Evidence-based management of feline lower urinary tract disease.

Many treatments have been recommended for managing cats with feline urinary tract disease (FLUTD). Veterinarians making therapeutic decisions should consider the quality of evidence supporting a recommendation to use (or not use) a particular treatment for cats with FLUTD. Whenever possible, recommendations should be based on results of randomized and well-controlled scientific studies performed in clinical patients with the spontaneously occurring disease of interest. In the absence of such studies, one is left to make the best recommendation possible with consideration of all information, including the quality of the evidence. At this time, additional studies are needed to evaluate evidence for many currently recommended treatments for cats with FLUTD.     

Recent concepts in feline lower urinary tract disease.

This article presents and discusses recent concepts in feline lower urinary tract disease.     

Nutrition and lower urinary tract disease in cats.

Lower urinary tract disease occurs commonly in cats and is often associated with crystal-related disease. Dietary modification is beneficial in managing some of these diseases, including idiopathic cystitis, urolithiasis, and urethral matrix-crystalline plugs. Altering dietary formulation may result in decreasing urinary concentrations of crystallogenic compounds, increasing urinary concentrations fo crystallogenic inhibitors, and diluting urine composition.     

Elucidating the risk factors of feline lower urinary tract disease

A questionnaire-based case-control study investigating the association of a range of host-related, owner-related and environmental risk factors with feline lower urinary tract disease was conducted in New Zealand over a 2-year period from 1991 to 1993. The study was subsequently extended in two ways, to examine the influence of the use of litter trays and to correlate weather records with the appearance of the disease in one particular region of the country. A range of statistical techniques was employed to analyse the data, including univariate odds ratio and chi-squared calculations, time series analysis, Poisson regression and conditional and unconditional logistic regression. Variables that were positively associated with lower urinary tract disease included low activity levels, the use of a litter tray coupled with restriction indoors, a high number of rainfall days in the month preceding the appearance of clinical signs, stress factors such as moving house within the last 3 months or the presence of more than one cat in the household, and a diet high in dry cat food. There was some indication that high levels of fluid consumption reduced the effect of a diet high in dry cat food. Other variables that appeared to have some protective effects included a routine visit to the veterinarian in the last 12 months and the use of alternative food sources such as rodents and birds.     

Genetic characterization of 2 novel feline caliciviruses isolated from cats with idiopathic lower urinary tract disease

Feline caliciviruses (FCVs) are potential etiologic agents in feline idiopathic lower urinary tract disease (I-LUTD). By means of a modified virus isolation method, we examined urine obtained from 28 male and female cats with nonobstructive I-LUTD, 12 male cats with obstructive I-LUTD, and 18 clinically healthy male and female cats. All cats had been routinely vaccinated for FCV. Two FCVs were isolated; I (FCV-U1) from a female cat with nonobstructive I-LUTD, and another (FCV-U2) from a male cat with obstructive I-LUTD. To determine the genetic relationship of FCV-U1 and FCV-U2 to other FCVs. capsid protein gene RNA was reverse transcribed into cDNA, amplified, and sequenced. Multiple amino acid sequence alignments and phylogenetic trees were constructed for the entire capsid protein, hypervariable region E, and the more conserved (nonhypervariable) regions A, B, D, and F. When compared to 23 other FCV isolates with known biotypes, the overall amino acid sequence identity of the capsid protein of FCV-U1 and FCV-U2 ranged from 83 to 96%; identity of hypervariable regions C and E ranged from 58 to 85%. Phylogenetically, FCV-U1 clearly separated from other FCV strains in phenograms based on nonhypervariable regions. In contrast, FCV-U2 consistently segregated with the Urbana strain in all phenograms. Clustering of isolates by geographic origin was most apparent in phenograms based on nonhypervariable regions. No clustering of isolates by biotype was apparent in any phenograms. Our results indicate that FCV-UI and FCV-U2 are genetically distinct from other known vaccine and field strains of FCV.     

