Cats and Calcium Oxalate: Strategies for managing lower and upper tract stone disease

High starch intake favours body weight control in neutered and spayed cats living in homes fed ad libitum

Different starch-to-protein ratios were compared among neutered and spayed domiciled cats. Male and female obese and non-obese cats were fed kibble diets ad libitum for 4 months high in starch (HS (38 % crude protein (CP)): starch 32 %, protein 38 %; DM basis) or high in protein (HP (55 % CP): starch 19 %, protein 55 %) but similar in energy and fat in a crossover design. Physical activity was evaluated using an accelerometer, and body composition (BC), energy expenditure (EE) and water turnover (WT) using the doubly labelled water method. Results were compared in a 2 diet × 2 sex × 2 body condition factorial arrangement. Cats fed the HS (38 % CP) diet maintained a constant body weight, but lean mass (LM) tended to be reduced in female obese but to be increased in male non-obese (P < 0·08) and increased in female non-obese cats (P = 0·01). The HP (55 % CP) diet induced an increase in cat body weight and LM (P < 0·05) without altering BC proportion. EE tended to be higher in males (351 (se 8) kJ/kg0·67/d) than females (330 (se 8) kJ/kg0·67/d; P = 0·06), was unaffected by diet or BC, decreased as age increased (R 2 0·44; P < 0·01) and increased as physical activity increased (R 2 0·58; P < 0·01). WT was higher for the HP (55 % CP) diet (P < 0·01) and increased with EE (R 2 0·65; P < 0·01). The HS (38 % CP) diet favoured body weight control during 4 months of ad libitum feeding. Caution is necessary to balance protein in diets of female obese cats over 5 years, as they may have low energy and food intake, with LM loss.

Association between serum fibroblast growth factor-23 concentrations and blood calcium levels in chronic kidney disease cats with upper urolithiasis

OBJECTIVES

This study investigated whether serum fibroblast growth factor (FGF)-23 concentrations are associated with serum total calcium (tCa) and blood ionised calcium (iCa) concentrations in cats with chronic kidney disease (CKD) and upper urolithiasis.

METHODS

Serum samples and the medical records of cats with CKD with nephroliths, ureteroliths or both were investigated retrospectively. Cats with a serum creatinine concentration >250 μmol/l and/or a serum phosphorus concentration ⩾1.50 mmol/l were excluded. Based on cut-offs for serum tCa (2.70 mmol/l) or blood iCa (1.40 mmol/l), cats were divided into the following groups: total hypercalcaemia (H-tCa) (>2.70 mmol/l) and total normocalcaemia (N-tCa) (⩽2.70 mmol/l) groups, or ionised hypercalcaemia (H-iCa) (>1.40 mmol/l) and ionised normocalcaemia (N-iCa) (⩽1.40 mmol/l) groups, respectively. Serum FGF-23 concentrations were compared between groups and correlation analysis was performed.

RESULTS

Thirty-two cats with CKD and upper urolithiasis were included. Serum FGF-23 concentrations in the H-tCa group (median 573 pg/ml [range 125-3888]; n = 12) were significantly higher compared with the N-tCa group (median 245 pg/ml [range 94-627]; n = 20) (P = 0.001). Serum FGF-23 concentrations in the H-iCa group (median 1479 pg/ml [range 509-3888]; n = 6) increased significantly compared with the N-iCa group (median 245 pg/ml [range 94-637]; n = 26) (P <0.001). Serum FGF-23 concentrations significantly correlated with serum tCa (r = 0.511, P = 0.003) and blood iCa concentrations (r = 0.425, P = 0.015) but not serum creatinine (r = 0.279, P = 0.122) or phosphorus concentrations (r = 0.208, P = 0.253).Conclusions and relevance Increased serum FGF-23 concentrations were associated with hypercalcaemia independently of creatinine and phosphate status in cats with CKD and upper urolithiasis.

