Does canned food cause diarrhea in cats?

A happy cat after having surgery to remove a piece of foam that was blocking his intestines

A very common thought among cat owners is that canned food causes diarrhea in cats. In fact, last Friday, one of our technicians had a conversation about that exact topic no less than three times!

1) Someone commented on a Facebook post with a question about her neighbor's cats. Her own cats thrive on a canned diet, but her neighbor objects, saying that it gives her cats diarrhea.

2) A woman brought in a kitten for a first visit that was having chronic soft stools and gas. She was concerned that the kitten was getting diarrhea from the canned food, but switching to a dry food did not significantly improve the problem.

3) At a dinner party, a friend leaned across the dinner table and said, "Not to be indelicate, but I'd like to pick your brain about my 3 year old cat's soft, smelly stools." His wife is concerned that canned food was the culprit, but the cat has been having diarrhea since they got her, and cutting out the canned food did not solve the problem. She has had her stool tested and she is up to date on vaccines. They had just moved to a new home and wondered how to approach a new veterinarian about the problem.

Most of the time, diarrhea in cats is not caused by eating canned food. Canned food is very close to what a cat would eat naturally, in the wild - the nutrient balance and moisture content of canned food is close to that of a mouse - and more natural than dry kibbles. It can be easy to blame diet for a cat's smelly, soft stools, but more often, we need to do some detective work to get to the root of the problem.

How do you diagnose the cause of diarrhea?

Usually, when presented with a cat that is having diarrhea, the veterinarian will recommend that the cat be checked for intestinal parasites. That is usually a very treatable reason to have chronic diarrhea. In Michigan, in Oakland County, in 2014, 1 in every 15 cats was positive for roundworms (compared to 1 in 46 dogs). It can also be a very difficult diagnosis to reach. When we test cats for intestinal parasites, the accuracy of the testing has a lot of contributing factors:

- the age of the stool sample. The older the sample, the less accurate the test. Usually a sample should be tested within 24 hours. Some parasites may be absent from the stool unless it is taken directly from the cat to the microscope! Tapeworms are mobile when they are deposited in the litterbox with your cat's stool, so they may wiggle off the stool before it is collected for testing. Tapeworms are more frequently diagnosed by observation of tapeworm segments on the hairs around the cat's anus than by bringing in a stool sample.

- the amount of stool. If a cat is having frequent, terrible diarrhea, it may be difficult to collect a sample, because only small amounts are produced very frequently.

- the life stage of the parasite. Some intestinal parasites do not shed eggs with every stool sample. When we look at a stool sample, we are most commonly looking for the eggs of the parasite, not the worm, itself. Other parasites are single-celled organisms and shed frequently, or their populations may wax and wane. Toxoplasmosis is an infection with a single-celled organism. Cats that are infected with this parasite will start shedding eggs (oocysts) in their stool  between 3-10 days after becoming infected and will only shed these oocysts for a total of 10-14 days. Ever. If you don't test a stool sample within that period, a stool sample will not diagnose this parasite. After that time frame, Toxoplasmosis infection must be diagnosed with blood titers that check for Toxoplasmosis antibodies.

For more information about cats and parasites, visit the Pets and Parasites website.

Sometimes, it may require that we test multiple stool samples before we are able to locate the parasite in the stool. One of our technicians had to check her cat three times before we were able to locate the Giardia that she was pretty sure was infecting her cat.

In cases where we suspect a difficult to diagnose parasite, or a viral or bacterial cause of diarrhea, we may recommend a "diarrhea panel". This test requires a larger stool sample and checks for two species of Campylobacter, Clostridium perfringens alpha toxin (CPA) gene, Cryptosporidium spp., feline coronavirus (FeCoV), feline panleukopenia virus, Giardia spp., Salmonella spp., Toxoplasma gondii, and Tritrichomonas foetus with PCR testing. A PCR test allows for certain types of DNA to be sorted out of a mixture of different types of DNA so that they can be identified. In this way, the laboratory can sort out the normal intestinal bacteria from bacteria that cause disease (are pathogenic), and find traces of parasites that may be present in small quantities, or identify viruses that may be present.

Hairballs can often be a culprit of intestinal maladies in cats. Sometimes, when the hair builds up in the system instead of passing normally, it can be a sign of a bigger issue - skin allergies or external parasites causing the cat to groom excessively, or decreased gut motility (the speed at which food moves through the digestive tract).

