Feline lower urinary tract disease (FLUTD) is not a single disease process but a term used to describe a group of different diseases involving the feline urinary bladder and urethra. International Cat Care has stated that FLUTD typically affects 1 to 3 percent of cats each year. Due to the diverse nature of the underlying causes, it can affect cats of any age, gender and breed. However, risk factors predisposing cats to FLUTD have been identified and include: being middle-aged, neutering, being overweight, having a predominately dry diet, taking little exercise or having restricted outside access and having a nervous disposition (Gunn-Moore and Cameron, 2004).
Feline idiopathic cystitis (FIC) is the most frequent cause, accounting for approximately two-thirds of FLUTD cases (Gerber et al., 2005) and is diagnosed by a process of exclusion, where no specific underlying cause can be identified. FIC is a complex condition and the primary cause is still not yet known. Several studies have identified anomalies at the level of the urinary bladder, sympathetic nervous system and cortical adrenal function (Buffington, 2011). Stress is also believed to have an important role in triggering or exacerbating the condition with a link identified between cats that display fearful, nervous and aggressive behaviour and FIC (Bowen and Heath, 2005; Buffington et al., 2006a). Other important causes of FLUTD are listed in Table 1.
|Bacterial urinary tract infections||One of the most common causes of lower urinary tract disease in many animals, but relatively uncommon in cats. It accounts for around 5 to 15 percent of all cases of FLUTD (Gerber et al., 2005). Tends to be seen in older cats, particularly if they have an underlying disease, such as chronic kidney disease, hyperthyroidism or diabetes mellitus.|
|Urolithiasis||The two most common types of stone reported are magnesium ammonium phosphate (struvite) and calcium oxalate. These two types of stone account for 80 to 90 percent of cases of urolithiasis, but others may also be seen. Urolithiasis generally accounts for around 15 to 23 percent of cases of FLUTD (Gerber et al., 2005)|
|Urethral plugs||Account for about 20 percent of FLUTD cases in cats less than 10 years of age (Caney and Gunn-Moore, 2014). Caused by an accumulation of proteins, cells, crystals (usually struvite) and debris in urine that combine to form a plug that cannot be passed. Urethral plugs are often associated with FIC and most clinicians believe this is a subset of FIC. Urethral obstruction may be caused by the plug itself, but in the case of FIC can also be caused by urethral spasm associated with pain.|
|Bladder neoplasia||Transitional cell carcinoma (TCC), leiomyoma and adenocarcinoma have been reported in the bladders of cats. TCCs are most frequently reported either as an isolated tumour or arising secondary to chronic inflammation. Although uncommon, the possibility needs to be considered – particularly in older cats.|
|Anatomical defects||If the urethra becomes damaged, fibrous tissue may develop during the healing process, which can significantly restrict the diameter of the urethra.|
These disorders can be split into two categories: obstructive and non-obstructive (Caney and Gunn-Moore, 2014). Cats with obstructive disease are unable to pass urine and are often referred to as “blocked” cats. Urethral obstruction is a veterinary emergency and cats with this condition may die within a couple of days if they are left without appropriate treatment.
Cats with non-obstructive disease are able to pass urine and usually present with one or more of a range of clinical signs listed in Table 2.
|Dysuria||Difficult or painful urination|
|Pollakiuria||Increased frequency of urination|
|Haematuria||Blood in the urine|
|Stranguria||Straining to urinate|
|Periuria||Urinating outside the litter box and in unusual or inappropriate places|
|Behavioural changes||Some cats may show only these and can exhibit signs such as loss of litter-training, aggression or irritability|
|Over-grooming||Often related to pain and irritation in the bladder and urethra causing some cats to over-groom and lick around their perineum|
Clinical signs for these disorders are all so similar that it is often difficult to determine the underlying cause. Diagnosis may require a full behavioural and clinical history, physical examination, blood and urinalysis, imaging and potentially biopsy of the urinary tract. Diagnosing the cause of FLUTD is of particular importance in cats that show repeated episodes or where the clinical signs are persistent.
Managing the disease
Treatment of FLUTD will depend on the underlying cause. Successful management depends on a long-term commitment and a joint approach with the cat’s care provider and the veterinary team but will generally require a multimodal strategy. Important objectives in all cases are increasing water intake, reducing stress and dietary management.
Increasing water intake is important to aid urine dilution and increase urination frequency (Eisenberg et al., 2013). Different methods of increasing water intake include: increasing the number of bowls, changing the type of bowl, changing diets, changing the location of bowls and changing the type of water (eg to room temperature tap water, mineral water, rainwater or flavoured broths).
Given the role stress has been proven to play in FLUTD, particularly in cases of FIC, efforts should be focused on identifying and addressing potential causes of stress in the home and owners should be educated on how to keep stress to a minimum (Caney and Gunn-Moore, 2014).
One of the most common causes of stress for cats is being in a multi-cat household. To address this, care needs to be taken to understand the number of social groups within the home and determine whether adequate resources are available for each group. Other common stressors include the addition of new pets or people into the home or neighbourhood and sudden changes in routine. In severe cases, referral to a veterinary behaviourist may be required.
Adjunctive approaches to reducing stress should also be considered. Enrichment of the cat’s environment through the provision of climbing frames with resting areas and playing games that stimulate natural behaviour can be beneficial. However, any alteration to the cat’s environment should not be made suddenly; drastic changes may elicit new episodes of FLUTD (Buffington et al., 2006b).
Further methods of reducing stress include synthetic pheromone preparations, such as facial pheromone and cat appeasing pheromone (Gunn-Moore and Cameron, 2004). Nutraceuticals such as alpha-casozepine, a milk protein hydrolysate thought to have an anxiolytic effect, and tryptophan, an essential amino acid and precursor for serotonin synthesis, are believed to contribute to feelings of well-being (Meyer and Becvarova, 2016).
Dietary management is useful for combating the physical aspects of FLUTD by reducing the likelihood of urolith formation, increasing water turnover through the bladder of affected cats and modulating inflammatory mediators. The type of diet will depend on the urinalysis results and cat’s body condition; there are commercially available options.
FLUTD is an important cause of illness in cats and can be a distressing condition for both the cat and its carer. The best success rates are achieved by making an accurate diagnosis, so the most appropriate treatment can be prescribed. Management must be multimodal, including identifying and controlling underlying medical disorders, using dietary management, identifying and alleviating stressors in the cat’s environment and modifying where appropriate.