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.     

Herpesvirus induced feline urolithiasis--a review.

Three viruses were isolated during early studies of feline urolithiasis. These viruses were: feline calicivirus, feline syncytium forming virus (FeSFV), and a previously undescribed cell associated herpesvirus (CAHV).Urolithiasis in all its manifestations (hematuria, urethral obstruction, and cystitis) has been reproduced in specific pathogen free (SPF) male cats following inoculation with the herpesvirus alone. The disease has not been induced in SPF cats with the calicivirus alone. However, when SPF cats were inoculated with both the CAHV and calicivirus, clinical signs of disease developed earlier and more urinary tract disease complications were produced. From these results, it is postulated that the calicivirus may act as an enhancing or complicating factor in the development of the disease. Because urolithiasis was produced in SPF cats without the FeSFV, it is further postulated that this virus either may have no role in pathogenesis of the disease, or it too may produce secondary complications.     

Evaluation of clinical signs and causes of lower urinary tract disease in European cats

OBJECTIVES: To investigate the clinical signs and causes of lower urinary tract disease (LUTD) in 77 cats. METHODS: Cats diagnosed with LUTD over a two-year period were included in the study. RESULTS: The study population comprised 67 male and 10 female cats. Uroliths occurred in 17 of the 77 cats (22 per cent), urethral plugs in eight cats (10 per cent) and urinary tract infection in six cats (8 per cent). In 44 cats (57 per cent), no specific cause for the disease was found and they were classified as having idiopathic LUTD. In two of the 77 cats (3 per cent) no definitive diagnosis was established. Pain was less common in cats with uroliths and haematuria was more often seen in cats with urinary tract infection. At presentation, urethral obstruction was diagnosed in 45 of the 77 cats (58 per cent). CLINICAL SIGNIFICANCE: The causes of LUTD found in cats in this study are similar to those that have been previously documented, and idiopathic LUTD is the most frequent diagnosis. However, the rate of urethral obstruction, particularly in cats with idiopathic LUTD, was higher than in other reports. The cause of this difference is unknown.     

Nutrition and aspects of feline lower urinary tract disease

Important causes of feline lower urinary tract disease (LUTD) that have been identified include urolithiasis and the formation of urethral plugs. In many cases, however, no specific cause of disease may be evident. Clinical studies in cats with apparently ‘idiopathic’ feline LUTD have suggested that some cases may respond to dietary modification, with diets designed to acidify urine, provide a good urine volume and relatively restricted magnesium intake. Nutritional research has predominantly focused on factors that may contribute to the formation of struvite uroliths, and has resulted in the development of specific recommendations for the management and subsequent prevention of recurrence of this condition. Urethral plugs have been less well studied, although recent clinical observations provide evidence that dietary modification may be of value in preventing their recurrence.     

Genetic and serologic analysis of feline cell-associated herpesvirus-induced infection of the urinary tract in conventionally reared cats

The genetic and antigenic nature of feline cell-associated herpesvirus (FeCAHV) was characterized by use of DNA restriction endonuclease analysis, and direct and indirect fluorescent antibody (FA) techniques. Serologic responses of 6 conventionally reared cats with induced FeCAHV urinary tract infection were retrospectively evaluated, using an indirect FA test. The EcoRI, HindIII, and Pst I restriction endonuclease cleavage patterns of FeCAHV DNA were similar to those of bovid herpesvirus 4 (BHV-4; DN599 strain) DNA. Specific fluorescence was observed when FeCAHV-inoculated cell monolayers were reacted with fluorescein-conjugated BHV-4 (DN599 strain) antiserum. Conversely, specific fluorescence was also observed when feline anti-FeCAHV serum and fluorescein-conjugated caprine anti-feline IgG was reacted with BHV-4 (DN599 strain)-infected cell monolayers. At postinoculation week 10, serum antibody titer in cats with FeCAHV-induced urinary tract infection ranged from 1:2,560 to 1:10,240, as measured by use of indirect FA testing. It was concluded that FeCAHV is a member of the BHV-4 group. In addition, the FeCAHV indirect FA test provides a sensitive and specific means of evaluating FeCAHV antibody concentration in exposed cats.     

An immunofluorescence diagnostic test for feline viral rhinotracheitis.

