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.     

Diagnosis of hyperthyroidism in cats with mild chronic kidney disease

OBJECTIVES: In cats with concurrent hyperthyroidism and non-thyroidal illnesses such as chronic kidney disease, total thyroxine concentrations are often within the laboratory reference range (19 to 55 nmol/l). The objective of the study was to determine total thyroxine, free thyroxine and/or thyroid-stimulating hormone concentrations in cats with mild chronic kidney disease. METHODS: Total thyroxine, free thyroxine and thyroid-stimulating hormone were measured in three groups. The hyperthyroidism-chronic kidney disease group (n=16) had chronic kidney disease and clinical signs compatible with hyperthyroidism but a plasma total thyroxine concentration within the reference range. These cats were subsequently confirmed to be hyperthyroid at a later date. The chronic kidney disease-only group (n=20) had chronic kidney disease but no signs of hyperthyroidism. The normal group (n=20) comprised clinically healthy senior (>8 years) cats. RESULTS: In 4 of 20 euthyroid chronic kidney disease cats, free thyroxine concentrations were borderline or high (> or =40 pmol/l). In the hyperthyroidism-chronic kidney disease group, free thyroxine was high in 15 of 16 cats, while thyroid-stimulating hormone was low in 16 of 16 cats. Most hyperthyroidism-chronic kidney disease cats (14 of 16) had total thyroxine greater than 30 nmol/l, whereas all the chronic kidney disease-only cats had total thyroxine less than 30 nmol/l. CLINICAL SIGNIFICANCE: The combined measurement of free thyroxine with total thyroxine or thyroid-stimulating hormone may be of merit in the diagnosis of hyperthyroidism in cats with chronic kidney disease.     

Randomized controlled trial of the efficacy of short-term amitriptyline administration for treatment of acute,nonobstructive, idiopathic lower urinary tract disease in cats

OBJECTIVE: To determine whether short-term amitriptyline administration would be efficacious in the treatment of acute, nonobstructive, idiopathic lower urinary tract disease in cats. DESIGN: Randomized controlled trial. ANIMALS: 31 untreated male and female cats with acute, nonobstructive, idiopathic lower urinary tract disease. PROCEDURES: Cats were treated with amitriptyline (5 mg/d; n = 16) or a placebo (15) for 7 days and monitored for pollakiuria, hematuria, and adverse events. Cats were reexamined 1 month after treatment, and owners were interviewed by telephone 6, 12, and 24 months after treatment. RESULTS: 2 amitriptyline-treated cats were excluded from analyses because of acquired urinary tract infection. Clinical signs resolved by day 8 in 8 amitriptyline-treated and 10 control cats. There were no apparent differences in likelihood or rate of recovery from pollakiuria or hematuria between groups. Overall, clinical signs recurred significantly faster and more frequently in amitriptyline-treated than control cats. However, after excluding recurrences within 21 days of treatment, risk of recurrence was similar in both groups. Increasing age was significantly associated with increased likelihood and rate of recovery from hematuria and with decreased risk of recurrence of signs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that short-term amitriptyline treatment has no benefit in terms of resolution of pollakiuria and hematuria in cats with idiopathic lower urinary tract disease and may be associated with an increased risk of recurrence.     

Ocular lesions associated with systemic hypertension in cats: 69 cases (1985-1998)

OBJECTIVE: To characterize clinical and clinicopathologic findings, response to treatment, and causes of systemic hypertension in cats with hypertensive retinopathy. DESIGN: Retrospective study. ANIMALS: 69 cats with hypertensive retinopathy. PROCEDURE: Medical records from cats with systemic hypertension and hypertensive retinopathy were reviewed. RESULTS: Most cats (68.1%) were referred because of vision loss; retinal detachment, hemorrhage, edema, and degeneration were common findings. Cardiac abnormalities were detected in 37 cats, and neurologic signs were detected in 20 cats. Hypertension was diagnosed concurrently with chronic renal failure (n = 22), hyperthyroidism (5), diabetes mellitus (2), and hyperaldosteronism (1). A clearly identifiable cause for hypertension was not detected in 38 cats; 26 of these cats had mild azotemia, and 12 did not have renal abnormalities. Amlodipine decreased blood pressure in 31 of 32 cats and improved ocular signs in 18 of 26 cats. CONCLUSIONS AND CLINICAL RELEVANCE: Retinal lesions, caused predominantly by choroidal injury, are common in cats with hypertension. Primary hypertension in cats may be more common than currently recognized. Hypertension should be considered in older cats with acute onset of blindness; retinal edema, hemorrhage, or detachment; cardiac disease; or neurologic abnormalities. Cats with hypertension-induced ocular disease should be evaluated for renal failure, hyperthyroidism, diabetes mellitus, and cardiac abnormalities. Blood pressure measurements and funduscopic evaluations should be performed routinely in cats at risk for hypertension (preexisting renal disease, hyperthyroidism, and age > 10 years). Amlodipine is an effective antihypertensive agent in cats.     

