Urinary tract infection (UTI) in cats

Summary

What is urinary tract infection (UTI)?

A urinary tract infection (UTI) is an infection that occurs anywhere along the urinary tract. The upper urinary tract consists of both kidneys which produce urine which is conveyed to the bladder via the ureters. The bladder is classed as ‘lower urinary tract’ and is emptied via the urethra. Typically, UTIs are ascending, meaning bacteria from the skin or the gastrointestinal tract ascend the urethra and lodge in the bladder.

Urine in the bladder is usually sterile, with presence of bacteria accompanied by white and red blood cells noted in the urine indicative of an infection. Some cats can have ‘subclinical bacteriuria’ where bacteria are noted in the urine but there are no other signs or abnormalities associated with infection.

Expert advice from Dr Felicia:

Feline urinary issues are usually easy to identify in indoor cats but more difficult in outdoor cats as owners generally have less familiarity with their cat’s toileting habits. Urinary issues may crop up in early life for some cats that may be more prone to stress/anxiety, but many of these cases may not be due to a true UTI where an infection is present, rather a sterile ‘stress’ cystitis.

UTIs are uncommon in young cats, with higher incidence in older cats, particularly those over the age of 10 years. UTIs in male cats are far less common but can be more dangerous due to their narrower urethra compared with female cats. Bacterial UTIs can cause a change in the urine pH, and alkaline urine can lead to the formation of crystals, which can become lodged in the narrow urethra of a male cat, causing a blockage. A blocked urethra is a medical emergency and requires immediate veterinary treatment.

Infection of the bladder by bacteria is also known as “bacterial cystitis.” Sometimes the bacteria continue to ascend from the bladder to the kidneys, causing a kidney infection called “pyelonephritis”. Some cats will develop bladder stones (“uroliths”) with or without a UTI, which creates additional health issues. Recurrent urinary tract infections can contribute to the development of  feline lower urinary tract disease (FLUTD).

Cost of urinary tract disorders in cats

Urinary tract disorders were the second most common health issue experienced by cats in 2024, according to PetSure claims data.

^ØBased on PetSure claims data, 2024 calendar year. Reimbursement for these claims under a pet insurance policy would be subject to limits, such as annual benefit limits or sub-limits, benefit percentage, applicable waiting periods and any applicable excess. Cover is subject to the policy terms and conditions. You should consider the relevant Product Disclosure Statement or policy wording available from the relevant provider. Please note that values calculated are based on all claims for that condition and medically related conditions in each calendar year.

Because it is difficult to predict the costs of veterinary care, it can help to have measures in place to help prepare for the unexpected. Pet insurance can help by covering a portion of the eligible vet bill if the unexpected does happen.

Get a quote for 2 months free pet insurance for your puppy or kitten in their first year.

Symptoms of urinary tract infection (UTI) in cats

Cats often demonstrate painful or difficult urination in multiple ways which may signify a UTI. However, these can vary widely between cats, ranging from mild to extremely severe. Additionally, cats are often ‘asymptomatic’ as they may mask their symptoms, making it difficult for their owners to detect any signs except for a non-specific change in behaviour or personality.

Some of the typical observable symptoms of a UTI are:

• Passing small amounts of urine (pollakiuria)
• Abnormally frequent attempts to urinate
• Straining to urinate (stranguria)
• Blood in the urine (haematuria)
• Crying out or whining while urinating
• Difficulty urinating (dysuria)
• Incontinence or dribbling of urine
• Cloudy urine
• Licking / grooming the genitals excessively
• Stronger than normal urine odour
• Urinating outside the litter box and in other inappropriate places
• Visiting the litter box more often than usual
• Spending a longer than usual amount of time in the litter box
• Visiting the litter box but not leaving any deposits
• Drinking more water than usual
• Not eating as much as usual (inappetence; anorexia)
• Fever
• Behavioural changes, such as seeming withdrawn, depressed, irritable or lethargic

Expert advice from Dr Felicia:

If the wet patches in the litter are smaller than usual, the litter needs cleaning more often, your cat is constantly in and out of the tray or vocalising when in the tray, there’s probably a urinary issue that needs to be checked.

Causes of urinary tract infection (UTI) in cats 

Bacteria, fungi, parasites and even viruses can cause infections of a cat’s urinary tract.  These microorganisms enter the body via the urinary tract, travel up the urethra and typically to  bladder, causing the bladder to become inflamed and painful and resulting in a change in urinary habits.