Another hairball - too large to pass through the stomach sphincter

Sometimes, a cat may have abnormal anatomy - here, the cat has a gastric diverticulum - a dead-end pouch off the stomach

This cat has a duodenal diverticulum - a dead-end pouch off the upper part of the small intestine

Sometimes, the intestinal problem is related to something the cat ate...anything from rubber bands, shoe strings and hair scrunchies to difficult to digest plant parts, to creepy, grinning toy parts...

Additional testing that might be recommended is highly dependent on the age of the cat, its unique symptoms, and the veterinarian's physical exam. It is highly likely that abdominal x-rays will be recommended. Special contrast studies may be recommended based on the results of the first films - for this, either barium or air will be introduced into the cat's intestinal tract for better imaging. Various blood tests may be recommended - from FeLV/FIV testing, to metabolic testing of kidneys, liver, glucose levels, thyroid levels, or pancreatic function testing.

 

What causes diarrhea in cats?

Sometimes, a cat may have a sensitive stomach that causes them to have diarrhea when their food is switched too rapidly. If they have eaten only dry food all their lives and are suddenly offered only canned food, in this case, canned food may cause diarrhea. However, if you transition food gradually, this should prevent diarrhea related to food transition. Cats may have a sensitivity to a certain protein in their diet. Very commonly, we hear of cats with beef sensitivities, though more in the context of vomiting versus diarrhea. (It make some sense, since we're pretty sure that domestic cats do not naturally hunt down cattle for dinner. Lions, yes. Fluffy, no.) It may be that a cat will have an intolerance to a particular brand of canned food, too, but rarely does canned food as a whole food group cause diarrhea. This would be similar to a human being unable to eat any type of soup or stew without digestive issues.


Besides intestinal parasites and food transitions, other problems that can cause diarrhea in cats include:
- viruses such as Distemper, Feline Leukemia, FIV, and Coronavirus/FIP
- toxin ingestion - plant or others
- Salmonella
- fungal infections
- body-system diseases including: kidney disease, hyperthyroid disease, pancreatitis, and diabetes
- cancer
- inflammatory diseases such as inflammatory bowel disease (IBD), fiber-responsive diarrhea, colitis
- pancreatic insufficiency
- foreign body ingestion (your cat ate a toy!) or other bowel obstruction (hairball, constipation)
- spoiled food
- certain medications (for example, some antibiotics are commonly known to cause diarrhea)

It may be yucky to look at, but using this chart to score your cat's stool can be very helpful!

What can I do to help the veterinarian diagnose my cat?

When trying to hunt down the cause of a complex diarrhea case, it may be helpful to keep a diary of what food you fed your cat each day and rate their stool consistency. We tend to sort cats' stools into the following categories:

- solid, normal stools - "Tootsie Rolls"
- soft stools with some form, but may appear to be "melting", also known as "soft serve stools"
- soft stools with little to no form - "pudding stools"
- liquid diarrhea, may be confused with urine in clumping litter, may be volatile, often the cat may be  unable to make it to the litterbox. This liquid may be brown in coloration or may be clear and difficult to distinguish from vomit.

Note any blood or mucus in the stool. Fresh red blood (frank blood) may be related to irritation of the intestinal tract or anus. Dark, tarry stools or blood that looks like coffee grounds contains older, clotted blood and is a more critical and severe concern than fresh blood. Mucous in the stool is often thick and clear and can be passed with the stool or separately. You may want to snap photos of the diarrhea to show your veterinarian. It can often be helpful, and we will never be offended. Note the frequency of the diarrhea and any other symptoms your cat may have.

When should you see the veterinarian?

Diarrhea is often considered to be a smelly nuisance, however, significant, chronic diarrhea can cause dehydration and malnutrition and can become a life threatening situation.

Contact your veterinarian right away if your cat’s diarrhea:

• is accompanied by repeated vomiting, lethargy, loss of appetite, abdominal pain, generalized weakness, or fever. Vomiting of a dark green liquid (bile) is commonly an indication of a complete intestinal blockage.
• contains large amounts of frank blood.
• is black or tarry in color.
• might be related to ingesting something toxic.
• occurs in a kitten under nine months of age, particularly if vaccines were missed.
• occurs in an elderly or medically frail animal.
• fails to respond or gets worse despite 48 hours of symptomatic home care.

Your cat wants to stop having diarrhea as much as you want him to!