Hyperimmune serum against feline viral rhinotracheitis was produced in a goat and conjugated with a fluorescent dye. Cell cultures infected with rhinotracheitis virus had positive immunofluorescence. Cell cultures infected with other feline viruses and herpesviruses of other species did not fluoresce. In cats experimentally infected with rhinotracheitis virus, the virus was isolated from nasal and conjunctival swabs 1 to 9 days after inoculation. Nasal smears stained with the conjugated antiserum fluoresced 1 to 9 days after inoculation when clinical disease was most apparent. Conjunctival smears had positive immunofluorescence 1 to 6 days, but not 9 days, after inoculation. On postinoculation day 23, rhinotracheitis virus was not isolated from nasal or conjunctival swabs and nasal and conjunctival smears did not fluoresce. Rhinotracheitis virus or feline calicivirus was isolated from naturally infected cats with upper respiratory tract disease. Nasal and conjunctival smears from rhinotracheitis virus-infected cats had positive immunofluorescence in all cast showing clinical illness. Smears from 1 clinically normal cat from which rhinotracheitis virus was isolated did not fluoresce. Nasal and conjunctival smears from calicivirus-infected cats did not fluoresce.     

Early events in the immunopathogenesis of feline retrovirus infections.

Feline leukemia virus and feline immunodeficiency virus (FIV) are lymphotropic retroviruses that cause a wide range of diseases in domestic cats. Although it is known that both viruses are capable of infecting T lymphocytes and that infected cats are lymphopenic, it was not known how infection with either virus might alter specific lymphocyte subpopulations. Using a panel of monoclonal antibodies to feline lymphocyte subpopulations, we examined, by use of flow cytometric analysis, lymphocyte changes in cats naturally infected with FeLV or FIV and explored the early stages in the immunopathogenesis of experimentally induced infection with these viruses. Both groups of naturally infected cats had T-cell lymphopenia. In the FIV-infected cats, the T-cell decrease was principally attributable to loss of CD4+ cells, whereas CD8+ and B-cell numbers remained normal. This led to inversion of the CD4+ to CD8+ ratio in these cats. In contrast, the T-cell lymphopenia in FeLV-infected cats resulted from decrease in CD4+ and CD8+ cells, which led to a CD4+ to CD8+ ratio within normal limits. Experimentally induced infection with these 2 viruses supported these findings. Infection with FIV induced early (10 weeks after infection), chronic inversion of the CD4+ to CD8+ ratio. In contrast, infection with FeLV did not alter CD4+ to CD8+ ratio in the first 20 weeks after infection.     

上海市宠物猫杯状病毒、疱疹病毒及流感病毒的分离与鉴定

为了解上海市猫上呼吸道疾病病例中猫杯状病毒(FCV)、猫疱疹病毒1型(FHV-1)和猫流感病毒(FIV)的感染比例及其遗传变化特点,对上海市冬季53份表现上呼吸道症状宠物猫的眼结膜、口咽和鼻黏膜拭子,进行FCV、FHV-1和FIV分离与鉴定,并对分离的病毒进行遗传进化分析.结果显示:53份样品中,FCV分离率为58.4...     

Clinicopathologic and pathologic findings of herpesvirus-induced urinary tract infection in conventionally reared cats

Clinicopathologic manifestations of induced infection of the feline lower urinary tract with bovid herpesvirus-4 (BHV-4, strain FCAHV) were characterized in 6 conventionally reared adult cats (2 sexually intact males, 2 castrated males, and 2 females). Two additional control cats were exposed with noninfected cell culture control inoculum. Clinical and radiographic signs of lower urinary tract disease were not observed in exposed or control cats. Microscopic hematuria was detected in urine samples collected by cystocentesis from 4 to 6 exposed cats and 1 of 2 control cats. Results of culture of urine for bacteria, mycoplasmas, ureaplasmas, and viruses were consistently negative. Low titer of serum BHV-4 (strain FCAHV)-neutralizing antibodies was detected in 4 of 6 exposed cats, but not in controls. Gross abnormalities of the urinary tract were not observed in any cat. Light microscopic examination of serial sections of the lower urinary tract revealed mild focal lymphoid cystitis in 2 of 6 exposed cats, one of which also had increased amounts of connective tissue and proliferation of blood vessels in the urinary bladder lamina propria. Ninety days after initial exposure, BHV-4 (strain FCAHV) was reisolated from explanted urinary bladder tissues of 5 of 6 exposed cats. Virus was not isolated from tissues of control cats. It was concluded that BHV-4 (strain FCAHV) establishes persistent urinary tract infection in conventionally reared adult male and female cats. However, persistent BHV-4 infection in cats may remain clinically inapparent.     