Factors Affecting the Outcome of Medical Treatment in Cats with Obstructive Ureteral Stones Treated with Tamsulosin: 70 Cases (2018-2022)

Simple Summary

Other than surgical approaches the treatment options for feline ureterolithiasis are limited compared to those of human medicine. After various studies on ureteral muscle relaxation drugs, tamsulosin has been used as a treatment for distal ureteral stones in human medicine. However, the available clinical veterinary data on the efficacy of drugs that relax the ureter are limited. Thus, this study aimed to investigate the factors affecting the outcome of tamsulosin treatment for feline ureterolithiasis. With tamsulosin treatment, the ureteric stone passage was confirmed in 22 out of 70 cats, with a success rate of 31.43%. Negative factors with statistical significance for stone passage in this study were high baseline creatinine levels, female sex, proximal location of stones, and large diameter stones. The results of this study suggest that tamsulosin can be considered for the treatment of ureterolithiasis in cats with small distal ureteral stones. In addition, this study serves as an important reference for determining whether medical treatment of feline ureteral obstruction using tamsulosin can be attempted.

Abstract

The incidence of diseases associated with feline ureteral obstruction is increasing; however, non-surgical treatment options are limited. This study evaluated the outcome of medical treatment in cats with obstructive ureteral stones treated with tamsulosin and identified potential factors predicting spontaneous stone passage. We retrospectively reviewed 70 client-owned cats treated at the Western Referral Animal Medical Center, Seoul, Korea, from 2018 to 2022. All the cats had obstructive ureterolithiasis and were treated using tamsulosin. The baseline characteristics of the cats, stone diameter and location, and stone passage outcomes were analyzed. Stone passage occurred in 22 cats; the remaining 48 cats showed no change in stone locations. Sex, creatinine, and diameter and location of stones were potential risk factors associated with successful stone passage, but age, weight, and side of the stone were not. No serious adverse events related to tamsulosin treatment were observed. This is the first study to identify the risk factors predictive of the spontaneous stone passage of cats with obstructive ureterolithiasis after tamsulosin treatment. Tamsulosin could be an alternative treatment for ureteral obstruction in male cats with smaller distal ureteral stones and low baseline serum creatinine levels. These findings could help develop guidelines for treating feline ureterolithiasis.

F, Oliveira H, Queiroz L, Borges N, Bragato N, Fioravanti M. Mineral composition and clinical aspects of urolithiasis in cats in Brazil

ABSTRACT Between October 2016 and October 2017, 63 feline uroliths were analyzed at Universidade Federal de Goiás (UFG) by using both chemical analysis and energy dispersive spectroscopy (EDS). The most frequent mineral type found was struvite (53.9%), followed by urate (39.7%), calcium oxalate (30.1%) and calcium phosphate (25.3%). Calculus containing xanthine, cystine and silica were not observed. Uroliths classified as simple, comprised a total of 34/63. Amongst the 42 animals present in the study, 26 were male and 16 were female. Pure breed animals comprised 14.4% of the total, and the breeds observed within the study were the Persian, Himalayan, Siamese, and Angora. Cats between 25-72 months old were more frequently diagnosed with uroliths. The clinical signs varied between systemic and urinary signs and the most found were anorexia, vomiting, hematuria and dysuria. All patients were either spayed or neutered and 34 patients had no outdoor access. Familial information was unknown in almost 100% of the cases. The results observed in the present study serve as a basis for future comparisons related to the epidemiology of urinary lithiasis in Brazil, especially for the feline species.

Use of tetrasodium EDTA acid for the treatment of intraluminal obstruction of subcutaneous ureteral bypass devices

OBJECTIVES

The aim of this study was to evaluate the efficacy and tolerability of a 4% tetrasodium EDTA (tEDTA) infusion protocol in the subcutaneous ureteral bypass (SUB) devices of cats with intraluminal obstruction at a veterinary teaching hospital between July 2017 and April 2020.