 If you are new to an area and are not sure how to approach a new veterinarian with your problem, it may be best to simply collect a fresh stool sample and take it into the office. A stool sample can often be analyzed without first seeing a cat, though if medication needs to be dispensed, an exam will be necessary. This is because pharmacy laws in most states require an established doctor-patient relationship before any medication can legally be dispensed. If the parasite exam is negative, you will also need to bring your cat in for an exam and consultation about your cat's lifestyle and unique characteristics, so it may be best to contact the new veterinarian and schedule an appointment and bring a stool sample with you at the same time. Having your records sent from your old veterinary hospital to your new hospital will also be helpful, because it will give your new veterinarian an idea of your cat's past weight gains and losses, vaccine history, and any bloodwork or x-rays that have been done in the past.

Additional resources:
Pet Education: Diarrhea in cats: Causes, Diagnosis and Treatment
Cat Diarrhea Causes, Symptoms, Treatment and more

Client question: How often should my cat have his teeth cleaned?

Question:  I clicked on your dental care link and thought it was very educational. At what age should a cat have it's teeth cleaned? And how often? Thanks.

Exclusively Cats Veterinary Hospital Thanks for a great question! 

Fractured canine tooth with exposure of the nerve and blood supply

 
A cat's dental health is dependent on many things: age, overall health, FeLV/FIV status and breed or hereditary characteristics. Many cats may need a dental cleaning as early as 4 years of age, if we are talking about preventing dental disease. Breeds such as Persians, who have short noses, still have the same number of teeth in their mouths as longer-nosed cats, and develop dental disease more rapidly due to tooth-crowding. Cats that are FeLV or FIV positive or have other diseases that decrease the effectiveness of their immune system may need dental cleanings more frequently because they are more susceptible to the bacteria that build up in the mouth. Cats that are adventurous explorers and fall and break a tooth, or those that chew on hard objects frequently may need more frequent care or emergency care. 

This Abyssinian kitten has all her adult teeth except her upper canines. X-rays show that she has no adult canines! When and if she loses her baby teeth, she will be missing two teeth.

Generally, we recommend that cats come in for a fluoride treatment around the age of 7 months, when all the adult teeth should have erupted. At this time, fluoride can be applied to the teeth (some cats will already have a little tartar buildup, which we will clean!) to strengthen the enamel - this application is most effective at strengthening before 18 months of age. After that, fluoride applications help prevent pain due to exposed dentin in inflamed mouths. We can also check to see if there are any abnormalities - extra teeth, missing teeth, retained baby teeth, teeth out of position, etc. that will cause problems later in life and require more care than the average cat.

This kitten has an upper tooth that is causing injury to his lower gum

We like to examine cats' mouths annually and their wellness exams to decide whether the cat will need a dental cleaning in the near future. Most cats will benefit from annual cleanings, but some cats may need cleanings every 6 months, and others may be able to go 2-3 years between cleanings. We try to balance the aggressiveness of our recommendations for treatment with the cost of treatment - since they require anesthesia for cleanings, we know that it may be daunting to consider the cost of a dental procedure. However, just like human dentists, veterinarians who advocate good oral health care for cats would prefer to perform a "dental prophylaxis" or cleaning, versus performing "dental surgery" and tooth extractions! We are sure that our patients would prefer it, too!

Flooding the Litterbox: Chronic Kidney Disease and your cat

CHRONIC KIDNEY DISEASE: An Overview

Before we re-write the book on Chronic Kidney Disease, please note that there are two extremely thorough and excellent resources for people with cats that have Chronic Kidney Disease (CKD) that we would like to recognize: 

Feline CRF (Chronic Renal Failure) Information Center
Tanya's Comprehensive Guide to Feline Chronic Kidney Disease

What is meant by the terms “Chronic Kidney Disease” and "Chronic Kidney Failure"?

The term "chronic kidney failure" suggests that the kidneys have stopped working and are, therefore, not making urine.  However, by definition, kidney disease is the inability of the kidneys to remove waste products from the blood.  This definition can occasionally create confusion because some will equate "kidney failure" with "failure to make urine".  Kidney disease is NOT the inability to make urine.  Ironically, most cats in kidney failure are actually producing large quantities of urine, but the body’s wastes are not being effectively eliminated. This is why many people avoid the term "kidney failure" and prefer "kidney disease". Because the kidneys are so efficient at their job and because cats are so adept at hiding their illnesses, it has been determined that a cat can lose up to 75% of normal kidney function before they begin to act sick. This is one reason that annual checkups with your veterinarian are so important!

