Title: Feline idiopathic cystitis

{{short description|Inflammation of the urinary tract in cats}}
{{About|cystitis in cats (or '''feline idiopathic cystitis''') which is a sterile condition and does '''not''' involve a primary urinary tract infection|the human urinary disease, '''cystitis''', which always involves a bacterial infection|urinary tract infection}}

'''Feline idiopathic cystitis (FIC)''' or '''feline interstitial cystitis''' or '''cystitis in cats''', is one of the most frequently observed forms of [[feline lower urinary tract disease]] (FLUTD). Feline cystitis means &quot;inflammation of the bladder in cats&quot;.  The term [[idiopathic disease|''idiopathic'']] means unknown cause; however, certain behaviours have been known to aggravate the illness once it has been initiated. It can affect both males and females of any [[breed]] of [[cat]]. It is more commonly found in female cats; however, when males do exhibit cystitis, it is usually more dangerous.&lt;ref name=&quot;Cannon_2006&quot;&gt;{{cite book | vauthors = Cannon M, Forster-van Hijfte M | date = 2006 | title = Feline Medicine: a practical guide for veterinary nurses and technicians | url = https://books.google.com/books?id=Jv_AG8XJ_ZEC&amp;pg=PA146 | publisher = Elsevier Sciences | isbn = 9780750688277 }}&lt;/ref&gt;

Despite the shared terminology, cases of feline idiopathic cystitis, as opposed to human cystitis episodes, are sterile. In other words, they do '''not''' involve a primary bacterial infection.  If upon investigation the inflammation of the feline bladder is in fact found to be the result of an infection, then it is described as a feline [[urinary tract infection]] (UTI) or less commonly, feline bacterial cystitis.  In cats under the age of 10 years old, FIC is the most common urinary disease seen in cats and UTIs are very rarely encountered.&lt;ref&gt;{{cite web | url = https://www.purina.co.uk/cats/health-and-nutrition/symptoms-to-watch-out-for/urinary-tract-health | title = Cat Urinary Tract Problems | publisher = Purina }}&lt;/ref&gt;&lt;ref name=&quot;pmid27102690&quot;&gt;{{cite journal | vauthors = Longstaff L, Gruffydd-Jones TJ, Buffington CT, Casey RA, Murray JK | title = Owner-reported lower urinary tract signs in a cohort of young cats | journal = Journal of Feline Medicine and Surgery | volume = 19 | issue = 6 | pages = 609–618 | date = June 2017 | pmid = 27102690 | doi = 10.1177/1098612X16643123 | url = https://research-information.bris.ac.uk/en/publications/a703d62a-8b70-4bf8-94be-5fd215db58f5 | s2cid = 206693086 | hdl = 1983/a703d62a-8b70-4bf8-94be-5fd215db58f5 | hdl-access = free | pmc = 11128815 }}&lt;/ref&gt; However, in cats over 10 years of age, UTIs are much more common and idiopathic cases are much less frequently observed.&lt;ref name=&quot;Chew_2007&quot;&gt;{{Cite journal| vauthors = Chew D |date=2007-08-19|title=Non-obstructive Idiopathic/Interstitial Cystitis in Cats: Thinking Outside the (Litter) Box|url=http://www.vin.com/doc/?id=6695884|journal=World Small Animal Veterinary Association World Congress Proceedings, 2007}}&lt;/ref&gt;  On the other hand, FIC does show several similarities to an analogous disease in humans called [[interstitial cystitis|bladder pain syndrome]].&lt;ref name=&quot;Cook_2013&quot;&gt;{{Cite journal | vauthors = Cook JL, Arnoczky SP |date=2015-03-30|title=World Small Animal Veterinary Association World Congress Proceedings, 2013|url=http://www.vin.com/doc/?id=6699733|website=VIN.com}}&lt;/ref&gt;&lt;ref name=&quot;pmid24257070&quot;&gt;{{cite journal | vauthors = Treutlein G, Deeg CA, Hauck SM, Amann B, Hartmann K, Dorsch R | title = Follow-up protein profiles in urine samples during the course of obstructive feline idiopathic cystitis | journal = Veterinary Journal | volume = 198 | issue = 3 | pages = 625–30 | date = December 2013 | pmid = 24257070 | doi = 10.1016/j.tvjl.2013.09.015 }}&lt;/ref&gt;

