cats with adequate kidney function. In more than 95 percent of cats, it is curative with only one treatment. Also, in the rare case of a malignant thyroid tumor, the thyroid scan that many facilities use prior to treatment will aid in diagnosis and appropriate treatment. Only specialized facilities are licensed to perform the radioactive iodine procedure, and cats must be hospitalized for several days because of the exposure to radioactive materials. A very small number of cats may become hypothyroid after therapy and require thyroid supplementation.
3. Surgery to remove the thyroid glands is usually curative, but hyperthyroidism can recur in some cats if tissue is left behind or if they have thyroid tissue in abnormal locations (ectopic thyroid). Other potential complications include those associated with anesthesia and surgery in general, as well as damage to the adjacent parathyroid gland, which can result in dangerously low calcium levels.
Your veterinarian can assist in choosing the option best suited for your cat’s personality and health, taking economics into consideration as well. Surgery and radioactive iodine are far more expensive initially, but in relatively younger cats, the costs of years of medication and monitoring may exceed the costs associated with the two curative options.
Inflammatory Bowel Disease (IBD)
This disease can cause chronic vomiting, diarrhea, dehydration, and/or weight loss. IBD is characterized by inflammatory cells found in the lining of the stomach and/or intestinal tract. To confirm the diagnosis, an exploratory abdominal surgery or endoscopy with biopsy is needed, but less invasive diagnostics, such as blood tests, x-rays, and ultrasound can help to make a presumptive diagnosis. There is no one specific cause for IBD in cats, and the explanation may vary from cat to cat. Known causes include dietary allergies or intolerances, parasites, bacterial infections, etc. Some cats respond to special diets or supplements. Steroids also may be prescribed, and they often are very effective. Many cats tolerate steroids well enough to use for the remainder of their lives without any serious deleterious effects.
This disease develops when insulin secretion by the pancreas is impaired or when the body’s cells are resistant to the action of insulin, thus inhibiting the body’s ability to regulate blood glucose (blood sugar). The key clinical signs are increased water and food intake, excessive urination, and weight loss. In the later stages, cats may have trouble walking (due to effects on the nervous system) and become extremely lethargic. The disease is diagnosed through blood work and a urinalysis. Diabetic cats may require insulin injections, but some cats can be treated with low carbohydrate diets, especially if diagnosed early (please see Feline Diet and Nutrition for more information). Occasionally, diabetes can be maintained with oral medications, but these are rare exceptions. Not all cats remain insulin dependent forever. Diabetes is far more common in overweight cats, especially middle-age male cats, and its incidence has risen along with the rise in feline obesity.
This disease includes a large group of malignancies that can affect any organ system. Signs and symptoms often are subtle at first, if apparent at all. Examples include masses on or under the skin, diarrhea, vomiting, persistent lameness, decreased appetite, lethargy, weight loss, labored breathing, and difficulty urinating and/or defecating. Unusual bleeding or discharge from any area may be cause for concern. Check your cat on a regular basis for any lumps. Especially with female cats, guardians should periodically check for mammary (breast) masses. If you observe any of these signs or symptoms in your cat, bring them to the attention of your veterinarian.
Many cancers are very aggressive and can accelerate quickly. In some cases early detection is possible. The earlier cancer is diagnosed, the better the chance for effective treatment and a positive outcome. Annual, or ideally semiannual, veterinary examinations will allow your veterinarian to catch weight loss earlier and to detect any abnormal findings at an early stage. Treatment for cancer depends on its type and location. In some cases, surgery, chemotherapy, and/or radiation therapy may lead to remission or a cure.
In others, the goal may be to keep the cat comfortable. Veterinary oncologists are making progress in identifying effective treatments with fewer side effects. Still, our cats can’t live forever, and cancer often is fatal, particularly in elderly cats. The question of whether to treat and how to treat depends on economic realities as well as how to best maintain your cat’s quality of life.
High blood pressure in cats almost always is secondary to another disease process, such as chronic kidney failure or hyperthyroidism. There often are no obvious symptoms, so routine screening is important. Hypertension should never be ignored because it indicates the presence of an underlying condition. Also, if left untreated, hypertension can cause blindness, stroke, or seizures and can hasten the progression of kidney disease, especially in older cats. Treatment of hypertension begins with treating the primary disease. Often, though, antihypertensive medication also is needed, and some of the same drugs that treat hypertension in people are used in cats.
This degenerative joint disease is a painful condition that primarily affects older cats. Unfortunately, much more research is needed to enhance our knowledge about the causes and management of this disease in cats and to approach the level of understanding that we have about arthritis in dogs. The prevalence of arthritis in cats is unknown, but it is thought to affect a significant portion of senior cats (older than 10 years of age) with the elbows showing the highest frequency of obvious disease.