There does come a point in CKD at which a cat's kidneys have been destroyed to the point where urine is no longer produced (anuria), but hopefully, the problem is recognized, discussed and treated before this is the case.

When is this likely to happen in my cat?

Commonly, chronic kidney disease is considered to be the result of aging - a “wearing out” process.  Most of the time, when chronic kidney disease is diagnosed, the cause is unknown. Biopsy of the chronic kidney usually results in a non-specific assessment called "chronic interstitial nephritis" - a hardening and inflammation of the filtration structures in the kidney. 

There are some known contributing factors to kidney disease:

• Polycystic Kidney Disease:  an inherited disease seen in certain purebreds where one or more fluid-filled cysts start to gradually replace normal kidney tissue 
• Kidney tumors: lymphoma is a common type of cancer seen in cats, and it can affect many different organs, including the kidneys. White Blood Cells called lymphocytes become affected and interfere with normal kidney structure
• Infections: bacterial infection of the kidneys (known as 'pyelonephritis') may cause enough damage to the kidneys to cause CKD. Kidney infections are usually a complication of a long-standing, untreated urinary tract infection, but can occur more quickly in older cats with dilute urine, cats on immunosuppressive drugs, or cats with concurrent diseases such as diabetes or FIV.
• Toxins: certain toxins and drugs can damage the kidneys - for example, cats that eat plants from the lily family, drink antifreeze or ingest pills from the pain-reliever family like acetominophen or ibuprofen
• Glomerulonephritis: there are small filtration units in the kidneys called "glomeruli" that filter toxins from the bloodstream. These filters can become inflamed for a variety of reasons and if the inflammation is prolonged, this can lead to CKD

For most cats, the early signs occur at about 10-14 years of age. However, some cats may experience early onset kidney disease at 5-7 years or younger. About 20-50% of cats will be diagnosed with CKD at some time in their lives.

What changes are likely to occur in my cat?

The kidneys are the body's filters, removing toxins from the blood and excreting them in the urine. When aging causes the filtration process to become inefficient and ineffective, blood flow to the kidneys is increased in an attempt to increase filtration.  This results in the production of more urine.  To keep the cat from becoming dehydrated, due to increased fluid loss in the urine, thirst is increased so the cat drinks more water.  

Other job functions of the kidneys:

• Maintaining hydration - the body's water balance
• Maintaining balance of salts and electrolytes
• Maintaining the acid balance of the body
• Maintaining normal blood pressure
• Producing hormones involved in calcium processing, red blood cell production, blood clotting and immune system health

Early signs of CKD:

• increased water consumption (polydipsia)
• increased urine production (polyuria) with or without litterbox avoidance
• mild or gradual weight loss 

Signs of more advanced kidney disease include:

• loss of appetite/severe or rapid weight loss
• depression or lethargy
• vomiting
• diarrhea
• poor coat
• anemia
• very bad breath (uremia)
• occasionally, ulcers will be found in the mouth

Additionally, cats with kidney disease tend to have associated high blood pressure.

How is chronic kidney disease diagnosed?

The diagnosis of kidney disease is made by determining the level of two waste products in the blood:  blood urea nitrogen (BUN) and blood creatinine.  A urinalysis is also needed to complete the study of kidney function, with special attention paid to the "specific gravity" of the urine. Urine specific gravity is a measure of the "stuff" (such as proteins) in the urine that make it different than water. Since cats are descended from desert animals, they are very good at concentrating their urine - eliminating a lot of "stuff" and conserving a lot of water. Average specific gravity of cat urine is greater than 1.035, and may be as high as 1.060 if they eat a dry-food only diet. If the urine specific gravity drops below 1.035, it can be a red flag that indicates the cat is not concentrating urine well for some reason - for example: drinking more water than usual or losing kidney function. Comparing the BUN and creatinine levels in the blood to the urine specific gravity can be very informative to the veterinarian.

Although BUN and creatinine levels reflect kidney failure, they do not predict it.  A cat with marginal kidney function may have normal blood tests.  If that cat is stressed with major illness or surgery, the kidneys may fail, sending the blood test levels quickly into the abnormal range. Additionally, other factors can affect the body's BUN and creatinine levels, such as kidney infection, hyperthyroid disease, muscle loss, and anorexia (lack of food intake).

Since this is basically just a wearing out process, can it be treated with anything other than a kidney transplant?