Viral infections and bovine mastitis: a review

This review deals with the role of viruses in the aetiology of bovine mastitis. Bovine herpesvirus 1, bovine herpesvirus 4, foot-and-mouth disease virus, and parainfluenza 3 virus have been isolated from milk from cows with clinical mastitis. Intramammary inoculations of bovine herpesvirus 1 or parainfluenza 3 virus-induced clinical mastitis, while an intramammary inoculation of foot-and-mouth disease virus resulted in necrosis of the mammary gland. Subclinical mastitis has been induced after a simultaneous intramammary and intranasal inoculation of lactating cows with bovine herpesvirus 4. Bovine leukaemia virus has been detected in mammary tissue of cows with subclinical mastitis, but whether this virus was able to induce bovine mastitis has not been reported. Bovine herpesvirus 2, vaccinia, cowpox, pseudocowpox, vesicular stomatitis, foot-and-mouth disease viruses, and bovine papillomaviruses can play an indirect role in the aetiology of bovine mastitis. These viruses can induce teat lesions, for instance in the ductus papillaris, which result in a reduction of the natural defence mechanisms of the udder and indirectly in bovine mastitis due to bacterial pathogens. Bovine herpesvirus 1, bovine viral diarrhoea virus, bovine immunodeficiency virus, and bovine leukaemia virus infections may play an indirect role in bovine mastitis, due to their immunosuppressive properties. But, more research is warranted to underline their indirect role in bovine mastitis. We conclude that viral infections can play a direct or indirect role in the aetiology of bovine mastitis; therefore, their importance in the aetiology of bovine mastitis and their economical impact needs further attention.     

Clinical evaluation of commercially available urinary acidification diets in the management of idiopathic cystitis in cats

OBJECTIVE: To compare recurrence of signs of lower urinary tract disease (LUTD) in cats with idiopathic cystitis that were fed the dry or canned formulation of a commercial diet designed to result in production of an acidic urine. DESIGN: Prospective trial. ANIMALS: 54 client-owned cats with idiopathic cystitis that was diagnosed on the basis of a history of abnormal micturition, abnormal results on urinalysis, radiography, or cystoscopy, and lack of an alternative diagnosis. PROCEDURE: Cats were assigned to be fed the canned or dry formulation of the diet. Reevaluations conducted at 2 and 16 weeks, and at 6 and 12 months included a physical examination, CBC and serum biochemical analysis (except week 2), blood gas analysis, and urinalysis. Regular telephone contacts were also made. The study was discontinued after 12 months or if signs of LUTD recurred. RESULTS: Signs of LUTD did not recur in 16 of 18 cats fed the canned diet, and 17 of 28 cats fed the dry diet (chi 2, P < 0.05). Seven cats were reevaluated at recurrence. Owners of remaining cats in which signs of LUTD recurred declined to have their pets reexamined. A different problem (bacterial urinary tract infection) was identified in only 1 cat on reevaluation. Eight cats were lost to follow-up evaluation. CLINICAL IMPLICATIONS: Feeding this commercial canned urinary acidifying diet may reduce the proportion of cats with idiopathic cystitis that will have recurrence of signs of LUTD within a 12-month period.     

Survival of a cat with pneumonia due to cowpox virus and feline herpesvirus infection

Cowpox virus infection in cats is rare and usually leads to cutaneous lesions alone. Pulmonary infection and pneumonia have been documented occasionally but all such cases described to date have been fatal. Although usually affecting the upper respiratory tract, feline herpesvirus can also induce pneumonia. The present report describes the case of a cat that recovered from a pneumonia in which both poxvirus and feline herpesvirus were demonstrated.     

