Characterized by clinical signs of lower urinary tract inflammation for which an underlying cause is not identified
Considered the most common cause of feline lower urinary tract disease (FLUTD); occurs in approximately 2/3 of cats with signs of lower urinary tract disease who are < 10 years of age
Etiology is multifactorial and involves pathways outside of the urinary tract; chronic stimulation of the body’s stress response, release of stress catecholamines and chemical mediators activate the nervous and endocrine systems, contributing to neurogenic bladder inflammation
May present with or without urethral obstruction; obstruction is most common in young, male, overweight cats
In cats with non-obstructive form, clinical signs may resolve within 2 to 3 days with no therapy; however, rate of recurrence is high
Diagnosis is based on history, signalment, environmental risk factors, and exclusion of other common causes of lower urinary tract disease (e.g., urocystoliths)
Treatment is aimed at reducing the severity and frequency of clinical signs; response to therapy may be inconsistent
Multimodal environmental modification (MEMO)
Client education and communication are critical to successful management
Prognosis is variable; frequent recurrence increases the risk of euthanasia or rehoming/surrender
Causes and Risk Factors
Causes
Multifactorial; underlying cause is often not identified
Environmental or physiologic stress (particularly chronic stress) activates the body’s stress response, releasing stress catecholamines and chemical mediators that activate the nervous and endocrine systems, contributing to neurogenic bladder inflammation
Decreased excretion of urinary glycosaminoglycans, increased bladder permeability, increased serum catecholamine levels, and increased excitability of bladder afferent neurons have been reported
Role of viruses as a cause of lower urinary tract disease remains unclear
Environmental and behavioral stressors thought to play a role
Risk Factors
Obesity
Nervous disposition
Genetics
Decreased activity
Environmental stressors; may include but are not limited to:
Indoor housing
Litter box placement or substrate (non-clumping litter may increase risk)
Diagnosis is based on history, signalment, environmental risk factors, and exclusion of other common causes of lower urinary tract disease (e.g., urocystoliths)
Clinical signs vary in severity; may wax and wane
Signs may be exacerbated by stress
Many cats have resolution of clinical signs without therapy; therefore, diagnostics may not be necessary in a young cat with a first occurrence of clinical signs
Bacterial urinary tract infection is rare in young, otherwise healthy cats; cats with perineal urethrostomy, repeated catheterizations, or underlying metabolic/endocrine disease may be at greater risk of infection
Signs and History
Hematuria
Dysuria
Pollakiuria
Stranguria
Periuria
Inappropriate urination; owner may misinterpret as urine marking/spraying
Overgrooming (abdomen, perineum, rear legs ) due to pain
Hiding
Behavioral changes, including aggression
Urethral obstruction possible
A detailed environmental history and timeline of onset of clinical signs should be considered as part of the initial assessment
Physical Exam
May be normal
Abdominal pain possible; prepubic hair loss may indicate presence of bladder pain
Findings will depend on the presence of an underlying disease process
Cats with hyperthyroidism may demonstrate polyuria; may be mistaken for lower urinary tract disease
Imaging
Abdominal radiography
Will aid in identification of radioopaque uroliths
Abdominal ultrasonography
Should be considered in older cats (>10 years of age) that have signs of lower urinary tract disease
Useful in identifying bladder abnormalities such as polyps, stones, blood clots, debris, or neoplasia
Contrast cystogram/cystourethrogram
May be considered in cats with recurrent episodes of lower urinary tract signs or those who are unresponsive to therapy
May identify mass lesions, radiolucent calculi, thickening of the bladder wall, or urethral stricture (specifically in males)
