Theory. The glycosaminoglycan layer is deficient, allowing for toxic insult to the urothelium.
Evidence. Pentosan polysulfate sodium and glucosamine are two agents that have been studied in cats with iFLUTD.
- Pentosan polysulfate sodium (2 to 16 mg/kg b.i.d. or 8 mg/kg b.i.d. given orally42 ): This particular glycosaminoglycan has been shown to be helpful in 28% to 68% of people with idiopathic cystitis and has
been used anecdotally in some cats with success.43 Elmiron (Ortho-McNeil-Janssen Pharmaceuticals), the product approved in the United States for use in people, needs to be
formulated to smaller capsule sizes. The drug is well-tolerated in cats, and though it can cause bleeding in any species because
of its anticoagulant properties, this side effect has not specifically been reported in cats.42
- Glucosamine (Cosequin for Cats—Nutramax Laboratories) (1 capsule [125 mg glucosamine, 100 mg chondroitin sulfate] daily for
cats < 10 lb; 1 capsule b.i.d. for cats > 10 lb given orally44 ): One study showed no significant difference between the severity or duration of iFLUTD in client-owned cats receiving oral
glucosamine vs. a placebo. Two cats in the placebo group, however, were euthanized because of severe, recurrent disease.43 Side effects can include minor gastrointestinal signs such as flatulence and soft stool.44
Bottom line. Oral glucosamine supplementation has few side effects, and long-term therapy may be useful in conjunction with other therapies
in cats with chronic, recurrent iFLUTD.
Increase water intake
Theory. A decreased urine concentration decreases the concentration of components that may be toxic to the urothelium.
Evidence. Dilute urine may reduce the concentration of noxious urinary components that can be bladder wall irritants.12,43,45 Several studies evaluating dietary or other supplements in the treatment of iFLUTD in cats concluded that the main correlation
between improvement in clinical signs or reduced recurrences was the feeding of a canned diet.43,46 Offer cats canned food choices, and then remove the dry food gradually. This measure establishes a constancy of the water
content and diet composition, which appears to be important.5 Drinking water preferences, such as bowl type, water depth, and running vs. still water, should be determined to ensure
adequate water intake.
Bottom line. Transition to a consistent canned diet, and encourage water consumption by determining a cat's drinking preferences.
Theory. Stress has been associated with iFLUTD recurrence and may play a role in the disease's pathophysiology, both systemically
and locally in the bladder.
Evidence. Stress reduction measures that have been investigated in cats with iFLUTD include feline facial pheromones and environmental
- Pheromones, chemical substances that are found, for example, in sebaceous secretions in the cheeks, likely affect the limbic
and hypothalamic regions.47,48 The F3 fraction of the five facial pheromone fractions isolated in cats is deposited on objects by facial rubbing and serves
to mark territory and decrease aggressive behavior. Feliway (Ceva Santé Animale), a synthetic analogue of the F3 fraction
of feline facial pheromone, has been used for behavior modification, including urine spraying.47 In a clinical study, Feliway resulted in a trend (though no statistically significant difference was noted) toward fewer
days of clinical signs of cystitis and a reduced number of episodes of iFLUTD.49
- Multimodal environmental modification: Implementation of a stress and environmental management protocol that uses client education,
environmental enrichment, and husbandry changes appears to be an important aspect of therapy. Multimodal environmental modification
(MEMO) involves making adjustments to litter boxes (number, location, size and shape, litter type), scratching posts (number,
location, texture), sleeping and eating areas, perches, and toys.5,48,50 Client education includes providing information about cat behavior in relation to people and other cats, explaining the
iFLUTD syndrome, empathizing with the owner's frustrations and concerns, and encouraging the owner not to blame the cat for
the disorder.50 Tailor MEMO to the specific surroundings and interactions in a cat's environment. A recent study in which owners used MEMO
demonstrated a significant reduction in their cats' LUTS, fear, nervousness, and respiratory signs (coughing, sneezing, wheezing)
and a trend toward reduced aggression. In 70% to 75% of the 46 cats in this study, there was no evidence of LUTS in the 10-month
Bottom line. Incorporate MEMO in the management of iFLUTD, and add synthetic feline facial pheromones as a component of stress management.
For more information, see The Indoor Cat Initiative through The Ohio State University College of Veterinary Medicine Web site:
Based on the current literature, the most important therapies appear to be stress management using feline facial pheromones
and MEMO and increasing water intake through the use of canned diets. No specific canned diet is recommended but rather is
determined by the cat's preference. For chronic recurrent episodes, adjunctive therapy with long-term amitriptyline and glycosaminoglycan
supplementation may be beneficial.
A frustrating and potentially life-threatening disease in cats, iFLUTD results in pain, pollakiuria, hematuria, periuria,
stranguria, and, in some cases, urethral obstruction. It is a diagnosis of exclusion made only after conducting a thorough
work-up. The results of studies evaluating possible causes have been conflicting and reveal that the syndrome is likely multifactorial.
Further studies are needed to establish the contributions of each possible mechanism.
The efficacy of specific treatments is difficult to assess because of iFLUTD's self-limiting nature. In general, drug therapies
that attempt to target potential causes have had disappointing results. The management tactics that seem most promising include
reducing stress through MEMO and feline facial pheromones and adjusting the diet to include canned food and increased water
intake. Amitriptyline and glycosaminoglycan supplementation may provide additional benefits for chronic, recurrent episodes,
but further studies are needed to establish efficacy.
Kristy Dowers, DVM, MS, DACVIM
Department of Clinical Sciences
College of Veterinary Medicine and Biomedical Sciences
Colorado State University
Fort Collins, CO 80523