Feline matrix-crystalline urethral plugs: A unifying hypothesis of causes

The hypothesis is advanced that various combinations of aetiologically different events may lead to three different, but common, clinical manifestations of feline lower urinary tract disease. One manifestation, characterised by nonobstructive haematuria, dysuria, pollakiuria, and increased production of proteinaceous and cellular inflammatory reactions occurs as a consequence of urinary tract infections with viruses and occasionally other infectious agents. A second manifestation is that of classical urolithiasis, which occurs in response to oversaturation of urine with different types of calculogenic substances. Naturally occurring feline uroliths containing magnesium ammonium phosphate, calcium oxalate, ammonium urate, calcium phosphate, cystine and xanthine have been observed. A third manifestation, resulting from the concomitant occurrence of urinary tract infections and various types of urine crystals, is characterised by formation of matrix-crystalline plugs that may obstruct the urethra, especially of male cats. Preliminary data suggest that urethral plug matrix contains Tamm-Horsfall mucoprotein, similar to that observed involved in the formation of renal tubular casts.     

Survival of equine herpesvirus-4, feline herpesvirus-1, and feline calicivirus in multidose ophthalmic solutions

Objective To determine survival over time of infectious equine herpesvirus‐4, feline herpesvirus‐1, and feline calicivirus in three commercially available and commonly used ophthalmic solutions (eyewash, fluorescein, and proparacaine HCl). Sample population Viruses used in this study were originally isolated from eyes of animals referred to the University of Illinois. Equine herpesvirus‐4 was propagated in MDBK cells and feline herpesvirus‐1 and feline calicivirus in CRFK cells. Procedure After separately inoculating a designated solution with a specific titer of an individual virus, solutions were incubated per manufacturer's recommendations, either at 4 °C or 25 °C. Virus titers within solutions were subsequently measured at 1, 8, and 24 h and 3, 5 and 7 days post inoculation using either plaque or TCID₅₀ assays. Results Equine herpesvirus‐4, feline herpesvirus‐1, and feline calicivirus were present in eyewash for 7 days, 5 days, and 7 days, respectively. Eyewash did not decrease survival time of any virus when compared to controls. Equine herpesvirus‐4 and feline herpesvirus‐1, both enveloped viruses, were not recovered at any time ≥ 1 h post inoculation in fluorescein. Feline calicivirus, a nonenveloped virus, was present in fluorescein for 7 days. Equine herpesvirus‐4 and feline herpesvirus‐1 did not remain infectious in proparacaine at any time ≥ 1 h post inoculation, but feline calicivirus was recovered at up to 24 h post inoculation. Conclusions Equine herpesvirus‐4, feline herpesvirus‐1, and feline calicivirus may be readily transmissible via the eyewash solution used in this study. Risk of iatrogenic transmission of the three viruses used in this study was significantly reduced in both fluorescein and proparacaine solutions. Feline calicivirus, the only nonenveloped virus evaluated, remained viable longer in both fluorescein and proparacaine solutions.     

A study of feline upper respiratory tract disease with reference to prevalence and risk factors for infection with feline calicivirus and feline herpesvirus.

A cross-sectional survey of a convenience sample of cats was carried out to determine the prevalence of and risk factors for respiratory tract disease, feline calicivirus (FCV) infection and feline herpesvirus (FHV) infection. Seven hundred and forty cats were studied; samples for isolation of FCV and FHV were obtained from 622 (84%). Data on individual cat and household variables were obtained by questionnaire for each cat and analysed using univariable and logistic regression analysis. Thirty-eight percent (282/740) of cats surveyed had respiratory tract disease. Eighteen of 24 predictor variables were found to be significantly (P<0.05) associated with the presence of respiratory tract disease in a cat on univariable analysis. Following logistic regression, several factors retained significance including isolation of FCV and FHV, younger cats (4-11 months of age) and multiple cat households. A negative association was found with breeding catteries and other types of household in comparison with rescue catteries. Overall, feline calicivirus was isolated from 162/622 (26%) of cats sampled; 33% of the cats with respiratory tract disease were FCV positive compared to 21% of healthy cats. Variables significantly associated with FCV isolation on logistic regression were the presence of respiratory tract disease and contact with dogs with and without respiratory tract disease. Feline herpesvirus was isolated from 30/622 (5%) of all cats sampled; 11% of cats with respiratory tract disease were FHV positive compared to 1% of healthy cats. Variables significantly associated with FHV isolation on univariable analysis included age, gender, and the presence of respiratory tract disease. Vaccination showed a negative association. Logistic regression analysis of the data for FHV was limited by the sample size and the low prevalence of FHV.     