The primary bacteria involved in feline UTIs are Escherichia coli (E. coli), Staphylococcus, Proteus, Chlamydia, Enterococcus, Klebsiella, Streptococcus, Enterobacter and Pseudomonas, with E. coli being the single most common pathogen in both acute and recurrent UTI in dogs and cats. Occasionally, microorganisms other than bacteria are responsible, including mycoplasma, viruses, algae and fungi, but this is rare.

Bacteria simply ascending the cat’s urinary tract without any reason or predisposing condition is uncommon, but not impossible. Some cats have “idiopathic” UTIs, meaning that the cause of their infection is unknown.

In most cases, the predisposing or contributing factors for cat UTI may be one or more of the following:

• Age plays a role in the development of a cat UTI, with the incidence being much higher in older female cats, particularly those over the age of 10 years; in young cats, incidence of UTI is low.
• Cats with compromised immune systems or other health complications have reduced defences for fighting infections have a greater incidence of UTI. Underlying medical conditions associated with feline UTIs include:
  • Diabetes mellitus
  • Chronic kidney disease
  • Hyperthyroidism
  • Feline leukemia virus (FeLV)
  • Feline immunodeficiency virus (FIV) 
• Cats with bladder stones (uroliths) are prone to recurrent UTIs; it is essential that bladder stones are removed or dissolved to restore bladder health.
• Stress is thought to play a role in developing a cat UTI; cats are typically creatures of habit and easily become stressed from a change in routine, a new baby or pet, or a move to a different house.
• Elevated urine pH from any cause creates a bladder environment that is primed for bacterial overgrowth.
• Certain allergies (also called “immune-mediated hypersensitivities”) can contribute to bladder irritation, inflammation and infection.
• A more recent cause of recurrent UTI is antimicrobial resistance.
• Long-term administration of steroid medications can suppress the immune system, increasing a cat’s chances of contracting urinary tract infections.
• Free-roaming outdoor cats are more likely to develop a persistent UTI, largely because they tend to have veterinary check-ups less frequently than indoor cats, and owners are less likely to observe any symptoms.

Expert advice from Dr Felicia:

All cats at the vet for urinary disease should have some assessment for underlying and contributing causes for their UTI. Without addressing these, the UTIs may become resistant, recurrent or even cause systemic illness.

How is urinary tract infection (UTI) in cats diagnosed?

Cat owners should schedule an appointment with their veterinarian if they notice any unusual changes in the cat’s urinary habits. A thorough history, physical examination and potentially bloodwork may help identify underlying medical and/or anatomic conditions that predispose cats to developing UTIs which may have specific treatments to prevent persistent or recurrent infections, on top of treating the infection itself.

Since not all cats show signs specific to the urinary system, your vet may suggest taking a urine sample to identify if an infection is present in the absence of specific urinary signs if your cat is behaving as they would normally. Some cats will have a subclinical bacteriuria and usually in the absence of inflammatory cells or signs of urinary disease these should not be treated as a UTI. From discussing your cat’s history and looking at a urine sample your vet will be able to make an assessment on whether an infection or subclinical bacteriuria is present.

Expert advice from Dr Felicia:

The most helpful thing is to bring your cat to the visit with as full a bladder as your can manage. You may be able to achieve this by restricting access to the outdoors, or to the tray for an hour or two prior to the visit. Cats can also spend some time at the hospital to accumulate more urine for sampling when this is not feasible prior to the visit.

Diagnosing a bladder infection is relatively straightforward. If your vet can palpable your cat’s bladder on physical examination, a uncontaminated urine sample can be taken directly from the bladder with a needle and syringe (cystocentesis) for a ‘urinalysis’. The urine is checked for specific gravity (concentration), pH, presence of glucose, ketones, bilirubin, then examined under microscope to assess if bacteria and inflammatory cells are present. If bacteria and large numbers of inflammatory cells are observed, a UTI is diagnosed. Ideally a urine culture is performed in the laboratory to identify the specific type of bacteria present. Sensitivity testing is usually also performed to work out the most effective antibiotic for treatment. This process can take up to a week, so usually an empirical choice will be made in the meantime while awaiting confirmation from the culture.

Expert advice from Dr Felicia:

For cats who are unlikely to tolerate restraint for the collection of urine, your vet may be able to give you some medication to be given at home to help alleviate some vet visit anxiety for your cat.

If there are no bacteria in the urine sample, abdominal x-rays or ultrasound may be recommended to look for bladder stones. Cats with bladder stones are prone to recurrent UTIs, hence the importance of getting a complete diagnosis whenever there is evidence of disease in the urinary tract. Bladder stones will need to be removed or dissolved to restore bladder health.