Clinical signs of arthritis in cats are often subtle. Only a small portion of arthritic cats will exhibit lameness or limping. Instead, the signs more commonly seen are behavior changes, such as reduced activity and a decreased ability to perform some of the tasks that they once were able to perform or that they should perform (jumping, playing, etc). Owners may not even initially recognize these signs since many cats are generally less active indoors. Additionally, owners may not interpret the reduced activity as problematic but instead attribute it to advancing age. Arthritic cats also may groom less completely if their mobility or flexibility is reduced, and they may find other normal functions difficult as well, such as getting in and out of the litter box, going up and down stairs, and defecating.
The diagnosis of arthritis can be difficult in cats, and for this reason, the condition is likely under diagnosed. Radiographs are not always helpful; there often is a discrepancy between what is seen radiographically and what is seen clinically. Therefore, owner observations of notable changes in their cat’s behaviors and activity levels are important factors in helping to diagnose arthritis.
Some of the treatment approaches for feline arthritis include: diet restriction if the cat is overweight; home environment changes, including low-sided litter boxes and pet stairs; exercise/rehabilitation/physical therapy; acupuncture/massage; nutraceuticals (glucosamine/chondroitin sulfate); and pain medication.
Some obstetricians still suggest that pregnant women relinquish their cats because of the potential for this protozoal parasite to be transmitted to them, which would potentially cause birth defects, even death, in their unborn children.
"Absolutely, positively, you do not have to give up your cat because you are pregnant; please don’t even consider that," urges Dr. Margie Scherk, a board-certified feline veterinarian from Vancouver, British Columbia, Canada.
Toxoplasmosis (toxoplasma gondii) occurs naturally in the environment. Cats most frequently are infected through eating an infected animal or through eating undercooked meat. Following a meal of infected prey or undercooked meat, an intraintestinal infection cycle begins which is unique to cats. The organism multiplies in the walls of the small intestine and ultimately comes out in the feces. Cats are the only animals to pass the organisms in their infectious stage in their feces. While some cats with toxoplasmosis do become ill, many show no symptoms whatsoever.
Dr. Michael Lappin, professor of small animal internal medicine at the College of Veterinary Medicine at Colorado State University, Fort Collins, explains the specific series of events that must occur for a person to get toxoplasmosis from a feline host. Initially, a person must come in contact with an infected cat, and not all cats are infected. According to Lappin’s research, about 30 percent of cats are positive for toxoplasmosis. Cats pass the organisms in their infectious stage of the disease in their feces for only seven to ten days of their entire lives (when there is an acute infection). To affect an unborn baby, the infection must occur within the first trimester. By scooping the litter box daily, there’s no potential for infection to people because the feces eliminated by a cat carrying toxoplasmosis require from 24 hours to 5 days to become actively infectious. Lappin says he encourages women to wear gloves while changing the box, offering further protection. Scherk prefers delegating the task. "It’s a perfect job for your partner. You’re carrying the baby; at least he can scoop the box."
Signs of an emergency
Seek immediate treatment from your veterinarian or the closest veterinary emergency clinic if your cat:
- Has a seizure (convulsions)
- Becomes ataxic (staggers or has poor coordination, loss of balance) or has vision loss
- Cannot urinate
- Is gasping or has labored breathing
- Has a loss of bladder and/or bowel control
- Becomes comatose or unresponsive
- Paws or scratches excessively at his mouth or face
- Shows evidence of having suffered a serious trauma or accident (bleeding, broken bone, head tilt, etc.)
- Has eaten anything toxic, including certain plants, antifreeze, human medications, etc (a list of dangerous substances can be found at aspca.org)
- Stops eating or drinking completely
- Develops diarrhea that lasts more than 48 hours
- Has atypical vomiting or persistent vomiting of food or fluid
- Passes blood in urine or stool
When in doubt, contact your veterinarian as soon as possible. Your cat can’t tell you what’s wrong, and the problem is not going to correct itself.
Pain recognition and management in cats
There are several reasons why it can be very easy to miss signs that a cat is in pain. First, cats are masters at hiding pain. In the wild, a sick or injured animal is vulnerable to attack, so survival can depend on the animal’s ability to act like everything is fine even when something is terribly wrong. Second, cats don’t exhibit signs of pain the same way people or other animals do. Relatively quiet creatures, cats often won’t whine, cry, or otherwise vocalize when they’re in pain. Just because your cat isn’t crying or acting out doesn’t mean she’s not in pain. Here are some signs that your cat may be in pain:
- Lack of grooming
- Sleeping a lot and/or sleeping in only one position
- Lack of interest in food, water, or surroundings
- Wanting to be left alone
- Growling or hissing when stroked, touched, or moved
- Nonstop purring
- Licking a particular area
- Abnormal body positions, such as a hunched-back or head-in-the-corner stance
- Change in food preferences, sleeping spots, and/or litter box habits
- General irritability or crankiness
- Reluctance to jump to favorite spots, such as window sills and beds
If you notice any of these behaviors (or any other changes in your cat’s regular behavior), contact your veterinarian. Treating pain in cats can significantly speed their healing and recovery from surgery or illness, and can help reduce stress and enhance the quality of life associated with chronic painful conditions such as arthritis. To assist owners and veterinarians alike in recognizing and managing pain in cats, visit: aahanet.org/PublicDocuments/PainManagementGuidelines.pdf.