Bacterial Cystitis in Cats

While quiet common in Dogs, bacterial infection of the bladder, or bacterial cystitis, is not seen as frequently in cats. Unfortunately, that means it’s often overlooked in cats altogether and/or mistreated.

What are the symptoms of bacterial cystitis in cats?
Symptoms associated with a bacterial cystitis can include:

  • Hematuria (blood in the urine that may or may not be seen in a litter pan)
  • Stranguria (straining and/or discomfort on urination)
  • Pollakiuria (increased frequency of urination/trips outside or to the litter pan with typically smaller volumes)
  • Incontinence/accidents (urinating in inappropriate places)
  • Discomfort (evidenced by restlessness, abdominal pain, crying or excess grooming)

Some of these signs will be easy to recognize in an indoor cat that uses a litter pan, but more challenging in a cat that goes outside since we don’t tend to walk our cats outdoors and aren’t typically standing on top of them when they urinate. [Editor’s Note: This is one of many reasons why keeping your cat indoors is a safer than letting him out. Read more>]

Sometimes, there will be no symptoms whatsoever. In this case, you may only realize the infection exists if your veterinarian is doing routine screening tests or running tests for some other unrelated complaint.

Is my cat at risk of bacterial cystitis?
Bacterial cystitis occurs when bacteria find their way into the otherwise sterile environment of the bladder/urinary tract. There are certain circumstances that can increase your cat’s risk of developing a bladder infection including:

  • The presence of bladder stones, crystals, polyps or tumors that can cause irritation and harbor bacteria
  • An underlying medical condition, such as, feline leukemia virus, feline immunodeficiency virus, diabetes mellitus, hyperthyroidism, and chronic kidney disease

Can anything else cause cystitis?
Yes, other things can. The term cystitis only refers to any inflammation in the bladder. In bacterial cystitis that inflammation is due to a bacterial infection. However, bacterial cystitis accounts for only a small fraction of all feline cystitis cases—only 1-3% according to Alleice Summers, DVM. In her book, Common Diseases of Companion Animals, Alleice also outlines a study run at Ohio State. During this study 132 cats were examined specifically for symptoms of cystitis and 61% of them were found to have something called idiopathic cystitis –not a bacterial infection.

How do you confirm and treat bacterial cystitis?
A urine culture will help your veterinarian determine if your cat has an infection or not.

If bacteria are identified in your pet’s urine sample then an antibiotic sensitivity screening should be performed to determine the best antibiotic to use to treat your pet’s infection. Taking these steps in order to choose the correct antibiotic from the start can ultimately save you time and money; it can also save your pet from unnecessary discomfort associated with further delay in clearing the infection.

The timing and number of any follow-up visits and repeat cultures will depend on your pet’s individual situation. Your veterinarian may recommend repeating cultures during antibiotic therapy, even after your pet has finished the course of treatment, to be absolutely sure that the infection was resolved and that it did not recur.

One final note—If your cat is older and has bacterial cystitis in addition to kidney disease, be sure to ask your veterinarian if there is indication for long term (possibly lifelong) antibiotic treatment. Many of these cats never truly clear their infections. In which case, staying on antibiotics is better for the cat than intermittent treatment.

If you have any questions or concerns, you should always visit or call your veterinarian -- they are your best resource to ensure the health and well-being of your pets.

Feline idiopathic cystitis

Feline idiopathic cystitis (FIC) or feline interstitial cystitis or cystitis in cats, is one of the most frequently observed forms of feline lower urinary tract disease (FLUTD). Feline cystitis means "inflammation of the bladder in cats". The term idiopathic means unknown cause however, certain behaviours have been known to aggravate the illness once it has been initiated. It can affect both males and females of any breed of cat. It is more commonly found in female cats however, when males do exhibit cystitis, it is usually more dangerous. [1]