Other tests may be performed to diagnose underlying or contributing medical conditions, for example:

• Blood tests, including a complete blood count and serum chemistry profile, may reveal underlying conditions such as kidney disease, diabetes or hyperthyroidism.
• For recurrent or persistent UTIs, abdominal radiographs (x-rays) and ultrasonography can be helpful to assess the size and structure of the kidneys, ureters, bladder and urethra and to reveal abnormalities such as stones (uroliths), tumours and enlarged prostate glands.
• Radiographic contrast studies may be performed to identify kidney or bladder stones or masses that are obstructing the output of urine.

Prognosis

The prognosis for cats with uncomplicated bacterial UTI is excellent, provided they are diagnosed and treated promptly and appropriately. The prognosis for cats that have bacterial UTI caused by a predisposing medical condition is quite variable and depends largely upon correct identification and treatment of the underlying disorder.

If untreated, a cat UTI can lead to more serious problems, including damage to the tissues of the urinary tract. Additionally, for immunosuppressed, older cats, the contributing microorganisms can proliferate and infect other areas, including the kidneys and ureters, and the infection can potentially spread through the cat’s blood. This is called “sepsis” and is a life-threatening medical emergency. Since urinary tract infections are less common in males, any UTI in a male cat is considered serious and a favourable prognosis necessitates immediate medical attention.

Because it is difficult to predict the costs of veterinary care, it can help to have measures in place to help prepare for the unexpected. Pet insurance can help by covering a portion of the eligible vet bill if the unexpected does happen.

Get a quick quote

Treatment for urinary tract infection (UTI) in cats 

The primary goals of treating feline UTIs are to address the organisms that are causing the infection, relieve the cat’s symptoms and prevent complications. If any predisposing medical or anatomical abnormalities have been identified, these also need to be addressed. Prevention of further UTIs is another goal of treatment, as a cat that has had one UTI is more likely to have another in the future.

Typical treatment includes:

Antimicrobials / antibiotics:

• Initially, the veterinarian will prescribe an antibiotic that is commonly used for treating UTIs to provide immediate relief to the cat while awaiting results of urine culture and sensitivity.
• Once the culture and sensitivity results are received, a different antibiotic that targets the identified bacteria may be prescribed if needed.
• After the course of antibiotics is given, another urinalysis is performed to check if the infection has resolved. 

Dietary modification:

• The cat’s diet may be a contributing factor; additionally, diabetic and overweight cats are at greater risk of urinary tract disease.
• The vet may recommend dietary changes that will help to prevent UTIs and the formation of crystals in the bladder. Often wet food may be more beneficial for increasing the amount of urine produced.
• Specific nutritional formulations can support lower urinary tract health may be prescribed.

Expert advice from Dr Felicia:

Some cats can be difficult to medicate. If you have concerns about giving your cat medication, your vet may be able to discuss alternative formats (such as liquid, rather than a tablet), to ensure your cat receives the treatment they need.

 Preventative measures:

• Schedule annual check-ups with the vet that include a routine urinalysis.
• Pay attention to you cat’s urinary habits so that any symptoms of UTI can be promptly identified.
• Keep the litter box scrupulously clean.
• Minimise stress – for example, play with the cat, allow plenty of exercise, provide perches and hiding places.
• Allow free access to fresh water and consider the feeding of wet food, which will promote hydration and help flush infectious organisms out of the urinary tract.

Expert advice from Dr Felicia:

Regular check ups and urine screening for cats over the age of ten and especially those with other illnesses such as chronic kidney disease, diabetes, hyperthyroidism can help with early interventions for infections or monitoring of subclinical bacteriuria.

In conclusion

A urinary tract infection, or “UTI”, is an infection that can develop anywhere along the cat’s urinary tract. It is typically caused by bacteria that travel up the cat’s urethra and lodge in the bladder. UTIs can occur in cats of all ages but are more common in females, especially those ten years and older. Cats with UTIs may be asymptomatic or may have symptoms relating to difficulty in urinating, such as urinating outside the litter box or frequent and painful urination.

Diagnosis is usually made based on the results of a urinalysis. If a UTI is detected early, treatment can be a simple process, entailing a course of antibiotic medication and possible dietary changes. Untreated UTIs can lead to complications which may be life-threatening, while recurrent UTIs can greatly increase the development of feline lower urinary tract disease (FLUTD). Preventative measures are important for lowering the risk of future infections.

More information

• https://bowwowinsurance.com.au/pet-care/diseases-conditions/feline-lower-urinary-tract-disease-flutd/
• https://vcahospitals.com/know-your-pet/urinary-tract-infections-utis-in-cats
• https://www.petmd.com/blogs/thedailyvet/jcoates/urinary/2011/july/feline_urinary_issues-treating_urinary_tract_infections-11357