==Signs and symptoms==
Feline idiopathic cystitis begins as an [[acute (medicine)|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 (&quot;blocked cat&quot;) which can be life-threatening for a male cat.&lt;ref name=&quot;Cook_2013&quot; /&gt;  The symptoms for both a non-obstructive and an obstructive episode are usually very similar and a careful [[#Differential diagnosis of obstructive and non-obstructive cases|§ differential diagnosis]] is necessary to distinguish between the two. 
[[File:Suspected interaction of clinical signs in Feline Idiopathic Cystitis (FIC).pdf|thumb|Suspected interaction of clinical signs in FIC]]

===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 (i.e. the cat has not &quot;blocked&quot;). Non-obstructive FIC usually resolves spontaneously within 5 to 7 days regardless of treatment.&lt;ref&gt;{{Cite journal |last1=James L. Cook1 |first1=D. V. M. |last2=Steven P. Arnoczky2 |first2=D. V. M. |date=2015-03-30 |title=World Small Animal Veterinary Association World Congress Proceedings, 2013 |url=http://www.vin.com/doc/?id=6699733 |website=VIN.com}}&lt;/ref&gt; The cat's lower urinary tract is inflamed and the urethral passage may have narrowed due to swelling but it remains open (&quot;patent&quot;) and it can urinate to varying degrees, albeit in discomfort. Clinical signs apparent during an [[acute (medicine)|acute]] episode may include:

* Frequent trips to the litter box, possibly with straining due to inflammation triggering urethral spasms.
*Sensation of incomplete voiding.
* Production of small volumes of urine.
*Possible presence of [[blood]] in the urine&lt;ref&gt;{{cite book | vauthors = Sands D | title = Cats 500 questions answered | year = 2005 | url = https://books.google.com/books?id=A1VRa4_MI6kC&amp;pg=PA218 | publisher = Barnes and Noble | isbn = 9780600611790 }}&lt;/ref&gt; due to [[glomerulation]] or [[Hunner's ulcer]]s.&lt;ref&gt;{{cite journal | vauthors = Clasper M | title = A case of interstitial cystitis and Hunner's ulcer in a domestic shorthaired cat | journal = New Zealand Veterinary Journal | volume = 38 | issue = 4 | pages = 158–60 | date = December 1990 | pmid = 16031604 | doi = 10.1080/00480169.1990.35644 }}&lt;/ref&gt;
* Odorous urine.
* Irritability.
* Lack of interest in normal activities.
* Hiding in a dark, quiet location (hiding is part of the cat's stress coping mechanism and should not be interfered with unnecessarily).
* Experiencing pain during the act of urination, characterized by vocalisation. However, since cats are evolutionarily adept at hiding their pain, vocalising, crying, or any other audible cue may not always be observed.{{Citation needed|date=January 2023}}
*Reluctance or refusal to urinate due to the pain of excretion. This causes urine to collect in the bladder, similar to that in an obstructive episode. Stagnant urine can become concentrated which promotes [[Feline idiopathic cystitis#The role of crystals in obstructive FIC|§ crystal formation]], aggravating the risk of [[Feline idiopathic cystitis#Mechanical blockage|§ mechanical obstruction]] (see below).  
*Urine leakage if the bladder is not emptied due to [[overflow incontinence]] and/or [[Detrusor muscle|detrusor]] malfunction (also seen in obstructive episodes).  Leaking of urine can also occur due to inflammation of the urinary musculature.
* Loss of appetite and/or refusal to drink due to pain.
* Adopting unusual postures to cope with the pain.
* Urinating in places other than the litter box as the cat associates the pain of urination with the litter box.
* Licking/over-grooming the genital area.
* Lying on cold surfaces, such as tile floors or in showers, in an attempt to relieve pain.