Despite the shared terminology, cases of feline idiopathic cystitis, as opposed to human cystitis episodes, are sterile. In other words, they do not involve a primary bacterial infection. If upon investigation the inflammation of the feline bladder is in fact found to be the result of an infection, then it is described as a feline urinary tract infection (UTI) or less commonly, feline bacterial cystitis. However, UTIs in cats under the age of 10 years old are very rarely encountered. [2] [3] In cats over 10 years of age, UTIs are much more common and idiopathic cases are much less frequently observed. [4] On the other hand, FIC does show several similarities to an analogous disease in humans called bladder pain syndrome. [5] [6]


Treatment given for a UTI depends on its cause, but is likely to include:

  • Pain relief.Anti-inflammatory pain relief (NSAID) is excellent at soothing bladder pain and inflammation.
  • Bladder supplements. Bladder supplements are designed to soothe the lining of the bladder, although, there is no solid evidence to prove that they work.
  • Antibiotics. A short course of antibiotics is usually an effective cure for a UTI. It’s very important to follow your vet’s instructions and complete the full course. If you stop your cat’s antibiotics early, it could mean some of the remaining strongest remaining bacteria survive and a more severe infection will develop.

Watch our video on how to give your cat a tablet:

What is FLUTD?

Feline lower urinary tract disease, or FLUTD, is a term used to describe a group of disorders or diseases that affects a cat’s lower urinary tract (bladder or urethra). FLUTD is diagnosed after causes like urinary tract infection (UTI) or kidney stones have been ruled out. Causes include crystals or stones in the bladder, bladder infections, urethral obstruction, inflammation in the urinary bladder (sometimes referred to as interstitial or idiopathic cystitis), and other abnormalities in the urinary tract. FLUTD is one of the most common reasons cats are taken to the vet.

Yarmouth Veterinary Center

• "Bacterial" refers to bacteria "cystitis" is inflammation of the bladder "bacterial cystitis" is inflammation of the bladder caused by bacterial infection

• Result of bacterial colonization of the urinary bladder and/or upper portion of the urethra (the tube from the bladder to the outside, through which urine flows out of the body) the lower urinary tract includes the urinary bladder and the urethra

Signalment/Description of Pet

• More common in dogs than in cats

• All ages affected, but occurrence increases with age because of a greater frequency of other urinary tract problems (such as urinary stones [known as "uroliths"], prostate disease, and tumors) that increase the likelihood of secondary bacterial infection of the urinary tract

• Uncommon in cats 6 years old or younger common in cats 10 years old or older

• More common in female than in male dogs

• Occurrence in male and female cats is similar

Signs/Observed Changes in the Pet

• Frequent voiding of small volumes of urine (known as "pollakiuria")

• Difficulty or painful urination (known as "dysuria")

• Urgency to urinate (or an apparent loss of ability to control urination during periods of confinement)

• Urinating in places that are not customary (such as in the house)

• Bloody urine (known as "hematuria") and cloudy or malodorous urine in some pets

• Sudden (acute) infection-bladder or urethra may seem tender on palpation during physical examination

• Feeling the bladder through the abdomen (known as "palpation") on physical examination may stimulate urination

• Long-term (chronic) infection-wall of the bladder or urethra may be thickened or abnormally firm

• Secondary infection-signs related to the underlying problem

• Most common bacteria that cause lower urinary tract infection-Escherichia, Staphylococcus, and Proteus (more than half of all cases)

• Common bacteria that cause lower urinary tract infection-Streptococcus, Klebsiella, Enterobacter, Pseudomonas, and Corynebacterium

• Conditions that cause the urine to remain in the bladder for prolonged time periods (known as "urine stasis") or incomplete emptying of the bladder

• Conditions that disrupt normal lower urinary tract lining defenses (those properties that protect the lower urinary tract from bacterial colonization)

• Conditions that reduce or bypass anatomic and functional barriers to bacteria moving up the urinary tract (such as loss of muscle tone or length of the urethra)

• Conditions that compromise the antibacterial properties of urine itself (such as changes in urine pH or concentration and low levels of urea and certain organic acids)