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.     

Efficacy and safety of cefovecin for the treatment of urinary tract infections in cats

OBJECTIVES: To determine the efficacy and safety of cefovecin (Convenia); Pfizer Animal Health) in the treatment of urinary tract infections in cats. METHOD: A multi-centre, masked, randomised study was conducted in cats presenting with clinical signs indicative of urinary tract infections. Cephalexin (Rilexine); Virbac) administered orally twice daily at 15 mg/kg bodyweight for 14 days was compared with a single subcutaneous injection of cefovecin in cats. The primary efficacy parameter assessed was bacterial elimination of the pretreatment uropathogen. RESULTS: Four hundred and thirty-four cats were screened for urinary tract infections. One hundred and eighty-five cats were treated with either cefovecin (n=124) or cephalexin (n=61). Ninety-seven cats (22.2 per cent) had confirmed bacteriuria and 82 cats were included in efficacy analysis. Escherichia coli was eliminated in 76.7 per cent (23 of 30) of cefovecin-treated cats compared with 62.5 per cent (10 of 16) of cephalexin-treated cats. Cefovecin demonstrated statistical non-inferiority compared with cephalexin for bacterial elimination. There were no suspected adverse drug reactions attributable to treatment with cefovecin or cephalexin. CLINICAL SIGNIFICANCE: Cefovecin was demonstrated to be an effective and safe treatment for urinary tract infections.     

High urinary corticoid/creatinine ratios in cats with hyperthyroidism

Measurement of the urinary corticoid : creatinine (C : C) ratio provides an assessment of cortisol secretion over a period of time. Therefore, this test is a very sensitive measure of adrenocortical function. The stress of the diagnostic procedure and nonadrenal disease may increase the urinary C : C ratio. In addition, diseases such as hyperthyroidism may influence the metabolic clearance of cortisol. To evaluate the effect of thyroid hormone excess, urinary C : C ratios were measured in 32 cats with hyperthyroidism and 45 healthy household cats. In 7 cats, urinary C : C ratios were measured both before and after treatment for hyperthyroidism. With data from the healthy cats, the reference range for the urinary C : C ratio was determined to be 8.0 to 42.0 X 10(-6). The urinary C : C ratios in the cats with hyperthyroidism (median, 37.5 x 10(-6); range, 5.9-169.5 x 10(-6)) were significantly (P = .001) higher than those in the healthy cats (median, 16 x 10(-6); range, 4.8-52.5 x 10(-6)). In 15 cats with hyperthyroidism, the urinary C : C ratios exceeded the upper limit of the reference range. Treatment for hyperthyroidism led to a marked decrease in urinary C : C ratios. The results of this study demonstrate that the urinary C : C ratio may be abnormally high in cats with hyperthyroidism, probably because of increased metabolic clearance of cortisol and activation of the pituitary-adrenocortical axis by disease. Although the clinical features of hyperthyroidism and hyperadrenocorticism in cats are different, hyperthyroidism should be ruled out when cats are suspected of hyperadrenocorticism on the basis of abnormally high urinary C : C ratios.     