===Obstructive FIC (&quot;the blocked cat&quot;)===
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 [[urethra]] can become partially or fully blocked.  This is a particular risk for males since they have narrow urethras.  Female cats have a larger urethra and rarely become blocked. The following clinical signs may be observed:

* In the case of full obstruction, unproductive and painful straining with either no urine passed '''at all''' or isolated drops produced (&quot;spotting&quot;) despite frequent trips to the litter box.
* [[Urinary retention]] due to incomplete voiding as a result of the obstruction. This means the bladder fills but cannot empty, causing bladder distension (the bladder will feel large and tense).&lt;ref name=&quot;:4&quot;&gt;{{Cite journal| vauthors = Bovens C |date = 2011 |title=Feline Urinary Tract Disease: A diagnostic approach|url=https://www.langfordvets.co.uk/media/1260/feline-update-autumn-2011-revised-030713.pdf|journal=Feline Update (Langford Feline Centre at the University of Bristol)}}&lt;/ref&gt;
* Involuntary leaking of urine due to paradoxical incontinence (when drops of urine leak past the obstruction due to pressure building up in the distended bladder).&lt;ref&gt;{{Cite web|title=Urinary incontinence in cats {{!}} Vetlexicon Felis from Vetstream {{!}} Definitive Veterinary Intelligence|url=https://www.vetstream.com/treat/felis/diseases/urinary-incontinence|access-date=2020-10-14|website=www.vetstream.com}}&lt;/ref&gt;
* Increased pain caused by stagnant urine collecting in the bladder, aggravating underlying inflammation, as well as the increasing distension of the bladder.
* Increased agitation and restlessness. 
* Possible vomiting. 
* Eventual lethargy and listlessness if a fully obstructive episode progresses, causing risk to life.

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===
{{see also|Differential diagnosis}}
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.   
{| class=&quot;wikitable&quot;
|+Clinical features of obstructive and non-obstructive stranguria&lt;ref&gt;{{Cite book|title=BSAVA manual of canine and feline nephrology and urology|date=2017|others=Jonathan, MRCVS Elliott, Gregory F. Grauer, Jodi L. Westropp, British Small Animal Veterinary Association|isbn=978-1-910443-35-4|edition=Third|location=Gloucester|oclc=1011666365}}&lt;/ref&gt;
!'''Process'''
!'''Frequency'''
'''of urination'''
!'''Volume of'''
'''urination'''
!'''Bladder'''
'''size'''
!'''Systemically'''
'''unwell'''
|-
|Non-obstructive stranguria
|Increased
|Decreased
|Small
|Unlikely
|-
|Obstructive stranguria
|Increased
|Decreased 
to none
|Large
|Unlikely
|}
A vet will often distinguish between obstructive and non-obstructive cases by checking the cat's bladder.&lt;ref name=&quot;Chew_2007&quot; /&gt;&lt;ref name=&quot;:4&quot; /&gt;  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 can manifest 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 &quot;small&quot; on examination (i.e. very little urine in it due to frequent emptying).  This suggests the cat has not (yet) blocked.

However, if the bladder remains distended (i.e. full of urine), it is considered &quot;large&quot; and together with the obstructive clinical signs listed above, could suggest blockage. The vet will [[Palpation|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]], [[medical ultrasound|ultrasound]] and [[radiography|x-rays]]&lt;ref name=&quot;Grauer_2013&quot;&gt;{{cite web | vauthors = Grauer GF |date= November 2013 |title=Current Thoughts on Pathophysiology and Treatment of Feline Idiopathic Cystitis|url=https://todaysveterinarypractice.com/current-thoughts-on-pathophysiology-treatment-of-feline-idiopathic-cystitis/|access-date=2020-10-16|website=Today's Veterinary Practice|language=en}}&lt;/ref&gt; may be warranted.  However a large bladder and/or the inability to express it is not definitive for blockage.  The cat could be resisting the vet's intervention by &quot;pushing back,&quot; due to anxiety or a desire to avoid a painful urination.

A less frequently seen intermediate case is where the bladder presents as small but is accompanied by severe straining and frequent attempts at urination. This suggests a possible intermittent spasming of the urethra (i.e. an &quot;on-off&quot; [[#Functional blockage|§ 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.

==Pathophysiology==
Feline idiopathic cystitis is above all an [[inflammation|inflammatory process]].

==Non-obstructive episodes of FIC==
Flare-ups of FIC generally begin as non-obstructive incidents. They involve acute inflammation of the lower urinary tract but the cat is still able to urinate. The majority of cases (85%) remain non-obstructive without escalation into blockage and usually resolve themselves within seven days with or without treatment.