Relationship of Lower Urinary Tract Signs to Seropositivity for Feline Immunodeficiency Virus in Cats

A group of 41 cats with signs of lower urinary tract disease was compared to a group of 41 cats without any history of disease for prevalence of seropositivity for feline immunodeficiency virus (FIV). The group of healthy cats was similar in age and gender to the group of cats with signs of lower urinary tract disease. Three of the cats with lower urinary tract disease and one control cat were seropositive for FIV.
This difference was not statistically significant. The most common cause of lower urinary tract signs was idiopathic. Only 7 cats had urinary tract infection, most associated with perineal urethrostomy or catheterization. Six of the cats with bacterial urinary tract infections were FIV negative. J Vet Intern Med 1996;10:34–38. Copyright © 1996 by the American College of Veterinary Internal Medicine .     

Evaluation of urine specific gravity and urine sediment as risk factors for urinary tract infections in cats

Background: It has been suggested that diseases that promote isosthenuria predispose to urinary tract infections because of a lack of the common bacteriostatic properties present in concentrated urine. Objectives: The purpose of this study was to assess the clinicopathologic risk factors for positive urine culture outcome in cats with chronic kidney disease (CKD), diabetes mellitus (DM), uncontrolled hyperthyroidism (HT), or lower urinary tract disease (LUTD). Methods: For this retrospective study, medical records of all cats in which a urinalysis and aerobic bacterial urine culture were performed between January 1995 and December 2002 were reviewed. Signalment, body weight, and clinicopathologic data were recorded. Based on the medical records, cats were diagnosed with CKD, DM, HT, or LUTD. Prevalence odds ratios and 95% confidence intervals were calculated using logistic regression. Multivariate models were created for each variable of interest while controlling for the confounding effect of disease group. Results: Six hundred fourteen cats met the criteria for inclusion in the study. Overall, positive urine cultures were identified in 16.9% of cats with CKD, 13.2% of cats with DM, 21.7% of cats with HT, and 4.9% of cats with clinical signs of LUTD. Decreasing urine specific gravity was not associated with positive urine culture when controlled for disease but pyuria, bacteriuria, and hematuria were all associated with positive urine culture outcome. Persians, females, increasing age, and decreasing body weight were all associated with positive urine culture outcome. Conclusions: Performing a urine culture sample based solely on the presence of isosthenuria does not seem warranted. Further studies are warranted to help identify host predisposing factors for urinary bacterial colonization in cats with these diseases.     

Experimental induction of feline viral rhinotracheitis virus re-excretion in FVR-recovered cats.

The re-excretion of feline viral rhinotracheitis (FVR) virus (feline herpesvirus I) by FVR-recovered cats is recorded both spontaneously and following a variety of stimuli, namely, corticosteroid administration, change of housing, and parturition and lactation. At least 27 of 33 (82%) FVR-recovered cats studied were shown to be viral carriers. The carrier state was characterised by periods of viral latency interspersed with episodes of viral shedding. Administration of 0-75 mg dexamethasone trimethylacetate and 2-25 mg prednisolone on days 0,2 and 4 resulted in re-excretion after a mean lag period of 7-2 days in 22 of 32 (69%) FVR-recovered cats on a total of 31 of 57 (54%) occasions. Rehousing resulted in virus re-excretion after a mean lag period of 7-2 days in four of 22 (18%) cats tested on a total of six of 40 (15%) occasions. Apparently spontaneous shedding occurred on a total of 10 occasions in nine of 31 (29%) cats during a mean observation period of 8-8 months. Four of six FVR-recovered queens in a total of four of 10 litters (40%) shed virus within two to 10 weeks of parturition. Serum neutralising antibody titres were generally boosted at the time of first re-infection but afterwards remained essentially constant. Although 82% of cats in these studies were shown to be viral carriers, only 45% of cats shed virus spontaneously or as a result of the natural stress situations and it is postulted that these naturally excreting cats are of most significance epidemiologically.