Cystoscopy
Can be performed in female cats and males that have undergone perineal urethrostomy
Referral to a veterinary specialist should be considered
Allows direct visualization of the bladder and urethra, with collection of biopsy samples if needed
Treatment
General Points
Many cats may have resolution of clinical signs within 2 to 7 days without therapy; however, recurrence of clinical signs is common, often within 12 months
Multimodal environmental modification (MEMO) involves adjusting resources (e.g., food and water stations, litterboxes, toys, etc.) to reduce stress and improve the cat’s sense of control
Therapy should be initiated for patients with recurrent signs of lower urinary tract disease
There is no consensus on the optimal treatment for cats with idiopathic cystitis; transitioning to a moist diet, effective environmental enrichment (see Other Therapies), and use of a multipurpose therapeutic urinary diet have the highest levels of evidence
Treatment is aimed at reducing the severity and frequency of clinical signs
Response to therapy may be inconsistent
For cats receiving daily oral medication, the stress associated with being medicated can exacerbate the condition and complicate assessment of therapeutic response
For many medications, high-level studies demonstrating efficacy are lacking
May be considered for cats that do not respond to nutritional or environmental therapy; can take weeks to note improvement so not indicated for acute management
If ineffective, drugs should be weaned over 1 to 2 weeks and not abruptly discontinued
Options include:
Gabapentin 5 to 10 mg/kg PO every 12 hours
Amitriptyline 2.5 to 7.5 mg per cat, PO every 24 hours
Efficacy is variable
Treatment should be initiated at the low end of the dose range
Side effects include lethargy, weight gain, and urine retention
Clomipramine 0.25 to 0.5 mg/kg PO every 24 hours; up to 1 mg/kg PO every 24 hours
Use in combination with behavior modification therapy
May cause sedation
Fluoxetine 0.5 to 1.3 mg/kg PO every 24 hours
Can help reduce urine spraying
Demonstration of therapeutic response may take up to 8 weeks
May cause a decrease in appetite; urine retention has been reported
Alprazolam 0.125 to 0.25 mg per cat, PO every 8 to 12 hours
Although idiosyncratic hepatic injury has not been reported with alprazolam, use oral benzodiazepines with caution in cats
Lorazepam 0.125 to 0.25 mg per cat, PO every 12 to 24 hours
Alternate dosage: 0.05 mg/kg PO every 12 to 24 hours
Start at the low end of the dose range
May cause sedation or paradoxical excitement
Although idiosyncratic hepatic injury has not been reported with lorazepam, use oral benzodiazepines with caution in cats
Goal is to increase the cat’s sense of control, and reduce perceived threats
Has been found to decrease the clinical signs of idiopathic cystitis and lower the rate of recurrence
Removal of environmental stressors is recommended whenever possible
Environmental enrichment recommendations include:
Providing safe havens (e.g., climbing posts/perches, secure hiding spots, window perches) spread throughout the house
Provide different types of scratching surfaces (e.g., horizontal and vertical, different substrates and textures, different heights and locations)
Rotate toys regularly, to discourage boredom
In multi-cat households, provide separate feeding areas, multiple water locations, and multiple litter boxes (at least one box per cat and one more litterbox than the number of cats); litter box size, locations, and substrates may need to be changed as well
Litterboxes should be in separate rooms, and not side-by-side
Scoop boxes daily (at least)
Unscented, sandy-type litter is generally preferred, but additional types and textures can be offered to discern the cat’s preference
Most cats prefer an open litterbox, but different types can be offered, to determine the cat’s preferences
Size: the litterbox should be at least 1.5 times the length of the cat, minus the tail
Owners should be mindful of potential obstacles (e.g., stairs) and deterrents (e.g., appliances, air vents or ducts) that can contribute to stress and/or hinder accessibility
