Feline Lower Urinary Tract Disease FLUTD

Transcription

1 Feline Lower Urinary Tract Disease FLUTD What is Feline Lower Urinary Tract Disease? Feline lower urinary tract disease (FLUTD) describes a collection of conditions in cats that can affect the bladder and/or urethra (the passage from the bladder to the external opening). These conditions often show similar signs and other tests may need to be performed to find out the cause however, the vast majority of cases are idiopathic (which means that we cannot find the cause). Clinical signs of FLUTD Cats with FLUTD usually present with signs of difficulty and pain when urinating, urinating more often, blood in the urine, urination outside the litter-box and in inappropriate places or even complete obstruction to urine outflow (blocked cats). Blocked cats are usually very painful and will often howl in pain whilst trying unproductively to urinate. These cases are emergencies and can quickly progress to kidney failure with signs such as vomiting, being unsteady on their feet and even coma and death. It is thought that the annual incidence of FLUTD in British cats is around 1%. It is most commonly seen in middle-aged, over-weight cats, which take little exercise, use an indoor litter-box, have restricted access outside and eat a dry diet. Neutered cats are most susceptible to FLUTD and obstruction of the urinary tract is most likely in males.

2 Causes of FLUTD Below are two charts showing the causes of obstructive (blocked) and non-obstructive FLUTD. Idiopathic = no cause can be found. Urethral plugs = a combination of materials that block the urethra such as protein and cells that leak from the bladder wall and crystal material. Bladder stones = crystal structures that form in the bladder. Causes of obstructive FLUTD Idiopathic cystitis Urethral plug Bladder stones Bladder stones + bacterial infection Causes of non-obstructive FLUTD Idiopathic cystitis Bladder Stones Anatomical defects/cancer Behavioural problems Bacterial infection

3 1. Feline idiopathic cystitis. In the majority of cases of FLUTD no underlying cause can be found. However research has shown that changes between the bladder nerves, the protective layer that lines the bladder and the urine may be to blame. Bladder nerves can be stimulated either by the brain (due to stress) or by problems within the bladder (eg, inflammation, bladder stones, concentrated urine, infection, etc.). These nerves then cause pain and inflammation. When the brain causes the inflammation it is called neurogenic inflammation. One of the major triggers of idiopathic cystitis is stress. The thin layer of protective mucus that lines the bladder helps prevent bacteria and crystals sticking to the bladder wall. Defects in this may leave the bladder vulnerable and prone to inflammation. 2. Bladder stones. There are a few different types of bladder stones (uroliths) some types can be dissolved by using a specially designed diet but others have to be surgically removed. 3. Urethral plugs. Urethral plugs are important because they can cause urethral obstruction (blocked cats). They are made of a combination of protein (from the cells of the bladder and blood) and crystals. Plugs form in response to inflammation caused by any of the other causes of cystitis. 4. Infectious causes. Bacterial infection of the bladder is rare in cats and is usually secondary to other causes such as placing a urinary catheter, bladder stones or cancer. 5. Cancer Various cancers and growths can cause inflammation and so can lead to urethral plugs, bladder infections and stone growth. This can cause obstructive or non-obstructive FLUTD. The different causes of FLUTD may occur alone, or together. Obstruction usually results from urethral plugs, but may also be caused by small bladder stones, or from spasm of the urinary tract due to pain.

4 Diagnosis CARLISLE HOUSE, TOWNHEAD ROAD, DALSTON, CARLISLE, CUMBRIA, CA5 7JF Idiopathic cystitis is diagnosed by excluding all other causes of FLUTD. This can mean blood samples (to rule out systemic disease), urine samples, x-rays and ultrasound scans. In the case of obstructive FLUTD (blocked cats) the initial diagnosis is usually straight forward as the bladder is so large when it is palpated during abdominal examination. Management of FLUTD Obstructive FLUTD (blocked cat) is a medical emergency and is treated differently to nonobstructive FLUTD initially, though the long-term management is the same. When a cat s urethra becomes blocked whether by inflammation, spasm or stones the urine builds up in the bladder until it becomes full, this then creates a back pressure on the kidneys and can severely damage the kidneys causing kidney failure, coma and death. If a cat is suspected to be blocked veterinary attention should be sought immediately. The treatment may vary depending on how long the cat has been blocked and how severely ill it is but will usually involve blood tests to determine any damage to the kidneys and fluids to restore and support kidney function. The cat will then need to be anaesthetised so that a urinary catheter can be passed through the urethra past the blockage and into the bladder. In most cases the catheter will be left in place for 1-3 days until the blockage settles and so the patient will be hospitalised during this period. Unfortunately, whilst they have a urinary catheter, cats will not be able to control their urination and so they often end up with some urine staining on their coat. If a specific cause is found such as bladder stones then this will need to be addressed however, if no cause is found and a diagnosis of idiopathic cystitis is made then this will have to be managed.

5 The list of treatments that have been used for FLUTD is long but the current most successful approach to the management of FLUTD is described below. First line treatment: 1. Reduce stress. Stress is a major factor in FLUTD. Identified stressors include, abrupt changes in diet, environment, weather, overcrowding or addition of new pets or people to the household. Stress associated with urination can be particularly significant, e.g. an unsuitable position or content of the litter-box, competition for the litter-box, aggressive behaviour by other cats while the cat is trying to use the litter-box or when urinating outside. It is essential to reduce the level of stress to which a cat may be exposed. Providing a safe, clean area in which the cat can urinate, reducing overcrowding or bullying and reassuring the cat as much as possible may achieve this. Remember cats are not generally social creatures and living in a multi-cat house increases their chance of developing FLUTD. The majority of cats would generally prefer to live alone and it is only in forced situations where they will live together such as in our houses. Competition over resources can be stressful for cats. There should be more than one feeding station, watering station and litter tray per cat in the house. These should be placed in different areas through the house. As well as changing the cat s environment, there are certain products that will help reduce stress such as Feliway a synthetic feline pheromone and Zylkene, which mimics a substance found in milk. In some cases referral to a behaviourist may be needed. 2. Alter the content of the urine: The easiest way to alter the content of urine is to alter the diet. The single most important thing is to increase the cat s water intake, which dilutes any noxious components in the urine. The best way to do this is to feed a 100% wet diet, though some dry diets will also help if your cat will not eat wet food. Other ways to encourage water intake can be to use water fountains, which supply constant running water and have several fresh water containers available. 3. Repair the protective bladder lining layer: Some cats benefits from medications that supplement this layer. Supplements can be given by mouth or by injection.

6 Second line treatment: 1. Relief of urethral spasm: Certain drugs such as hypovase can help relax the muscles within the urethra. 2. Tricyclic antidepressants Tricyclic antidepressants (e.g. amitryptyline) can be used in very severe or chronic cases of FLUTD. These act as anti-depressants and also have direct effects on the bladder including anti-inflammatory and pain killing properties. 3. Pain killers Pain killers will help reduce the pain and should help reduce the signs of FLUTD. Treatment summary It is important to note that all current treatments for FLUTD are merely palliative. The best results are gained by instigating a number of changes, i.e., reducing stress, feeding a wet diet, replacing the lining layer and if necessary reducing urethral spasm or giving tricyclic antidepressants. In the majority of cases this, when tailored to the individual cat, will reduce or prevent further clinical signs. However, cat that have FLUTD once are likely to have repeat problems.