Clinical features and risk factors for development of urinary tract infections in cats

The clinical and diagnostic features of 155 cats with urinary tract infection (UTI) and 186 controls with negative urine culture/s were characterized retrospectively (signalment, clinical signs, urinalysis, urine culture, concurrent diseases, lower urinary tract diagnostic/therapeutic procedures). Multivariable logistic regression was used to identify risk factors associated with UTI. Cats of all ages were affected by UTI with no sex/breed predisposition. Lower urinary tract signs were absent in 35.5% of cats with UTI. Pyuria and bacteriuria had sensitivities of 52.9% and 72.9%, and specificities of 85.5% and 67.7% for detection of UTI, respectively. Risk factors significantly associated with increased odds of UTI were urinary incontinence [odds ratio (OR) = 10.78, P = 0.0331], transurethral procedures (OR = 8.37, P <0.0001), urogenital surgery (OR = 6.03, P = 0.0385), gastrointestinal disease (OR = 2.62, P = 0.0331), decreased body weight (OR = 0.81, P = 0.0259) and decreased urine specific gravity (OR = 0.78, P = 0.0055). Whilst not independently significant, renal disease and lower urinary tract anatomic abnormalities improved statistical model performance and contributed to UTI.     

Frequency and risk factors for urinary tract infection in cats with diabetes mellitus

BACKGROUND: Identification and control of infections are important in the management of diabetic cats. Urinary tract infections have not been well characterized in diabetic cats. This retrospective study was performed to review and characterize urinary tract infections in diabetic cats. HYPOTHESIS: Urinary tract infections are common in diabetic cats. ANIMALS: A review was made of the medical records of 141 diabetic cats that had had urine obtained for culture by antepubic cystocentesis and that had not been treated with antibiotics, undergone urinary tract catheterization or urinary tract surgery within 2 weeks of urine collection or had urethral obstruction at the time of urine collection. METHODS: A review of medical records. RESULTS: Urinary tract infection was identified in 18 of 141 diabetic cats. Escherichia coli was the most common isolate (67%). Female cats were at increased risk (prevalence odds ratios [POR], 3.7; 95% confidence interval [CI], 1.3 to 10.2; P = .013). Clinical signs of lower urinary tract disease and findings on urine sediment examination were good predictors of positive urine cultures. CONCLUSIONS AND CLINICAL IMPORTANCE: Urinary tract infections are common in diabetic cats regardless of status of diabetic control, suggesting routine monitoring with urine sediment exams or urine culture is warranted.     

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.     

Feline immunodeficiency virus: prevalence, disease associations and isolation

Of 467 cat serums tested for antibody to feline immunodeficiency virus (FIV) 120 (26%) were positive. The average age of positive cats was 7.5 years (range 1 to 16 years), and 67% were male. Of 110 serums collected in 1980, 27 (24.5%) were positive. A wide variety of clinical signs including oral cavity disease, anorexia, weight loss, lethargy, depression, fever, respiratory and urinary tract disease, conjunctivitis, abscesses, anaemia and lymphadenopathy were observed in the cats with serum antibody. There was often a history of chronic disease or recurrence of particular or various clinical signs in these cats. FIV was isolated from 4 of 8 FIV antibody positive cats by cocultivation of patient lymphocytes with donor lymphocytes in the presence of interleukin 2.     

Clinical and pathologic features of endometrial hyperplasia, pyometra, and endometritis in cats: 79 cases (1980-1985)

Records of 79 cats determined to have endometrial hyperplasia (EH) with or without pyometra or endometritis were studied. Forty-eight cats (61%) were spayed or died because of complications relating to reproductive tract disease. All other cats were free of clinical signs of disease, and lesions were found incidentally during routine ovariohysterectomy or at necropsy. Prevalence of uterine lesions was greater in cats greater than or equal to 5 years old. Breeding, age at first breeding, and queening could not be correlated with clinical or pathologic signs of disease. Seventy-one percent (34/48) of cats with clinical signs referable to the reproductive tract had histologic evidence of pyometra or endometritis, whereas only 19% (6/31) of cats without clinical signs had histologic evidence of either disease. Only 23% (9/39) of cats without pyometra or endometritis had corpora lutea (CL) in at least one ovary, whereas 40% (16/40) of cats with either pyometra or endometritis had CL. We concluded that the prevalence of EH in cats increases with age in sexually intact female cats, and that most cases of pyometra or endometritis, but not EH, in cats are associated with retained CL.     

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 .     