Yes, it can. We must recognize that your cat’s kidneys have reached this point due to aging, so they will never be normal again, but many cats still have enough functional kidney tissue so treatment can be very rewarding.

Treatment generally has two phases.  If your cat has reach a crisis, the first phase is to “restart” the kidneys.  The cat is hospitalized and large quantities of intravenous fluids are given to “flush out” the kidneys.  This flushing process, called diuresis, helps to stimulate the kidney cells to function again.  If enough functional kidney cells remain, they may be able to adequately meet the body’s needs for waste removal.  Fluid therapy includes replacement of various electrolytes, especially potassium.  Other important aspects of initial treatment include proper nutrition and drugs to control vomiting and diarrhea.

There are some exciting new developments in diagnosis and treatment of feline chronic kidney disease that will hopefully be very beneficial when they become available outside of university research settings.

A newly discovered biomarker of kidney disease may provide earlier detection and allow for closer monitoring and better, earlier treatments.

Stem cell therapy has been showing some promise in treating feline kidney disease, too. The stem cells for this therapy are cultivated from the fat of young, healthy cats; donor animals are not harmed.

What can I expect from this phase of treatment?

There are three possible outcomes from the first phase of treatment:

1) The kidneys will resume functioning and continue to function for a few weeks to a few years. 
2) The kidneys will resume functioning during treatment but fail again as soon as treatment stops. 
3) Kidney function will not return. 

Unfortunately, there are no reliable tests that will predict the outcome. The best your veterinarian can
do is assess the response of the cat's blood values and attitude while hospitalized and draw on their experience as to whether they recommend continued treatment, and if so, how aggressive that treatment needs to be to keep your cat healthy. A close relationship with your veterinarian will help them design a continuing treatment plan to keep your cat feeling healthy for as long as possible. That plan will need to be continually adjusted based on your cat's progress.

 If the first phase of treatment is successful, what happens next?

The second phase of treatment is to keep the kidneys functioning as long as possible. This is accomplished with one or more of the following, depending on the situation:

1. A high quality diet.  This helps to keep the blood tests as close to normal as possible, which usually makes your cat feel better.  We can recommend a commercially prepared food that has the quantity and quality of protein needed by your cat.

2. Potassium supplementation.  Potassium is lost in the urine when urine production becomes excessive.  A potassium supplement will replace that loss.  Low potassium levels have been shown to further reduce kidney function.  This is the second reason that a potassium supplement is recommended.  Monitoring of your cat’s potassium will guide our decision to supplement.

3. A phosphate binder.  One of the secondary things that occurs in kidney failure is an elevation of the blood’s level of phosphorus.  This also contributes to lethargy and poor appetite.  Certain drugs will bind excess phosphates in the intestinal tract so they are not absorbed, resulting in lower blood levels of phosphorus.  Phosphate binders are helpful only when feeding a phosphate restricted diet, as there is far too much phosphate in a  “normal diet” for these binders to be of benefit.

4. Fluids given at home.  Once your cat is stabilized, fluids can be given under the skin (subcutaneously). This serves to continually “restart” the kidneys as their function begins to fail again.  This is done once daily to once weekly, depending on the degree of kidney disease.  Although this might not sound like something you can do, you will be surprised at how easily the technique can be learned and how well most cats will tolerate it.

5. A drug to regulate the parathyroid gland and calcium levels.  Calcium and phosphorus must remain at about a 2:1 ratio in the blood.  The increase in blood phosphorus level, as mentioned above, stimulates the parathyroid gland to increase the blood calcium level by removing it from bones.  This can be helpful for the sake of the normalizing calcium:phosphorus ratio, but it can make the bones brittle and easily broken.  Calcitriol  can be used to reduce the function of the parathyroid gland and to increase calcium absorption from the intestinal tract.

6. A drug to stimulate the bone marrow to produce new red blood cells.  The kidneys produce erythropoietin, a hormone that stimulates the bone marrow to make red blood cells.  Therefore, many cats in kidney failure have a low red blood cell count, anemia.  Epogen, a synthetic form of erythropoietin, will correct the anemia in most cats.  Unfortunately for some cats, the drug cannot be used long term because the immune system recognizes the drug as "foreign" and will make antibodies (immune proteins) against it.

How long can I expect my cat to live?

The prognosis is quite variable depending on response to the initial stage of treatment and your ability to perform the follow-up care.   However, we encourage treatment in most situations because many cats will respond and have good quality life for up to 4 years. 