• Treat as outpatient, unless another urinary abnormality (such as urinary tract blockage or obstruction) requires inpatient treatment

• Regulating urination to coordinate with antibacterial drug treatments may improve therapeutic efficacy

• Restrictions not necessary, but may be indicated for other urinary tract diseases (such as kidney failure or urinary tract stones [urolithiasis])

• Except when a another urinary tract disorder requires surgical intervention, management of bacterial cystitis does not involve surgery

Medications presented in this section are intended to provide general information about possible treatment. The treatment for a particular condition may evolve as medical advances are made therefore, the medications should not be considered as all inclusive

• Antibiotics-suggested antibiotics include penicillin (such as ampicillin) for Staphylococcus, Streptococcus, or Proteus trimethoprim-sulfadiazine for Escherichia coli cephalexin for Klebsiella tetracycline for Pseudomonas

• Bacterial culture and sensitivity testing provides identification of bacteria present in urine and information about antibiotics to which the bacteria is susceptible if the infection does not respond as expected to the first antibiotic prescribed, base choice of antibiotics on results of sensitivity test

• Antibacterial drugs usually are most effective when given every 8 hours however, fluoroquinolones and trimethoprim-sulfa products are effective when given every 12 hours-give antibiotics and any other medications as directed by your pet's veterinarian

• For sudden (acute), uncomplicated bacterial infection of the bladder (bacterial cystitis)-treat with antimicrobial drugs for 7-10 days long-term (chronic) bacterial cystitis may need treatment for up to 4-6 weeks duration of treatment for complicated bacterial cystitis depends on the underlying problem

• Low-dose, bedtime antibacterial therapy can be used to prevent infections in pets that have frequent recurrence of bacterial cystitis the drug should be given after the pet has urinated for the last time each evening

• Other possible antibiotics include enrofloxacin and nitrofurantoin, as well as ceftiofur, gentamicin, or amikacin, which must be given by injection

• When the beneficial effects of the antibiotic treatment is in doubt, culture the urine 2-3 days after starting treatment-if the drug is effective, the bacterial culture will be negative

• Continue treating at least 1 week after resolution of blood in the urine (hematuria) white blood cells or pus in the urine (known as "pyuria") and protein in the urine (known as "proteinuria")-failure of urinalysis findings to return to normal while an episode of urinary tract infection is being treated with an effective antibiotic (that is, as indicated by negative urine culture) generally indicates some other urinary tract abnormality (such as urinary stones [uroliths], tumor)

• Rapid recurrence of signs when treatment is stopped generally indicates either another urinary tract abnormality or that the infection extends into some deep-seated site (such as the prostate or kidney)

• Successful cure of an episode of urinary tract infection is best demonstrated by performing a bacterial culture of the urine 7-10 days after completing antibiotics

• Pets being given low-dose bedtime antibiotics for frequent reinfection should have a bacterial culture of the urine performed every 1-2 months

Preventions and Avoidance

• Avoid indiscriminate use of urinary catheters

• Pets with frequent reinfection can be given bedtime therapy to prevent reinfection

• Associated health risks include development of urinary tract stones (urolithiasis) and extension of infection to other portions of the urinary tract (such as the kidneys) or beyond to the blood (known as "septicemia"), to the spine (known as "diskospondylitis"), and to the heart (known as "bacterial endocarditis")

• Failure to detect or treat effectively may lead to bacterial infection/inflammation of the kidney (known as "pyelonephritis") or formation of a particular type of urinary tract stone (known as "struvite uroliths")

Expected Course and Prognosis

• If not treated, expect infection to persist indefinitely

• Prognosis for pets with uncomplicated bacterial infection of the bladder (bacterial cystitis) is good to excellent

• Prognosis for pets with complicated infection is determined by the prognosis for the underlying abnormality

Watch the video: How to prevent feline lower urinary tract disease FLUTD in your cat - Purina (July 2021).