Survival and the Development of Azotemia after Treatment of Hyperthyroid Cats

Background: Hyperthyroidism complicates the diagnosis of chronic kidney disease (CKD) as it increases glomerular filtration rate. No practical and reliable means for identifying those cats that will develop azotemia after treatment for hyperthyroidism has been identified. Hyperthyroidism is associated with proteinuria. Proteinuria has been correlated with decreased survival of cats with CKD and with progression of CKD. Hypothesis: Proteinuria and other clinical parameters measured at diagnosis of hyperthyroidism will be associated with the development of azotemia and survival time. Animals: Three hundred client owned hyperthyroid cats treated in first opinion practice. Methods: Retrospective, cohort study relating clinical parameters in hyperthyroid cats at diagnosis to the development of azotemia within 240 days of diagnosis and survival time (all cause mortality). Multivariable logistic regression analysis was used to identify factors that were predictive of the development of azotemia. Multivariable Cox regression analysis was used to identify factors associated with survival. Results: Three hundred cats were eligible for survival analysis and 216 cats for analysis of factors associated with the development of azotemia. The median survival time was 417 days, and 15.3% (41/268) cats developed azotemia within 240 days of diagnosis of hyperthyroidism. Plasma concentrations of urea and creatinine were positively correlated with the development of azotemia. Plasma globulin concentration was negatively correlated with the development of azotemia. Age, urine protein : creatinine ratio, and the presence of hypertension were significantly correlated with decreased survival time. Urine specific gravity and PCV were significantly correlated with increased survival time. Conclusions and Clinical Importance: The proteinuria associated with hyperthyroidism is not a mediator of progression of CKD; however, it does correlate with all cause mortality.     

Perineal urethrostomy versus dietary management in prevention of recurrent lower urinary tract disease

The frequency and cause of recurrent lower urinary tract disease was compared prospectively in three groups of 10 male cats during a one year period following correction of obstructive urethropathy caused by matrix-crystalline plugs. One group of cats was managed by perineal urethrostomy, one group with a calculolytic diet, and the third group by perineal urethrostomy and the calculolytic diet. Ten episodes of bacterial urinary tract infection developed in five of 10 cats with perineal urethrostomies; six episodes of bacterial urinary tract infection developed in four of 10 cats with perineal urethrostomies and consuming the calculolytic diet. Bacterial urinary tract infections were not observed in cats managed only with the calculolytic diet. Staphylococcal-induced struvite urocystoliths developed in two cats with perineal urethrostomies. Vesicourachal diverticula detected in nine cats at the time of diagnosis of urethral obstruction healed spontaneously following restoration of urethral patency and remission of clinical signs. Transient microscopic haematuria was observed in approximately 25 per cent of the cats in all three treatment groups during the one year study. Results of this study confirm the effectiveness of dietary management in prevention of recurrent urethral obstruction caused by struvite-containing urethral precipitates, and verify that recurrent signs of lower urinary tract disease in cats may be caused by agents that are different from those that initiate the problem. They also confirm that perineal urethrostomies predispose cats to recurrent ascending bacterial urinary tract infections.     

Effects and safety of iopanoic acid in cats administered levothyroxine

The purpose of this study was to evaluate the safety and effect of iopanoic acid in 13 cats with hyperthyroidism induced by daily subcutaneous administration of 25microg/kg levothyroxine for a period of 42 days. On day 28 of levothyroxine administration, cats were randomly allocated to receive treatment twice daily with a placebo (control group; n=4), 50mg iopanoic acid (low dose group; n=5), or 100mg iopanoic acid (high dose group; n=4) for 14 days. Compared to the control group, T(3) concentrations were significantly decreased in both the low dose and high dose groups on days 35 and 42. T(3) concentrations in the low dose and high dose groups at days 35 and 42 were not different from day -8. The effect of iopanoic acid on clinical signs of hyperthyroidism was less apparent. Further clinical studies evaluating the long-term effect in cats with spontaneous hyperthyroidism are warranted.     