Older cats, or cats with mobility limitations may benefit from a litterbox with shallower edges, or a cut-out section for easier access
Increased activity (e.g., leash-walking, interactive play time, positive-reinforcement training)
Provide food puzzles and/or toys that encourage expression of predatory behavior
Provide positive human-cat interaction (e.g., grooming, petting, playing)
Avoid using heavily perfumed or noxious smelling substances for cleaning, or in the home in general
Whenever possible, routines should be stable; e.g., feeding should happen at the same times each day
Nutritional therapy
Can be a component of a multimodal approach, but is unlikely to resolve the condition as a monotherapy
Acidifying diets are not recommended for cats with idiopathic cystitis
Feeding a moist diet (>70%) has been associated with a decreased risk of recurrence of clinical signs
In the absence of concurrent medical conditions, a multipurpose therapeutic urinary diet should be considered
For patients with concurrent urolithiasis, diet composition must be determined on a case by case basis
A change in the diet should not be attempted until the cat is well; transition to a new diet over 3 to 5 days
Weight management should be a therapeutic goal, as obesity contributes to disease risk and likelihood of recurrence
Feline synthetic facial pheromone therapy
Use of pheromones has been reported to reduce anxiety and may be of benefit to some cats with this disease; if used, should be combined with other therapies
One spray in affected area once daily
A room diffuser may be considered as well
Follow-up
General Points
Client education and communication will be critical for successful management
Owners should be instructed about how to interpret feline behaviors and recognize signs of stress
Diagnostic Follow-up
Will depend on any underlying diseases
Therapeutic Follow-up
Follow-up phone consultation should be conducted within 2 weeks of initial evaluation to assess response to therapy
Cats receiving fluoxetine may take up to 8 weeks to demonstrate a therapeutic response
Prognosis
Variable; client communication is critical for successful environmental management
In a Level 3 survey, 70% of affected cats recovered and experienced few recurrences or none at all
Increased frequency of recurrence increases the likelihood of euthanasia or rehoming
Evidence
Guidelines and Consensus Statements
Taylor S, Boysen S, Buffington T, et al. 2025 iCatCare consensus guidelines on the diagnosis and management of lower urinary tract diseases in cats. J Feline Med Surg. 2025 Feb;27(2):1098612X241309176. Level BArticle
Carney HC, Sadek TP, Curtis TM, et al. AAFP and ISFM Guidelines for Diagnosing and Solving House-Soiling Behavior in Cats. J Feline Med Surg. 2014 Jun 25;16(7):579-98. Level B (IND) Article
Ellis SL, Rodan I, Carney HC, et al. AAFP and ISFM feline environmental needs guidelines. J Feline Med Surg. 2013 Mar;15(3):219-30. Level BArticle
Systematic Reviews/Meta-analyses
Frank D, Beauchamp G, Palestrini C. Systematic review of the use of pheromones for treatment of undesirable behavior in cats and dogs. J Am Vet Med Assoc. 2010 Jun 15;236(12):1308-16. Level BAbstract
Randomized, Controlled Trials (RCTs)
Panchaphanpong J, Asawakarn T, Pusoonthornthum R. Effects of oral administration of N-acetyl-d-glucosamine on plasma and urine concentrations of glycosaminoglycans in cats with idiopathic cystitis. Am J Vet Res. 2011 Jun;72(6):843-50. Level 2Abstract
Kruger JM, Conway TS, Kaneene JB, et al. Randomized controlled trial of the efficacy of short-term amitriptyline administration for treatment of acute, nonobstructive, idiopathic lower urinary tract disease in cats. J Am Vet Med Assoc. 2003 Mar 15;222(6):749-58. Level 2Abstract
Other Studies or Reviews
Defauw PA, Van de Maele I, Duchateau L, et al. Risk factors and clinical presentation of cats with feline idiopathic cystitis. J Feline Med Surg. 2011 Dec;13(12):967-75. Level 2Abstract
