The role of uropathogens in feline lower urinary tract disease. Clinical implications

Urinary capillariosis in a cat from Rio de Janeiro, Brazil - Clinical, morphological and phylogenetic characterization

Capillaria spp. infections of the urinary tract of domestic carnivores are uncommon worldwide. Infections are rarely diagnosed and are typically asymptomatic. This study aimed to evaluate a case of capillariosis in a cat from the state of Rio de Janeiro, Brazil. A seven-year-old female cat with apathy and reduced appetite was presented. Urine analysis revealed C. plica eggs in urine sediment, and cystitis was evidenced by the presence of bacteria, pyuria, proteinuria and hematuria. The subject was treated with 50 mg/kg fenbendazole for five days. Urine samples were frozen for molecular analysis and species confirmation. Polymerase chain reaction for amplification of the 18S rRNA gene followed by sequencing confirmed the occurrence of Capillaria sp. There has been limited phylogenetic study of Capillaria spp. in cats, so further studies are needed to identify the species present in different locations and associated with feline pathogenesis.

Epidemiological and pathological study of feline morbillivirus infection in domestic cats in Japan

BACKGROUND

Feline morbillivirus (FmoPV) is a novel paramyxovirus found to infect domestic cats. FmoPV has been isolated in several countries in Asia and Europe and is considered to have genetic diversity. Also, it is suspected to be associated with feline renal diseases including tubulointerstitial nephritis (TIN), which affects domestic cats with a high incidence rate.

RESULTS

To clarify the state of FmoPV infection among domestic cats in Japan, an epidemiological survey was conducted. Twenty-one out of 100 cats were found to have serum antibodies (Ab) against FmoPV-N protein by indirect immunofluorescence assay (IF) using FmoPV-N protein-expressing HeLa cells. Twenty-two of the cats were positive for FmoPV RNA in the urine and/or renal tissues. In total, 29 cats were positive for Ab and/or viral RNA. These FmoPV-infected cats were classified into three different phases of infection: RNA+/Ab + (14 cats), RNA+/Ab- (8 cats) and RNA-/Ab + (7 cats). In immunohistochemistry (IHC), 19 out of 29 cats were positive for FmoPV-N protein in kidney tissues; however, the FmoPV-N protein was located in the inflammatory lesions with severe grade in only four out of the 19 cats. Since 15 out of 29 infected cats were positive for viral RNA and Ab, approximately half of the infected cats were persistently infected with FmoPV.

CONCLUSIONS

A statistically significant difference was observed between infection of FmoPV and the presence of inflammatory changes in renal lesions, indicating a relationship between FmoPV infection and feline renal diseases. However, we could not obtain histopathological evidence of a relationship between FmoPV infection and TIN.

Urinary capillariosis in six dogs from Italy

Canine urinary capillariosis is caused by the nematode Pearsonema plica. P. plica infection is seldomly detected in clinical practice mainly due to diagnostic limitations. This report describes six cases of urinary capillariosis in dogs from Italy. Recurrent cystitis was observed in one dog, whereas another patient was affected by glomerular amyloidosis. In the remaining animals, the infection was considered an incidental finding. Immature eggs of the parasite were observed with urine sediment examination in 3/6 patients. Increased awareness of the potential pathogenic role of P. plica and clinical disease presentation could help identify infected animals.

Follow-up protein profiles in urine samples during the course of obstructive feline idiopathic cystitis

Feline idiopathic cystitis (FIC) is a common lower urinary tract disorder in cats, which often recurs. Published reports document increased urine fibronectin and thioredoxin concentrations in cats with FIC compared with healthy control cats. Therefore, these proteins might be of interest in the pathophysiology of FIC. The purpose of the present study was to evaluate variations in these urine proteins throughout the course of FIC by assessing their concentrations in urine specimens from cats with a history of obstructive FIC. Urine total protein (TP) was measured using the Bradford assay, while urine fibronectin and thioredoxin concentrations were determined by Western blot analysis. Urine TP was significantly higher in cats with obstructive FIC at presentation (day 0) than in healthy control cats (P<0.01). There were significant decreases in urine TP in cats with obstructive FIC after 3 months (P<0.01). Significantly higher urine fibronectin (P<0.01) and thioredoxin (P<0.05) concentrations were demonstrated in cats with FIC at day 0 compared to control cats, but there was no significant change over time (P>0.05). Increased concentrations of these proteins over time might reflect ongoing structural and pathological alterations to functional processes in the urinary bladders of cats with obstructive FIC.

