Causes of Urinary Infections in Cats

Feline urinary infections are less frequent than canine infections, but can occur due to different types of bacteria, viruses or other factors. The urinary tract can get severely swollen and cause different symptoms and if left untreated, it can lead to bladder and urethra damage. Knowing the causes of urinary infections in cats can help you understand the disease and enable you to prevent future urinary infections.

Causes of Urinary Infections in Cats

Urinary infections in cats are also known as feline urinary tract disease or FLUTD and may be caused by a wide range of factors such as bacteria, viruses, tumors, bladder stones, abnormal pH of urine or congenital deformities.

FLUTD may also be idiopathic, so the causes are not known.

Viruses and Bacteria

The viruses and bacteria are the leading causes of urinary infections in cats. These bacteria or viruses may be normally present in the urine, but if they are eliminated, they won’t be able to multiply and cause an infection. However, the viruses and bacteria may also travel from the urethra to the urinary tract, causing inflammation.

The infections caused by viruses and bacteria can be treated with antibiotics, but may be prevented by giving the cat a healthy amount of fresh water.


Tumors in the urinary tract can also cause recurrent urinary infections. The tumors may disrupt the normal balance of the urinary tract and may lead to the accumulation and spreading of bacteria and viruses.

Bladder Stones 

Bladder stones can cause urinary tract infections. The bladder stones may be the result of an unsuitable diet and an increased intake of vitamins and minerals. The bladder stones may be flushed with water, dissolved with medication or may require surgery.

If not removed, the bladder stones will cause chronic FLUTD.

Abnormal pH of Urine 

The pH of the urine can contribute to urinary infections in felines. If the alkalinity or acidity of the urine is elevated, this can facilitate the bacterial reproduction.

Vegetarian diets can make the urine alkaline. An increased amount of proteins can increase the acidity of the urine.

Congenital Deformities

Congenital deformities of the urinary tract can facilitate the access of bacteria and viruses and lead to FLUTD. This can happen if the urethra is too short (which also explains why female cats have UTI more often than male cats) or if the bladder has an unusual location.

Contributing Factors 

There are also a few contributing factors that facilitate the occurrence of urinary tract infections in cats. These contributing factors may include:

  • Stress, which affects the immune system, making it more exposed to infections
  • Diet
  • Insufficient intake of water, which can facilitate the formation of bladder stones
  • Holding back the urine for too long, which can be due to stress, changes (i.e. of litter brand) or other emotional problems and will facilitate the gathering and multiplication of bacteria