=== Causes ===
The direct cause of feline idiopathic cystitis is unknown.  It is a [[diagnosis of exclusion]] which means other possible [[Feline lower urinary tract disease|urinary diseases]] which could cause bladder inflammation (e.g. feline [[urinary tract infection]]s or [https://www.medicinenet.com/script/main/art.asp?articlekey=6649 urolithiasis]) are ruled out.&lt;ref name=&quot;Cook_2013&quot; /&gt;  Research is still being pursued regarding the causes of cystitis in cats, though the following principal risk factors have been identified:&lt;ref name=&quot;:0&quot;&gt;{{cite journal | vauthors = Sævik BK, Trangerud C, Ottesen N, Sørum H, Eggertsdóttir AV | title = Causes of lower urinary tract disease in Norwegian cats | journal = Journal of Feline Medicine and Surgery | volume = 13 | issue = 6 | pages = 410–7 | date = June 2011 | pmid = 21440473 | doi = 10.1016/j.jfms.2010.12.012 | s2cid = 5186889 | pmc = 10832705 }}&lt;/ref&gt;

* Cats predisposed to anxiety or who have a low tolerance to stressors are particularly vulnerable since stress is now considered to be a key factor in triggering acute episodes&lt;ref&gt;{{cite journal | vauthors = Cameron ME, Casey RA, Bradshaw JW, Waran NK, Gunn-Moore DA | title = A study of environmental and behavioural factors that may be associated with feline idiopathic cystitis | journal = The Journal of Small Animal Practice | volume = 45 | issue = 3 | pages = 144–7 | date = March 2004 | pmid = 15049572 | doi = 10.1111/j.1748-5827.2004.tb00216.x }}&lt;/ref&gt;  
* Cats who are [[neutered]] or [[spayed]] too early
* Cats who are younger/middle-aged (i.e. those less than 10 years old)
*Indoor cats and/or cats who are unable express natural feline behaviour (e.g. hunting)&lt;ref name=&quot;:6&quot; /&gt;
* Cats fed a dry food diet who may be inadequately hydrated&lt;ref name=&quot;:6&quot;&gt;{{cite web |title=Feline interstitial cystitis: It's not about the bladder |url=http://veterinarynews.dvm360.com/feline-interstitial-cystitis-it-s-not-about-bladder |archive-url=https://web.archive.org/web/20180303064914/http://veterinarynews.dvm360.com/feline-interstitial-cystitis-it-s-not-about-bladder |archive-date=3 March 2018 |access-date=11 June 2019 |website=DVM 360 |vauthors=Wooten S}}&lt;/ref&gt;&lt;ref name=&quot;:8&quot;&gt;{{Cite news|last=Stevenson|first=Abigail|date=13 October 2011|title=Scientists discover dietary moisture window that boosts urinary tract health in cats|work=WALTHAM Centre for Pet Nutrition|url=https://catinfo.org/docs/WalthamDietaryWater.pdf|access-date=12 October 2020}}&lt;/ref&gt; 
* Increased body weight&lt;ref&gt;{{cite journal | vauthors = Lund HS, Krontveit RI, Halvorsen I, Eggertsdóttir AV | title = Evaluation of urinalyses from untreated adult cats with lower urinary tract disease and healthy control cats: predictive abilities and clinical relevance | journal = Journal of Feline Medicine and Surgery | volume = 15 | issue = 12 | pages = 1086–97 | date = December 2013 | pmid = 23783431 | doi = 10.1177/1098612X13492739 | s2cid = 206691916 | doi-access = free | pmc = 10816473 }}&lt;/ref&gt;

===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|§ mechanical blockage]].  Dry food must therefore be avoided.&lt;ref&gt;{{Cite web|title=Feeding Your Cat: Know the Basics of Feline Nutrition – Common Sense. Healthy Cats.|url=https://catinfo.org/#Cats%20Need%20to%20Eat%20Water-Rich%20Food|access-date=2020-10-11|website=catinfo.org}}&lt;/ref&gt;  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 [[kidney|renal]] or [[stomach|gastric]] [[contraindication]]s).&lt;ref name=&quot;:5&quot;&gt;{{Cite journal| vauthors = Bovens C |date=2012|title=Feline Idiopathic Cystitis|journal=Feline Update at Langford Feline Centre (University of Bristol)}}&lt;/ref&gt;  The condition is 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]] and/or [[dantrolene]] may also be prescribed to control painful urethral spasms and prevent the risk of a [[#Functional blockage|§ functional blockage]].&lt;ref name=&quot;:5&quot; /&gt;  Some research has suggested that prazosin is contraindicated as it leads to recurrent blocking.&lt;ref&gt;{{Cite journal |last1=Conway |first1=David S. |last2=Rozanski |first2=Elizabeth A. |last3=Wayne |first3=Annie S. |date=2022-05-21 |title=Prazosin administration increases the rate of recurrent urethral obstruction in cats: 388 cases |journal=Journal of the American Veterinary Medical Association |volume=260 |issue=S2 |pages=S7–S11 |doi=10.2460/javma.21.10.0469 |issn=1943-569X |pmid=35290210|doi-access=free }}&lt;/ref&gt;  However this remains strongly contested on the basis of widespread anecdotal evidence showing its effectiveness if administered for at least 10–14 days. If prazosin is not prescribed, some form of anti-spasm medication must be given.  In most cases this will be dantrolene. Diazepam is contraindicated as it is associated with harmful side-effects.

