Feline idiopathic cystitis.txt

Feline idiopathic cystitis

Signs and symptoms
Feline idiopathic cystitis begins as an acute non-obstructive episode and is self-limiting in about 85% of cases, resolving itself in a week.  In approximately 15% of cases, it can escalate into an obstructive episode (“blocked cat”) which can be life-threatening for a male cat.  The symptoms for both a non-obstructive and an obstructive episode are usually very similar and a careful § differential diagnosis is necessary to distinguish between the two.
Non-obstructive FIC
The vast majority of FIC cases are non-obstructive. In the case of non-obstructive FIC, the underlying inflammatory process has begun but the disease has not progressed to the extent that it prevents urination (ie there is no obstruction of the urethra).  The cat's lower urinary tract is inflamed and the urethral passage may have narrowed due to swelling but it remains open and he can urinate to varying degrees, albeit in discomfort. Clinical signs apparent during an acute episode may include:
Obstructive FIC (“the blocked cat”)
If the acute flare-up of non-obstructive FIC has not resolved itself, it can progress to an obstructive episode in a small number of cases.  This is where the male urethra can become partially or fully blocked. Female cats have a larger urethra and rarely become blocked. The following clinical signs may be observed:
A full obstruction is a medical emergency and must be relieved by a vet immediately. Partial obstructions should also be investigated as soon as possible as they are unlikely to resolve themselves and can escalate to full obstruction. Early intervention leads to better prognoses.
Differential diagnosis of obstructive and non-obstructive cases
The clinical signs in both obstructive and non-obstructive cases can appear very similar to the owner.  In particular, stranguria (when a cat strains when urinating), is observed in both cases.  The differences between the two cases are discussed below.
A vet will often distinguish between obstructive and non-obstructive cases by checking the cat's bladder.  A normal, healthy bladder will be semi-full of urine and soft to the touch, like a partially filled balloon.  However an inflamed bladder (suggestive of cystitis) will have thickened walls. The bladder muscles have become inflamed and irritated, provoking an involuntary urge to frequently urinate.  This manifests as the straining (i.e. stranguria) observed as the cat attempts to void.  As long as the cat is able to void (even if volumes may be small), the bladder will present as small on examination (i.e. very little urine in it due to frequent emptying) and this is suggestive of non-obstructive cystitis.
However, if the bladder remains distended (i.e. full of urine) then the cat is either unable or unwilling to void. The vet will palpate the bladder in an attempt to produce a free-flowing, continuous stream of urine. If this does not occur, a potential obstruction will be suspected and further diagnostics like urinalysis, ultrasound and x-rays may be warranted. However even an inability to express a distended bladder is not definitive for blockage as the cat may simply actively resist the vet's intervention by "pushing back," due to anxiety or a desire to avoid a painful urination.
A less frequently seen intermediate case is where the bladder presents as normal but is accompanied by straining and frequent attempts at urination. This suggests a possible intermittent spasming of the urethra (ie an "on-off" § functional block) which allows voiding at times when the cat is able to relax himself, but prevents it when the urethral muscles tense involuntarily again.  In these instances, the vet may sedate the cat, which relaxes the entire urinary musculature, causing spontaneous urination.

Differential diagnosis of obstructive and non-obstructive cases
The clinical signs in both obstructive and non-obstructive cases can appear very similar to the owner.  In particular, stranguria (when a cat strains when urinating), is observed in both cases.  The differences between the two cases are discussed below.
A vet will often distinguish between obstructive and non-obstructive cases by checking the cat's bladder.  A normal, healthy bladder will be semi-full of urine and soft to the touch, like a partially filled balloon.  However an inflamed bladder (suggestive of cystitis) will have thickened walls. The bladder muscles have become inflamed and irritated, provoking an involuntary urge to frequently urinate.  This manifests as the straining (i.e. stranguria) observed as the cat attempts to void.  As long as the cat is able to void (even if volumes may be small), the bladder will present as small on examination (i.e. very little urine in it due to frequent emptying) and this is suggestive of non-obstructive cystitis.
However, if the bladder remains distended (i.e. full of urine) then the cat is either unable or unwilling to void. The vet will palpate the bladder in an attempt to produce a free-flowing, continuous stream of urine. If this does not occur, a potential obstruction will be suspected and further diagnostics like urinalysis, ultrasound and x-rays may be warranted. However even an inability to express a distended bladder is not definitive for blockage as the cat may simply actively resist the vet's intervention by "pushing back," due to anxiety or a desire to avoid a painful urination.
A less frequently seen intermediate case is where the bladder presents as normal but is accompanied by straining and frequent attempts at urination. This suggests a possible intermittent spasming of the urethra (ie an "on-off" § functional block) which allows voiding at times when the cat is able to relax himself, but prevents it when the urethral muscles tense involuntarily again.  In these instances, the vet may sedate the cat, which relaxes the entire urinary musculature, causing spontaneous urination.