Cameron ME, Casey RA, Bradshaw JW, et al. A study of environmental and behavioural factors that may be associated with feline idiopathic cystitis. J Small Anim Pract. 2004 Mar;45(3):144-7. Level 2Abstract
Jones BR, Sanson RL, Morris RS. Elucidating the risk factors for feline lower urinary tract disease. N Z Vet J. 1997 Jun;45(3):100-8. Level 2Abstract
Buffington T, Delgado MM. Feline idiopathic/interstitial cystitis. In: Cote E, Ettinger SJ, Feldman EC, ed.’s. Ettinger’s Textbook of Veterinary Internal Medicine. 9th ed. Philadelphia: Elsevier; 2024:2171-8. Level 3
Krause LR, Li E, Lilly ML, et al. Survey of veterinarians in the USA to evaluate trends in the treatment approach for non-obstructive feline idiopathic cystitis. J Feline Med Surg. 2024 Aug;26(8):1098612X241260716. Level 3
He C, Fan K, Hao Z, et al. Prevalence, risk factors, pathophysiology, potential biomarkers and management of feline idiopathic cystitis: an update review. Front Vet Sci. 2022 Jun 21;9:900847. Level 3
Papich MG. Papich Handbook of Veterinary Drugs, 5th Edition. St Louis, MO: Elsevier; 2021. Level 3
Eggertsdóttir AV, Blankvandsbråten S, Gretarsson P, Retrospective interview-based long-term follow-up study of cats diagnosed with idiopathic cystitis in 2003-2009. J Feline Med Surg. 2021 Oct;23(10):945-51. Level 3
Amat M, Camps T, Manteca X. Stress in owned cats: behavioural changes and welfare implications. J Feline Med Surg. 2016 Aug;18(8):577-86. Level 3
Lund HS, Sævik BK, Finstad ØW, et al. Risk factors for idiopathic cystitis in Norwegian cats: a matched case-control study. J Feline Med Surg. 2016. Jun;18(6):483-91. Level 3
Forrester SD, Towell TL. Feline idiopathic cystitis. Vet Clin North Am Sm Anim Pract. 2015 Jul;45(4):783-806. Level 3
Shreyer TA, Buffington CAT. Mulitmodal environmental enrichment for domestic cats. . In: Bonagura JD, Twedt D, ed’s. Kirk’s Current Veterinary Therapy XV. Philadelphia: Elsevier Saunders;2014:909-14. Level 3
Buffington CAT. Idiopathic cystitis in domestic cats--beyond the lower urinary tract. J Vet Intern Med. 2011 Jul-Aug;25(4):784-96. Level 3
Elliott DA. Nutritional management of the lower urinary tract conditions. In: Ettinger SJ, Feldman EC, ed.’s. Textbook of Veterinary Internal Medicine. 7th ed. St. Louis: Saunders Elsevier; 2010:696-701. Level 3
Westropp JL, Buffington CAT. Lower urinary tract disorders in cats. In: Ettinger SJ, Feldman EC, ed.’s. Textbook of Veterinary Internal Medicine. 7th ed. St. Louis: Saunders Elsevier; 2010:2069-86. Level 3
Forrester SD, Roudebush P. Evidence-based management of feline lower urinary tract disease. Vet Clin North Am Small Anim Pract. 2007 May;37(3):533-58. Level 3 (IND)
Westropp JL, Kass PH, Buffington CA. Evaluation of the effects of stress in cats with idiopathic cystitis. Am J Vet Res. 2006 Apr;67(4):731-6. Level 3
Buffington CAT. External and internal influences on disease risk in cats. J Am Vet Med Assoc. 2002 Apr 1;220(7):994-1002. Level 3
Buffington CA, Chew DJ, Kendall MS, et al. Clinical evaluation of cats with nonobstructive urinary tract diseases. J Am Vet Med Assoc. 1997 Jan 1;210(1):46-50. Level 3
Additional Reading
Colombino E, Cavana P, Martello E, et al. A new diet supplement formulation containing cranberry extract for the treatment of feline idiopathic cystitis. Nat Prod Res. 2022 Jun;36(11):2884-7.
Naarden B, Corbee RJ. The effect of a therapeutic urinary stress diet on the short-term recurrence of feline idiopathic cystitis. Vet Med Sci. 2020 Feb;6(1):32-8.
Kruger JM, Lulich JP, MacLeay J, et al. Comparison of foods with differing nutritional profiles for long-term management of acute nonobstructive idiopathic cystitis in cats. 2015 Sep 1;247(5):508-17.
Buffington CA, Westropp JL, Chew DJ. From FUS to Pandora syndrome: where are we, how did we get here, and where to now? J Feline Med Surg. 2014 May;16(5):385-94.
Bradley AM, Lappin MR. Intravesical glycosaminoglycans for obstructive feline idiopathic cystitis: a pilot study. J Feline Med Surg. 2013;16(6):504-6.
Frank D, Beauchamp G, Palestrini C. Systematic review of the use of pheromones for treatment of undesirable behavior in cats and dogs. J Am Vet Med Assoc. 2010 Jun 15;236(12):1308-16.