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|§ environmental modification]] below). In addition, calming supplements such as [[tryptophan]] or alpha-casozepine can also be added to food to improve mood and relaxation.&lt;ref name=&quot;:5&quot; /&gt;&lt;ref&gt;{{Cite web|title=The role of L-tryptophan/alpha-casozepine|url=https://veterinary-practice.com/article/the-role-of-l-tryptophan-alpha-casozepine|access-date=2020-10-11|website=veterinary-practice.com|language=en}}&lt;/ref&gt;

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 [[antioxidant]]s and [[essential fatty acid]]s such as high quality fish oil have also been shown to reduce the severity of the episode.&lt;ref name=&quot;:2&quot;&gt;{{cite journal | vauthors = Kruger JM, Osborne CA, Lulich JP | title = Changing paradigms of feline idiopathic cystitis | journal = The Veterinary Clinics of North America. Small Animal Practice | volume = 39 | issue = 1 | pages = 15–40 | date = January 2009 | pmid = 19038648 | doi = 10.1016/j.cvsm.2008.09.008 }}&lt;/ref&gt;  The [[veterinarian]] may also use a urine sample from the cat to carry out [[urinalysis]] to test for the [[#The role of crystals in obstructive FIC|§ presence of crystals]] which could aggravate the condition (see below).&lt;ref&gt;Pawprints and Purr Incorporated. &quot;Feline Cystitis&quot;. [http://www.sniksnak.com/cathealth/cystitis.html Feline Cystitis]&lt;/ref&gt;

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 seven days should be suspect for obstruction and investigated further.

== Obstructive episodes of FIC (&quot;the blocked cat&quot;) ==

=== Causes ===
Obstructive episodes occur in the rarer instances (approximately 15% of FIC cases) when the initial, [[#Non-obstructive episodes of FIC|§ non-obstructive attack]] (see above) is not self-limiting and escalates into partial or full block of the urethra.  In this case voiding of urine is impeded or altogether impossible.  Obstruction occurs almost exclusively in male cats due to their long, narrow urethra.  There are two reasons why a cat may obstruct (&quot;block&quot;):

==== Functional blockage ====
The block can be '''functional'''.  This occurs when a severe muscle spasm of the urethra occurs to close it shut (like cramping).  Unless the cat is unable to relax itself again to regain normal function, it cannot urinate. It is intensely painful and is triggered by the underlying inflammation, itself suspected to be caused by the stress of the condition.  Effectively the cat involuntarily &quot;blocks himself&quot;.&lt;ref&gt;{{Cite web|title=Urethral obstruction in cats {{!}} International Cat Care|url=https://icatcare.org/advice/urethral-obstruction-in-cats/#:~:text=A%20cat%20with%20urethral%20obstruction,there%20may%20be%20some%20vomiting|access-date=2020-10-11|website=icatcare.org}}&lt;/ref&gt;

==== Mechanical blockage ====
A '''mechanical''' block occurs when actual physical particles obstruct the urethra.  In 80% of such cases, a '''urethral plug''' composed of material generated from the underlying bladder inflammation (e.g. blood cells, mucus), called matrix, combines with [[struvite]] crystals in the bladder to form a hardened obstruction.  In a small number of cases, the plug will be composed of matrix alone if no crystals are present.

==== Interaction between functional and mechanical blockage in FIC ====
Both functional and mechanical blocks can negatively interact to fully obstruct the cat rapidly.  The underlying inflammation can narrow the urethral opening as well as provoking spasming to cause the walls of the urethra to close shut around a urethral plug forming in it.  For this reason an anti-spasmodic drug such as [[prazosin]] or dantrolene is often advised as it will prevent spasming of the urethra and allow any incipient plug to pass during urinating before it is fully formed and causes obstruction.