Treatment of an acute episode
First and foremost, the cat must be kept well hydrated with wet food/soups/broth/increased water intake.  This keeps the urine dilute, reducing pain and inflammation, as well as encouraging urination to keep the bladder clear of debris thereby reducing the risk of a § mechanical blockage (dry food must therefore be avoided).  Since the underlying process is inflammation of the bladder, one of the most frequent pharmacological treatments is to administer anti-inflammatory medication.  NSAIDs such as meloxicam or robenacoxib are commonly prescribed to control this (provided there are no renal or gastric contraindications).  The condition is intensely painful and analgesia (via NSAID or opiates such as buprenorphine) is essential to reduce discomfort and control further stress (which could in turn trigger further inflammation).  In the case of a male cat, spasmolytics such as prazosin in combination with dantrolene may also be prescribed to control painful urethral spasms and prevent the risk of a § functional blockage.
Since stress is considered to be a key aggravator in triggering cases of FIC, the most important non-pharmacological/non-dietary intervention is to modify the cat's environment to minimise stressors and improve general well-being (see § environmental modification below). In addition, calming supplements such as tryptophan or alpha-casozepine can also be added to food to improve mood and relaxation.
Oral supplements to reinstate the protective glycosaminoglycan (GAG) layer of the bladder (often deficient in cats suffering from FIC) may also be considered.  Supplementation with antioxidants and essential fatty acids such as high quality fish oil have also been shown to reduce the severity of the episode.  The veterinarian may also use a urine sample from the cat to carry out urinalysis to test for the § presence of crystals which could aggravate the condition (see below).
Within a week most cats should improve spontaneously as the inflammation subsides. However, it is essential to monitor urine output (and compare it to moisture intake) throughout the day, every day, to watch for incipient signs of blocking until the inflammation subsides and the cat returns to good health.  Any presumed non-obstructive case which does not resolve itself with 7 days should be suspect for obstruction and investigated further.

Treatment of an acute episode
Veterinary attention is essential if urine does not pass at all as the bladder could rupture and there is risk of death within 72 hours.  The vet will usually attempt to relieve the blockage with a catheter, to drain the backed-up urine  and flush the bladder out of any sediment (this may include crystals).  This is an invasive, delicate procedure which will require either heavy sedation or general anaesthetic.  The cat may then be hospitalised with the catheter in place and hydration administered intravenously to encourage healthy urination and good kidney function for up to 3 days.  While the catheter is in place, intravesical instillation (which is also used to treat human interstitial cystitis) may also be administered to repair the compromised bladder lining. When the catheter is removed, the cat must be able to show he can urinate with good function before he can be discharged.  With this proviso, he can return home and the anti-inflammatory and anti-spasm medication indicated for non-obstructive cases will be prescribed, as well as oral supplements to calm the cat and replenish the protective bladder lining (see above).
Even after the cat is unblocked, the underlying inflammatory syndrome will continue for some days at home (particularly since the catheter itself will have irritated the urethra).  Therefore, some of the clinical signs for non-obstructive FIC may still be apparent post-discharge until the inflammation subsides and cat has fully recovered (e.g. frequent voiding, blood in urine, possible leaking).  However medication should alleviate the severity and discomfort as well as assisting recovery.  The owner must focus above all on good hydration (from a wet food diet if the cat will accept it) and frequent urination to keep the bladder clear.  Wet prescription diets may be recommended but if the cat refuses this (cats often avoid eating unfamiliar food when stressed), any high quality, high moisture, high animal protein wet food which the cat finds appealing may be administered. A urinary acidifier (e.g. DL-Methionine) may be added to the latter to prevent struvite crystal formation but as animal protein is already acidic, it is not strictly necessary. In any case, excessive acidification should be balanced against the risk that it could irritate the inflamed bladder wall (possibly triggering recrudescence ie a further acute attack), as well as encouraging calcium oxalate crystal formation. An acidifier should never be added to prescription urinary food as this has already been acidified. Acidification or prescription foods are always secondary to the first priority of overall, general hydration from any wet food the cat finds palatable.  Dry food of any sort (including prescription dry food) must be avoided.
Environmental modification to reduce stress, itself suspected to be one of the principal causes of FIC, must also be considered (see below) as the risk of re-blocking is highest within the first week after catheterisation.
Secondary bacterial infection (UTI) after an obstructive episode
Whereas primary feline urinary tract infections are rare in younger male cats, when a cat suffers an obstructive episode of FIC which has involved catheterisation and/or the symptomatic presence of crystals, then a secondary urinary tract infection becomes more likely as a follow-on complication.  The symptoms of bacterial infection in the lower urinary tract are very similar to those for non-obstructive FIC (ie straining, blood in urine etc) and a urine test with cultures will be needed to detect if an infection is present.  Treatment is usually effective with antibiotics once the result of the urine culture identifies the precise bacteria involved in the infection.  D-mannose (which is also anti-inflammatory) is also used by some pet owners as a natural alternative to antibiotic treatment although this may be less targeted and specific than prescribed antibiotics following a urine culture.