Bacteriuria in cats with feline lower urinary tract disease: a clinical study of 134 cases in Norway

Feline lower urinary tract disease (FLUTD) is considered to be one of the most common diagnoses in feline patients. Several authors have concluded that feline idiopathic cystitis is the most common cause of FLUTD, whereas infectious cystitis is diagnosed in only 2% of the cases. In the period from January 2003 to February 2005, 134 cats that presented with signs of lower urinary tract disorders were included in a study at the Norwegian School of Veterinary Science. Ninety-seven percent were first opinion cases. All the cats went through a physical examination, and blood samples were collected for haematology and clinical chemistry. The urine analysis included urine stix, specific gravity, microscopic examination of the sediment and microbiological culturing. The urine samples were collected as voided mid-stream urine samples, by catheter or by cystocentesis and the method used was registered. Of the 134 cats included in the study, 37% were diagnosed as having obstructive and 63% as having non-obstructive FLUTD. In total 44 cats (33%) were diagnosed with bacteriuria, exceeding 10(3) colony forming units per millilitre (cfu/ml) and 33 (25%) of these cats had bacterial growth exceeding 10(4) cfu/ml, either alone or in combination with crystals and/or uroliths. Six cats (18%) with bacterial growth exceeding 10(4) cfu/ml were older than 8 years. No significant difference was found between the sampling methods performed with regard to bacteriuria. This study indicates that bacteriuria may have been underdiagnosed in Norwegian cats with clinical signs of FLUTD. It also confirms the importance of microbiological culturing in first opinion cases with FLUTD and that a skilled operator can get representative samples regardless the choice of method.     

Prevalence of bacterial species in cats with clinical signs of lower urinary tract disease: recognition of Staphylococcus felis as a possible feline urinary tract pathogen

This study investigated the prevalence of bacterial pathogens of the urinary tract in Australian cats. Urine was collected by cystocentesis and subjected to urinalysis, bacterial culture and susceptibility testing. A total of 126 isolates were obtained from 107 culture-positive cats. Escherichia coli was most commonly isolated (37.3% of isolates) with the majority of isolates showing susceptibility to the 14 antimicrobials tested. Just over a quarter of isolates (27.0%) were Enterococcus faecalis, which showed resistance to cephalosporins and clindamycin. Staphylococcus felis, a previously unreported feline urinary tract pathogen which was susceptible to all antimicrobial agents tested, comprised 19.8% of the isolates. S. felis was significantly associated with urine that had a higher specific gravity (p=0.011) and pH (p=0.006) and was more likely to contain crystals (p=0.002) than urine from which other bacterial species were isolated. This is the first published study that associates the isolation of S. felis with clinical signs of lower urinary tract disease in cats.     

Clinical evaluation of cats with lower urinary tract disease.

In a prospective study, 141 cats with hematuria, dysuria, urethral obstruction, or combinations of these signs were evaluated by contemporary diagnostic methods and compared with 26 clinically normal cats (controls). Specific diagnosis was established in 45% (64/141) of cats affected with lower urinary tract disease (LUTD). Crystalline matrix plug-induced urethral obstruction was diagnosed in 21% (30/141) of affected cats, uroliths were identified in 21% (30/141) of affected cats, uroliths with concomitant bacterial urinary tract infection (UTI) were identified in less than 2% (2/141) of affected cats, and bacterial UTI alone was identified in less than 2% (2/141) of cats with LUTD. Viruses, mycoplasmas, and ureaplasmas were not isolated from urine samples collected from affected or control cats. Bovine herpesvirus 4 (BHV-4)-neutralizing antibodies were not detected in any serum sample obtained from cats with LUTD or from control cats. In contrast, BHV-4 antibodies were detected by an indirect immunofluorescent antibody (IFA) test in sera obtained from 31% (44/141) of cats with LUTD and 23% (6/26) of control cats. The prevalence of positive BHV-4 IFA test results in affected cats was not significantly different from that observed in control cats. Significant association was not apparent between positive BHV-4 IFA test results and clinical diagnosis, abnormal laboratory findings, or cat age. However, the number of male cats with BHV-4 IFA titer was significantly (P less than 0.02, chi 2 test) greater than that of female cats. Detection of BHV-4 antibodies in approximately 30% of affected and control cats indicates prior virus exposure. Further investigations are warranted to clarify the specific role of BHV-4 in cats with naturally acquired LUTD.     

The short-term clinical efficacy of amitriptyline in the management of idiopathic feline lower urinary tract disease: a controlled clinical study

In a controlled study, the effects of amitriptyline compared with that of a placebo in cats suffering from idiopathic Feline Lower Urinary Tract Disease (FLUTD) have been investigated. Thirty-six animals were selected by veterinary practitioners and treated with a placebo or 10mg amitriptyline once daily. All animals received concomitant antibiotic treatment. A total of 24 cats were included in the final assessment of the results. The severity of symptoms before and after treatment were compared between groups and showed no significant difference. Results indicated that the 7-day course of 10mg amitriptyline was not effective in the treatment of idiopathic FLUTD. Thus, it is considered not to be beneficial as a short-term therapy where the therapeutic results depend on peripheral effects of the drug. Long-term effects may be expected 4 or more weeks after the start of therapy and need to be further investigated.