==== The role of crystals in obstructive FIC ====
[[Crystalluria]] is the presence of microscopic crystals in feline urine. These are most often [[struvite]] precipitates but other minerals such as [[calcium oxalate]] crystals are also found, albeit less frequently. Urinary crystals are not necessarily an abnormal finding and can be seen both in cats who are healthy and those who are suffering from a urinary tract illness.  However, they can be a risk factor for cats suffering from urinary disease.  Whilst crystals (as opposed to [[bladder stone (animal)|urolith]]s) do not '''alone''' cause a urethral obstruction,&lt;ref&gt;{{Cite web|title=Feline Lower Urinary Tract Disease (FLUTD) {{!}} International Cat Care|url=https://icatcare.org/advice/feline-lower-urinary-tract-disease-flutd/|access-date=2020-10-11|website=icatcare.org}}&lt;/ref&gt; they aggravate the risk of it since they are usually one of the components of a urethral plug which is responsible for [[#Mechanical blockage|§ mechanical blockage]] in obstructive episodes.  The normal pH of feline urine is around 6.5.  However struvite crystals tend to form in concentrated, alkaline urine when the pH is greater than 6.5.  Therefore, stress (which can cause alkalinity&lt;ref&gt;{{cite journal |pmid=8926188|year=1996|last1=Buffington|first1=C. A.|last2=Chew|first2=D. J.|title=Intermittent alkaline urine in a cat fed an acidifying diet|journal=Journal of the American Veterinary Medical Association|volume=209|issue=1|pages=103–104}}&lt;/ref&gt;) or [[supersaturated]] urine (caused by lack of hydration or by stagnant urine collecting in the bladder due to urinary retention) both encourage crystal formation.

Struvite crystalluria can be managed by regulating the urine pH so it stays around 6.5.  A [[urinalysis]] is necessary to determine if the pH is excessively alkaline and a high quality wet meat diet with added acidifiers can be fed to lower the pH (prescription diets achieve a similar effect).  However continuous monitoring of the urine should be undertaken as excessive urine acidity can lead to calcium oxalate formation which cannot be managed via diet but can also lead to obstruction if unchecked.  Regular urinalysis will indicate the nature and extent of crystal formation, together with urine pH, to determine if there are any areas of possible concern which need to be addressed.

=== 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]], draining the backed-up urine and flush the bladder of any sediment (this may include crystals).  This is an invasive, delicate procedure which will require either heavy [[sedation]] or [[general anaesthetic]].  The cat should then be hospitalised with the catheter in place and hydration administered intravenously to encourage healthy urination and good kidney function, ideally for three days.  While the catheter is in place, [[intravesical]] instillation (which is also used to treat human [[interstitial cystitis]]&lt;ref&gt;{{Cite web|last=Publishing|first=Harvard Health|title=Diagnosing and treating interstitial cystitis|url=https://www.health.harvard.edu/diseases-and-conditions/diagnosing-and-treating-interstitial-cystitis|access-date=2020-10-15|website=Harvard Health|date=20 July 2011 }}&lt;/ref&gt;&lt;ref&gt;{{Cite web|title=Bladder Instillation of Cystistat (sodium hyaluronate) – East Sussex Healthcare NHS Trust|url=https://www.esht.nhs.uk/leaflet/bladder-instillation-of-cystistat-sodium-hyaluronate/|access-date=2020-10-15|language=en-GB}}&lt;/ref&gt;&lt;ref&gt;{{Cite web|title=Cystistat® for your interstitial cystitis|url=https://www.guysandstthomas.nhs.uk/resources/patient-information/urology/bladder/cystistat.pdf|access-date=15 October 2020|website=Guy's and St Thomas' NHS Trust}}&lt;/ref&gt;&lt;ref&gt;{{Cite web|title=Bladder Instillations|url=https://www.ichelp.org/diagnosis-treatment/treatments/bladder-instillations/|access-date=2020-10-15|website=Interstitial Cystitis Association|language=en-US}}&lt;/ref&gt;) may also be administered to repair the compromised bladder lining.&lt;ref&gt;{{cite journal | vauthors = Bradley AM, Lappin MR | title = Intravesical glycosaminoglycans for obstructive feline idiopathic cystitis: a pilot study | journal = Journal of Feline Medicine and Surgery | volume = 16 | issue = 6 | pages = 504–6 | date = June 2014 | pmid = 24196569 | doi = 10.1177/1098612X13510918 | s2cid = 12966706 | pmc = 11112186 }}&lt;/ref&gt;&lt;ref&gt;{{Cite web|title=A-Cyst for Animal Use|url=https://www.drugs.com/vet/a-cyst.html|access-date=2020-10-15|website=Drugs.com|language=en}}&lt;/ref&gt; 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).  Medication should be given for long enough to ensure symptoms properly subside at which point it should be slowly tapered off.  This can usually take around 10 – 14 days but could take longer.  Stopping medication too early can result in re-blocking.