Chronic Nasal Discharge in Cats

CHRONIC NASAL DISCHARGE

What is meant by the term "Chronic Nasal Discharge"?

When a cat has a discharge from its nose that lasts more than 2 months, it is considered chronic.  The discharge may be thin and clear like water (serous), thick and yellow or green like pus (purulent), bloody (sanguinous or hemorrhagic), or a combination. Clear fluid or mucousy discharge may be an indication of irritation or viral infection. Thick, yellow fluid or pus may be a sign of a bacterial infection. Reddish fluid can be a sign of intense or chronic irritation, destruction of the nasal mucous membranes or bones (turbinates). Trauma can also cause a bloody nasal discharge.

Foreign bodies only affect one nostril. Fungal infections and tumors may affect one or both nostrils, while viral infections most often affect both, though one side may be worse than the other.

What causes a chronic nasal discharge?

A view into the nasal canal and the papery turbinate bones

Chronic nasal discharge is not a diagnosis; rather, it is a term that describes the signs of disease in the nose and frontal sinuses.  Almost all disease conditions that occur in the nose will cause irritation and inflammation to the lacy bones in the nose, called turbinates.  The presence of disease in the nose is called rhinitis.  The turbinate bones are easily distorted and destroyed.  When that happens, bacteria that normally live in the nose grow rapidly, causing a secondary bacterial infection.

The frontal sinuses are hollow cavities in the skull and are located just above the eyes.  They are connected to the nasal cavity by a small canal.  Most diseases that occur in the nasal cavity have the ability to move through these canals into the frontal sinuses.  When the sinuses become involved and develop inflammation, this is called sinusitis.

Chronic nasal discharge may result from several disorders involving the sinuses and nasal cavity.  These include:

                Chronic viral infection

                Chronic bacterial infection

                Chronic fungal infection

                Dental disease

                Nasal foreign body (e.g. grass seed)

                Nasal tumor

                Inflammatory polyp

                Parasite infection

What tests should be done to make an accurate diagnosis?

There are several diagnostic tests that should be done for a cat with a chronic nasal discharge.  A blood profile will often detect underlying diseases that can contribute to a nasal disease.  Testing for the feline leukemia virus (FeLV) and the feline immunodeficiency virus (FIV) is important because these viruses have the ability to suppress the cat's immune system, making recovery from normally mild infections difficult (or even impossible). 

Nasal x-ray. One side of the nose has poor detail which suggests that the delicate bones of the nasal passages, the turbinate bones, are being destroyed.

It is very important to make radiographs (x-rays) of the skull.  Special positions are necessary to view the nasal cavity and frontal sinuses.  These require sedation or a short-acting anesthetic.  A nasal flush is a diagnostic procedure used to collect material from deep within the nasal cavity.  This material can be studied under the microscope (cytology) and can also be cultured.  Although it is not particularly traumatic to the cat, anesthesia is required, so this procedure is usually done in conjunction with radiographs.  This allows more than one procedure to be done while the cat is under anesthesia.

Anesthesia allows close inspection of the throat, the area above the soft palate, and the nasal canals. This cat had a large buildup of extremely thick mucus above the soft palate.

Some veterinarians have a specialized instrument called an endoscope which allows the veterinarian to actually look inside the nose, as well as to examine the back of the throat and the area around the soft palate.  In order to pass this small flexible tube into the area of interest, anesthesia is required.

There are some diseases that can only be diagnosed with a biopsy of material deep within the nasal cavity.  A biopsy requires recovery of an actual piece of tissue, so surgery is often required for this procedure.

Fungal organisms and a plaque of fungal growth inside the nose of a cat 

Foreign objects within the nasal passage can sometimes be detected with radiographs.  If a foreign body is suspected but not visualized, endoscopy may be helpful, depending on where the foreign body is located.  For some cases, exploratory surgery of the nasal cavity is needed.

As you can see, it may require several days or weeks of testing to determine the cause of a chronic nasal discharge.  When the diagnosis remains elusive, more sophisticated tests may be required.  Veterinarians unable to perform these tests often refer the cat to a specialist.

How is a chronic viral infection treated?

Respiratory viruses, which can infect the nose, may persist and lead to long term viral rhinitis/sinusitis.  No drugs are available to kill these viruses so this type of infection is often incurable but many cats respond to antiviral medications such as Famciclovir.

