Have you ever witnessed your cat struggling to go for a wee, popping in and out of the litter tray or passing small amounts of red coloured urine? These are all signs of Feline Lower Urinary Tract Disease (FLUTD).
Feline lower urinary tract disease (FLUTD) is a term describing conditions that can affect the urinary bladder and/or urethra (the lower urinary tract) of cats. There are a variety of causes including urethral plugs, anatomical issues and cancer. However in about 2/3 of cases there is no known cause and these are referred to as being Idiopathic, this is similar to human interstitial cystitis.
FLUTD is thought to affect around 1-3% of cats each year, so is among the more common diseases seen. Because of the diverse nature of the underlying causes, cats of any age, breed and gender can be affected by FLUTD, but in general, the disease is more common if the cat is:
- Middle-aged
- Stressed or nervous
- Neutered
- Over-weight
- Reluctant to exercise
- Is predominately an indoor cat
- Id fed a predominately dry diet
Cats with FLUTD often present with one or more signs. The cat may strain to pass urine or cry out if it is painful. There can be an increase in the frequency your cat tries to urinate and the urine can be bloodstained or found in odd places around the house rather than in the litter tray. Some cats will show behavioural changes and become aggressive or irritated and some will over groom and lick around the perineum as it is painful. In worst cases, they’re unable to pass any urine at all. If your cat is straining to urinate but is not passing any urine at all, it is an emergency and the cat should be taken to the vet straight away.
A number of different diseases may cause FLUTD, but the relative importance of these diseases varies between different countries and different populations of cats. Some of the more common causes include:
Urolithiasis – this is the term used to describe bladder stones. Just as in humans, cats can develop stones in their bladder. The two most common types of stone (determined by their composition) are ‘magnesium ammonium phosphate’ (or ‘struvite’) and ‘calcium oxalate’. These two types of stone account for 80-90% of cases of urolithiasis, but others may also be seen. Urolithiasis generally accounts for around 10-15% of cases of FLUTD.
Bacterial infections – bacterial cystitis (bacterial infection of the bladder) is the most common cause of lower urinary tract disease in many animals but is relatively uncommon in cats. It accounts for around 5-15% of all cases of FLUTD. Bacterial cystitis tends to be seen in older cats.
Urethral plugs – obstruction of the urethra in male cats may occur as the result of a ‘urethral plug’ – this is where there is an accumulation of proteins, cells, crystals and debris in the urine that combines together to form a plug that cannot be passed. Other causes of urethral obstruction include small bladder stones becoming lodged in the urethra or severe muscle spasm of the urethra (which can occur with severe inflammation/irritation).
Anatomical defects – sometimes a defect in the lower urinary tract may cause signs of disease. Most commonly this occurs with a narrowing affecting the urethra. If the urethra becomes damaged, fibrous tissue may form during the healing process which can significantly restrict the diameter of the urethra. When that happens, it may be difficult for cats to pass urine normally.
Tumours– although uncommon, particularly in older cats with signs of FLUTD, the possibility of a tumour (cancer) affecting the bladder or urethra needs to be considered. The most common bladder tumour is known as ‘transitional cell carcinoma’.
Idiopathic cystitis – despite the well-recognised causes of FLUTD, in the majority of cats (probably around 60-70%) no specific underlying disease can be identified, and these cats are classified as having ‘feline idiopathic cystitis’ or – a term that simply means inflammation of the bladder without a known cause.
In cats with signs of FLUTD, especially where signs are persistent, severe or where more than one episode of the disease occurs, it is important to try to identify which of the above reasons is causing it. The starting point of these investigations would be urinalysis, this means looking at a sample of urine to see if the pH is normal, if there are any red or white blood cells present and the sample would also be examined under the microscope to look for bacteria or abnormal cells or crystals.
In recurrent problems trying to visualise the bladder can give lots of information. We can do this by ultrasound to look at the bladder wall to see if it looks thick or irregular or to look for bladder stones. We can also visualise the bladder by X-ray. “Plain” X-rays can be used to look at the bladder and the urethra and then “Contrast Radiography” can be used. This is when we use a special contrast to help outline the urethra and the bladder and it can help in the diagnosis of some types of bladder stones, urethral strictures and tumours. This is a straightforward procedure but is done under an anaesthetic to avoid any discomfort for the cat and so that the cat does not move when the X-rays are taken. If a tumour is suspected then a biopsy might be taken this is done through a catheter placed into the bladder.
Cystitis in cats is a complex and challenging problem and in some cases will require lifelong management to reduce flares or recurrent problems, it can be distressing for both owner and cat but we are here to help.