Bladder Infection in Cats

What is a bladder infection?

A bladder infection is an infection of the bladder, a hollow organ in the abdomen which collects and stores urine. Cystitis is the inflammation or infection of the bladder, so you may see cystitis, bacterial cystitis OR urinary tract infection used in place of or in conjunction with a bladder infection. Most cases of cystitis are idiopathic, which means the cause can not be determined. Bacterial infection of the cat’s bladder is less common in cats than it is in dogs. E. coli is the most common bacteria to infect the bladder.

There are different types of UTI depending on the location of the infection.

  • Cystitis – Infection of the bladder
  • Urethritis – Infection of the urethra
  • Pyelonephritis – Infection of the kidneys

Bladder infections are thought to develop when bacteria around the anus ascend into the urethra and the bladder.


Typical symptoms of bladder infection in cats may include:

  • Frequent urination, often only passing small amounts of urine (stranguria)
  • Blood in the urine (hematuria)
  • Urine that looks cloudy
  • Pain while urinating (dysuria)
  • Excessive genital licking
  • Urinating outside of the litter box
  • Foul-smelling urine


Your veterinarian will perform a complete physical examination of your cat and obtain a medical history from you. He may wish to run some tests to determine if the UTI is the result of a bacterial infection or idiopathic. Your cat may display pain when the vet palpitates the abdomen, and he may feel a thickening of the bladder.

As the symptoms of all types of UTI are very similar, your veterinarian will want to establish if the bladder is infected with bacteria or if the cause is idiopathic.

Diagnostic workup:

  • Urinalysis: A test of the cat’s urine to check for the presence of red and white blood cells and bacteria.
  • Bacterial culture and sensitivity: A diagnostic test to determine which antibiotic will be the most effective against a microorganism. A urine sample is obtained by cystocentesis (to ensure there has been no contamination) and sent to a laboratory where cultured, forming a bacterial lawn. Filter paper that has been impregnated with antimicrobial drugs are placed on the bacterial lawn to determine the most effective antibiotic. E. coli is the most common bacteria to infect the cat’s bladder; other bacteria include Proteus, Staphylococcus, and Streptococcus.
  • Imaging studies: Persistent or recurrent bladder infections may warrant an abdominal x-ray or ultrasound to look for the presence of calculi in the bladder.


Oral antibiotics will be prescribed for two weeks in cats with acute bladder infections. Bacterial culture and sensitivity will be recommended for cats with chronic bladder infections to determine the most effective antibiotic.

Home care

Home care is important. Try to encourage your cat to drink water and/or switch the cat to a wet diet that has a higher water content than dry food. Ensure there are enough litter trays to avoid cats holding onto the urine for longer than necessary. Longhaired cats with repeated bouts of bladder infections may benefit from a clip around the anal region.


  • Julia Wilson, 'Cat World' Founder

    Julia Wilson is the founder of Cat-World, and has researched and written over 1,000 articles about cats. She is a cat expert with over 20 years of experience writing about a wide range of cat topics, with a special interest in cat health, welfare and preventative care. Julia lives in Sydney with her family, four cats and two dogs. Full author bio