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&lt;ref&gt;{{Cite web|title=Feeding your Cat or Kitten {{!}} International Cat Care|url=https://icatcare.org/advice/feeding-your-cat-or-kitten/|access-date=2020-11-22|website=icatcare.org}}&lt;/ref&gt;), 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.  This could trigger [[recrudescence]] i.e. a further acute attack, as well as encouraging calcium oxalate crystal formation which forms in highly acidic urine. 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 good hydration from any wet food the cat finds palatable.  Dry food of any sort (including prescription dry food) should 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.&lt;ref&gt;{{cite journal | vauthors = Litster A, Thompson M, Moss S, Trott D | title = Feline bacterial urinary tract infections: An update on an evolving clinical problem | journal = Veterinary Journal | volume = 187 | issue = 1 | pages = 18–22 | date = January 2011 | pmid = 20044282 | doi = 10.1016/j.tvjl.2009.12.006 }}&lt;/ref&gt;  The symptoms of bacterial infection in the lower urinary tract are very similar to those for non-obstructive FIC (i.e. straining, blood in urine etc.) and a [[Clinical urine tests|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.  Probiotics should be considered after a course of antibiotics to avoid any digestive distress and to allow beneficial gut flora to recolonise which is essential to feline immunity.

== Ongoing management of FIC ==
Since feline idiopathic cystitis is commonly known to reoccur, ongoing precautions need to be taken to avoid relapse.

=== Importance of hydration ===

As domestic cats are descended from their desert-inhabiting ancestors, they instinctively seek moisture from their prey.{{Citation needed|date=January 2023}}  High quality wet food is the most natural way therefore to hydrate a cat as drinking water from a bowl is arguably species-inappropriate since anatomical limitations in the cat's tongue restrict the amount of water they can ingest this way.&lt;ref&gt;{{Cite web|last=Staff|first=((Today's Veterinary Business))|date=2020-01-23|title=Purina sees Hydra Care as dehydration solution|url=https://todaysveterinarybusiness.com/purina-sees-hydra-care-as-dehydration-solution/|access-date=2020-11-14|website=Today's Veterinary Business|language=en}}&lt;/ref&gt;  Drinking still water from a bowl (particularly tap as opposed to rain water) is often a last resort for many cats and some may avoid it altogether.  A quality wet food diet will therefore be most effective in ensuring sufficient moisture intake and will always be more effective than dry food in hydrating a cat, even when any additional moisture intake from drinking water is taken into account.&lt;ref name=&quot;:8&quot; /&gt;

Supplementing wet food with [[antioxidant]]s and [[essential fatty acid]]s such as high quality fish oil have also been shown to reduce the severity and recurrence of FIC episodes.&lt;ref name=&quot;:2&quot; /&gt;

=== Environmental modification ===
Together with hydration, improvements to the cat's environment have been shown to prevent relapses.&lt;ref&gt;{{cite journal | vauthors = Buffington CA, Westropp JL, Chew DJ, Bolus RR | title = Clinical evaluation of multimodal environmental modification (MEMO) in the management of cats with idiopathic cystitis | journal = Journal of Feline Medicine and Surgery | volume = 8 | issue = 4 | pages = 261–8 | date = August 2006 | pmid = 16616567 | doi = 10.1016/j.jfms.2006.02.002 | s2cid = 33415205 | pmc = 10822542 }}&lt;/ref&gt;  Reducing stress and encouraging natural feline behaviour (particularly for indoor cats) is essential.  Suggested methods include:

* No sudden disruption to routine or changes in a cat's environment.&lt;ref&gt;{{cite journal | vauthors = Stella J, Croney C, Buffington T | title = Effects of stressors on the behavior and physiology of domestic cats | journal = Applied Animal Behaviour Science | volume = 143 | issue = 2–4 | pages = 157–163 | date = January 2013 | pmid = 25210211 | doi = 10.1016/j.applanim.2012.10.014 | series = Special Issue: Laboratory Animal Behaviour and Welfare | pmc = 4157662 }}&lt;/ref&gt;
* [[Olfaction|Olfactory]] enrichment with indoor cat-safe plants (e.g. cat grass, catnip, silver vine or cat thyme)&lt;ref&gt;{{cite journal | vauthors = Bol S, Caspers J, Buckingham L, Anderson-Shelton GD, Ridgway C, Buffington CA, Schulz S, Bunnik EM | display-authors = 6 | title = Responsiveness of cats (Felidae) to silver vine (Actinidia polygama), Tatarian honeysuckle (Lonicera tatarica), valerian (Valeriana officinalis) and catnip (Nepeta cataria) | journal = BMC Veterinary Research | volume = 13 | issue = 1 | article-number = 70 | date = March 2017 | pmid = 28302120 | pmc = 5356310 | doi = 10.1186/s12917-017-0987-6 | doi-access = free }}&lt;/ref&gt; can again replicate a pleasing, natural environment indoors.	
*Outdoor visits (supervised in the case of indoor cats) will encourage sensory stimulation and defeat boredom which could lead to stress.
*Window sill perches (particularly if they look out onto a natural landscape with wildlife and birds) provide important visual stimulation, particularly for cats who have no outdoor access.&lt;ref name=&quot;:3&quot;&gt;{{Cite journal|last=Buffington|first=C. A. Tony|date=2002-04-01|title=External and internal influences on disease risk in cats|journal=Journal of the American Veterinary Medical Association|volume=220|issue=7|pages=994–1002|doi=10.2460/javma.2002.220.994|pmid=12420776|issn=0003-1488|doi-access=free}}&lt;/ref&gt;  Ideally the perches should be affixed to windows which provide good visibility of the surrounding outdoor space (windows on lower floors of a building work better therefore than those on floors which are too high up).  Perches should be affixed at a variety of locations to offer diverse vantage points.	
*Maintaining close contact with owners and avoiding extended periods of isolation to prevent [[Separation anxiety disorder|separation anxiety]].  This is particularly important for rescued strays or abandoned cats who have since been re-homed in an environment they perceive as safe.
* Play with owners in short bursts de-stresses a cat and stimulates positive neural activity.   	
* Regular rotation and replacement of cat toys.&lt;ref name=&quot;:1&quot;&gt;{{Cite web|title=Feline Idiopathic Cystitis|url=https://www.thecatclinic.ca/uploads/new-medical-support-item/Feline%20Idiopathic%20Cystitis%20Client%20Handout.pdf|website=www.thecatclinic.ca}}&lt;/ref&gt;
* Safe, enclosed, quiet sleeping areas such as igloo beds.&lt;ref&gt;{{Cite web|date=2015-02-06|title=Why do cats love sleeping in cardboard boxes? Scientists may have the answer|url=https://www.independent.co.uk/news/science/scientists-crack-great-mystery-why-do-cats-love-sleeping-cardboard-boxes-10029762.html|access-date=2020-11-22|website=The Independent|language=en}}&lt;/ref&gt;
* Avoidance of sudden or loud noises which could adversely trigger the [[startle response]] (classical music or special &quot;Cat Music&quot; in the background can be used to mitigate this).
* Litter tray hygiene and availability.

=== Surgical intervention for refractory cases ===
For recurrent cases of FIC in male cats where blockage is a risk, and dietary and environmental modifications have not prevented relapse, a last line of treatment to prevent future obstruction is surgery to widen the male urethra.  This is called Perineal Urethrostomy (PU)&lt;ref&gt;{{Cite web|title=Perineal Urethrostomy Surgery in Cats|url=http://vcahospitals.com/know-your-pet/perineal-urethrostomy-surgery-in-cats|access-date=2020-12-02|website=vca_corporate|language=en}}&lt;/ref&gt; but brings with it other risks and should therefore only be considered once all other options have been exhausted.

== References ==
{{reflist}}

[[Category:Cat diseases]]