Occurrence of Problems after Three Techniques of Bilateral Thyroidectomy in Cats

Bilateral thyroidectomy was performed in 106 cats with hyperthyroidism by one of three techniques: original intracapsular, modified intracapsular, or modified extracapsular. Hypocalcemia was detected in the first 3 days after surgery in 11 (22%) of 50 cats treated by the intracapsular technique, 10 (33%) of 30 cats treated by the modified intracapsular technique, and 6 (23%) of 26 cats treated by the modified extracapsular technique. Hypocalcemia was classified as mild or severe. No signs of hypoparathyroidism developed in any of the 13 cats with mild hypocalcemia. Of the 14 cats with severe hypocalcemia, 8 had clinical signs of hypoparathyroidism before and during treatment with calcium and vitamin D, 3 were treated and no clinical signs developed, 2 were not treated but no clinical signs developed, and 1 was lost to follow-up. No cat required permanent calcium or vitamin D supplementation after surgery. Severe hypocalcemia and clinical signs of hypoparathyroidism occurred in 3 (6%) of the 50 cats treated by the intracapsular technique, 4 (13.3%) of the 30 cats treated by the modified intracapsular technique, and 1 (3.8%) of the 26 cats treated by the modified extracapsular technique. Twelve cats had recurrence of hyperthyroidism at a median time of 23 months. The intracapsular technique was used in 11 of these cats, and the modified extracapsular technique was used in 1. No clinical signs of hypothyroidism were detected in any of the cats. The modified intracapsular and modified extracapsular techniques of bilateral thyroidectomy are effective procedures for the treatment of feline hyperthyroidism.     

Transpelvic urethrostomy in 11 cats using an ischial ostectomy

OBJECTIVE: To investigate the feasibility and long-term outcome of a modified subpubic urethrostomy technique termed transpelvic urethrostomy (TPU) in cats. STUDY DESIGN: Prospective clinical study. ANIMALS: Eleven male cats with obstructive lower urinary tract disease that could not be relieved, and requiring a surgical urinary diversion, were selected for TPU. METHODS: With the cat in dorsal recumbency, the penis was exposed and the ventral pelvis was denuded by median adductor muscle elevation. An approximately 12 mm x 15 mm area of ischium was removed. The pelvic urethra, 8-20 mm cranial to the bulbourethral glands, was incised longitudinally and sutured to the skin to create a urethrostomy. RESULTS: All cats were neutered males (2-9 years); none were uremic or hyperkalemic at admission. Urine was cultured if there was leukocyturia, nitrituria, and/or bacteriua. Bacteria were isolated from 2 specimens. A patent urethrostomy was created in all cats without operative complications. Except for 1 cat without associated clinical signs, stricture was not evident between 9 and 42 months after urethrostomy. One cat had postoperative urinary incontinence (UI) that resolved within 4 weeks. Two cats each had 1 episode of idiopathic lower urinary tract disease after 6-month follow-up; both responded to medical therapy. CONCLUSIONS: TPU was used as a successful urinary diversion procedure relieving signs of urinary tract obstruction and preventing further obstruction, with few complications. The incidence of UI after TPU remains minimal. CLINICAL RELEVANCE: TPU should be considered as a salvage urinary diversion procedure in cats (as an alternative to prepubic and subpubic techniques). TPU may also be considered as a possible primary urinary diversion solution (an alternative to perineal urethrostomy) for obstructive lower urinary tract disease in cats.     

Adverse events in 50 cats with allergic dermatitis receiving ciclosporin

Ciclosporin is an immunosuppressive drug that has been used to treat allergies and other immune-mediated diseases in cats, dogs and humans. Information about the adverse effects of ciclosporin in cats has been limited to smaller studies and case reports. Adverse effects in dogs are mainly gastrointestinal in nature, but humans can also experience hypertension and altered renal function. The aim of this retrospective case series study was to document the occurrence and clinical appearance of adverse events in cats receiving ciclosporin to treat allergic skin disease. The medical records of 50 cats with allergic dermatitis treated with oral ciclosporin (1.9-7.3 mg/kg/day) were reviewed. Adverse events occurred in 66% (33 cats). Adverse events likely to be associated with ciclosporin included the following: vomiting or diarrhoea within 1-8 weeks of receiving ciclosporin (24%), weight loss (16%), anorexia and subsequent hepatic lipidosis (2%) and gingival hyperplasia (2%). Other adverse events less likely to be associated with ciclosporin therapy included the following: weight gain (14%), dental tartar and gingivitis (10%), otitis (4%), chronic diarrhoea (4%), inflammatory bowel disease with indolent gastrointestinal lymphoma (2%), urinary tract infection (2%), cataract (2%), elevated liver enzymes (2%), hyperthyroidism and renal failure (2%) and transient inappropriate urination (2%). Some cats experienced multiple adverse events. Case-control studies are needed to prove cause and effect of ciclosporin with regard to these adverse events.