Symptomatic Capillaria plica infection in a young European cat

An 8-month-old owned European cat showing abdominal pain, fever, distended painful bladder and urinary blockage was presented. Intravenous fluids were immediately administered and, after sedation, a urinary catheter was applied. Blood and urine analysis revealed cystitis and a moderate-to-severe degree of renal failure. About 20 thread-like nematodes, identified as Capillaria plica larvae and fragments of adult stages, were found in the urine sediment. After treatment with an oral formulation of fenbendazole at 25 mg/kg q 12 h for 10 days, urinary signs and bladder worms disappeared. Cases of Capillaria species bladder worms in cats are rarely reported and most infected cats show no clinical signs, presumably because of a low parasite burden. In the present study, feline capillariosis was associated to urethral obstruction, severe difficulties in urination, cystitis and renal failures.

Idiopathic cystitis in domestic cats--beyond the lower urinary tract

Signs of lower urinary tract (LUT) disease in domestic cats can be acute or chronic, and can result from variable combinations of abnormalities within the lumen of the LUT, the parenchyma of the LUT itself, or other organ system(s) that then lead to LUT dysfunction. In the majority of cats with chronic signs of LUT dysfunction, no specific underlying cause can be confirmed after standard clinical evaluation of the LUT, so these cats typically are classified as having idiopathic cystitis. A syndrome in human beings commonly known as interstitial cystitis (IC) shares many features in common with these cats, permitting comparisons between the two species. A wide range of similarities in abnormalities has been identified between these syndromes outside as well as inside the LUT. A variety of potential familial and developmental risk factors also have been identified. These results have permitted generation of the hypothesis that some of these people have a disorder affecting the LUT rather than a disorder of the LUT. This perspective has suggested alternative diagnostic strategies and novel approaches to treatment, at least in cats. The purpose of this review is to summarize research investigations into the various abnormalities present in cats, to compare some of these findings with those identified in human beings, and to discuss how they might modify perceptions about the etiopathogenesis, diagnosis, and treatment of cats with this disease. Dedication: I dedicate this contribution to Professor Dennis J. Chew, whose collaboration, patience, and support made it all possible.

Fungal urinary tract infections in the dog and cat: a retrospective study (2001-2004)

Thirty-five animals (23 dogs, 12 cats) with fungal urinary tract infections (UTIs) were retrospectively studied. Dysuria, hematuria, increased frequency of micturition, anorexia, depression, and pyrexia were the most common clinical signs noted. Seven species of fungi were identified in the affected animals. Candida albicans was the most common isolate. Most animals diagnosed with fungal UTI also had other concurrent urinary tract or medical problems. Lower urinary tract diseases, diabetes mellitus, neoplasia, and renal failure were the most common concurrent or preceding diseases identified. Resolution of fungal UTI occurred in 12 animals that received specific antifungal treatment.

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.

Urinary tract infection: the role of canine transmissible venereal tumour

The role of transmissible venereal tumours in the pathogenesis of urinary tract infection in dogs was investigated in 86 dogs. Fifty-five had transmissible venereal tumours, and the remaining 31 animals were used as controls. A thorough clinical examination of the external genitalia was carried out in each case. In the dogs with transmissible venereal tumours, the sites of attachment were recorded. Urine samples were taken by cystocentesis and the external genitalia swabbed; the samples were cultured for bacteria using standard methods. Tumours were found on the prepuce and other parts of the penis in male dogs; in bitches they were found in the vagina, vestibule or the vestibulovaginal junction. Dogs with transmissible venereal tumours were found to be at a high risk of having bacteriuria (odds ratio [OR] = 7.04). Obliteration of the urethral orifice by the tumour, possibly leading to urine retention, was thought to be the main reason for the high incidence of urinary tract infection among dogs with transmissible venereal tumours. Long-standing cases of transmissible venereal neoplasia had a higher chance of becoming bacteriuric compared with recent cases (OR = 29.60). This study indicates that transmissible venereal tumour may be a predisposing factor for the development of urinary tract infection.