How is a chronic bacterial infection treated?

Administration of antibiotics alone is usually unsuccessful in curing bacterial infections of the nose and sinuses because the bacteria have become entrapped within the turbinates, and reinfections are frequent.  Although many cats improve while taking antibiotics, cortisone, or antihistamines, they may relapse when these drugs are discontinued.  The use of drugs that stimulate the immune system and the surgical removal of the turbinates have been successful in some cats.  However, others do not respond well.  Overall, the prognosis is guarded.

How is a chronic fungal infection treated?

The most common fungal infection in the nose is caused by Cryptococcus neoformans. Because some of the drugs used to treat this organism are quite expensive and will occasionally cause adverse effects, they are not used unless a firm diagnosis is made.  Fortunately, the newer antifungal drugs have fewer significant side effects and many cats with fungal diseases can be successfully treated.  If the cat is infected with the feline leukemia virus or feline immunodeficiency virus, the outcome will usually be less favorable.

The image below shows a cat named Parker who came to us with a severe swelling in her nose. Microscopic evaluation of samples collected from her nose showed the fungal organism Cryptococcus. Treatment was started and over time, her nose returned to normal.

How is dental disease treated? 

A cat's tooth roots are located very close to the sinus cavity, and if the tooth becomes infected, pus or fluid may drain from the nose. If the infected tooth becomes a severe enough problem, the cat may have facial swelling or swelling of the eye, the tongue may stick out, or the tooth may completely fall out, leaving an opening straight into the sinus cavity.

Disease of this type is treated with a thorough dental cleaning and extraction of the infected teeth, followed by a course of antibiotics. If the disease is bad enough, the cat may be prescribed antibiotics prior to dental care, too.

Read more about what is involved in feline dental care.

How is a nasal foreign body treated?

Nasal mites

When a piece of grass, a seed, parasites or other foreign material lodges in the nasal cavity, the membrane which lines the nose produces large amounts of mucus in response to the irritation.  In addition, affected cats will sneeze violently in an attempt to expel the foreign body. 

If the foreign body cannot be sneezed out, the veterinarian must take steps to remove it.  When a nasal foreign body is suspected but cannot be seen on radiographs or with an endoscope, exploratory surgery may be needed.  If it is found and removed, the prognosis is good.

The following video shows the removal of a Cuterebra larva that was lodged in a cat's nose. He had chronic nasal discharge and excessive sneezing that was not improved with antibiotic treatment. After the Cuterebra was removed, his nasal discharge went away and he stopped sneezing.

How is a tumor treated?

Most nasal tumors are malignant.  Complete surgical removal is very unlikely, so chemotherapy or radiation therapy must be considered.  Unfortunately, many nasal tumors do not respond to either treatment, so the prognosis is poor.  However, when surgery is performed to get tissue for biopsy, most surgeons remove as much of the tumor as possible.  Following this procedure, the cat may be greatly relieved of the nasal discharge and remain improved for several months.  However, in almost all cases, the tumor can be expected to recur. In some cases, however, chemotherapy and/or radiation treatment are successful and the cat will go into remission for as long as several years. It is notable that after a cat has been treated with radiation, the hair at the site of the treatment will likely change color.

This 12 year old cat has been having chronic nasal discharge and sneezing for 2 weeks. He has significant dental disease, but another likelihood at his age is that he may have a tumor. Dr. Brooks' plan for him is to extract his infected teeth and perform a surgical biopsy to determine the extent of his problem.

Several of this cat's teeth have already fallen out and another is almost ready to.

How is an inflammatory polyp treated?

Inflammatory polyps are non-cancerous masses of tissue that are composed of inflammatory cells. Surgery is often successful in removing much of the polyp, but there is a high probability of regrowth if all of the polyp cannot be removed.  Since polyps often begin in the internal ear and grow down the Eustachian tube into the back of the nose, their removal can require extensive surgery that may not be completely successful.  The prognosis for an inflammatory polyp is guarded because the entire polyp cannot be removed in some cases, however, if the entire polyp is successfully removed, the cat will completely recover.

The cat below had an extremely large nasopharyngeal polyp. Once it was removed, her sneezing and nasal discharge resolved completely!

Any time that your cat has discharge from the nose, it is a good idea to have the cat examined by a veterinarian, because the potential causes of chronic nasal discharge are extremely varied, and treatment for chronic nasal discharge is highly dependent on the cause.