METHODS

This was a retrospective controlled study. Cats with an obstructed SUB device underwent a 4% tEDTA infusion protocol. Obstruction of the device was diagnosed based on renal pelvic dilation, dilatation of the ureter, mineralized material within the device (cystostomy or nephrostomy catheters) seen on ultrasound, the absence of visible bubbles within the renal pelvis and/or urinary bladder following ultrasound-guided flushing of the device with saline.

RESULTS

A total of 16 tEDTA infusion protocols were performed in 14 cats. The infusion protocol was considered successful in 11/16 SUB devices (68.8%). Six devices (n = 6/11; 54.5%) had recurrence of obstruction with a median time of 87 days. One or more episodes of self-limiting pollakiuria and/or hematuria following infusion was seen in eight patients (n = 8/14; 57.1%).

CONCLUSIONS AND RELEVANCE

Infusions of 4% tEDTA successfully relieved intraluminal obstruction in patients with occluded SUB devices; however, the recurrence of obstruction was common. Additional studies evaluating case selection and optimal protocols are warranted.

Upper urolithiasis in cats with chronic kidney disease: prevalence and investigation of serum and urinary calcium concentrations

OBJECTIVES

This study aimed to define the prevalence of upper urolithiasis in cats with chronic kidney disease (CKD) in a referral population, and to compare urinary calcium:creatinine ratio (UCa:Cr), and total and ionised calcium between cats with CKD with and without upper urolithiasis.

METHODS

The medical records of cats diagnosed with CKD were reviewed for signalment, body weight, diet and prevalence of upper urolithiasis. Cats with preserved urine samples were further classified into two groups: urolithiasis group (upper urolithiasis identified by abdominal ultrasonography) and control group (CKD of unknown origin). Serum biochemical analysis, CKD stage, blood gas analysis, urine specific gravity and UCa:Cr were compared between groups using a two-sample t-test or Mann-Whitney U-test for continuous variable and a χ2 test or Fisher's exact test for categorical variables. Multivariable binary logistic regression analysis was used to identify risk factors.

RESULTS

Among the 140 cats with CKD, the prevalence of upper urolithiasis was 73%. Fifty cats (5, 29 and 16 cats with CKD stages 1, 2 and 3, respectively) with urine samples met the inclusion criteria and were included in the analysis. Among cats with CKD, being purebred (odds ratio [OR] = 81.56; P = 0.03) and being fed dry food only (OR = 25.06; P = 0.001) were identified as independent upper urolithiasis risk factors; those with upper urolithiasis were more likely to be exclusively fed with urine-acidifying food (P <0.001) and have increased serum ionised calcium (iCa) (P = 0.044), fractional excretion of calcium (P = 0.45) and UCa:Cr (P = 0.005) than cats with CKD without upper urolithiasis.

CONCLUSIONS AND RELEVANCE

Cats with CKD that were purebred, fed dry food and fed urine-acidifying food only often had upper urolithiasis. A higher UCa:Cr may be a result of increased serum iCa and may cause upper urolithiasis.

Lower urinary tract lithiasis of cats in Algeria: Clinical and epidemiologic features

Aim

This study aims to describe the clinical symptoms, diagnosis, and treatment of urolithiasis of the lower urinary tract and to determine the main risk factors involved in the occurrence of urinary lithiasis in cats in Algeria from 2016 to 2018.

Materials and Methods

During the study period, 465 cats were examined and 32 cases of urolithiases were selected and investigated by conducting physical examinations, blood analyses, urinalysis, X-ray radiography, and ultrasonography. Parameters such as breed, age, or sex were studied and reported in a farm return to analyze risk factors involved in the formation of lower urinary urolithiasis.

Results

The most clinically relevant symptoms of urolithiasis observed in cats were dysuria, pollakiuria, hematuria, and stranguria. Urinalysis and blood analysis revealed a significant presence of urinary crystals and acute kidney failure in nine cats. The ultrasonography and radiography confirmed the diagnosis of urolithiasis with the incidence of 43.75% and 31.25%, respectively. The lower urinary tract urolithiasis appeared to be more frequent in European and Siamese cats. In addition, cats aged between 4 and 8 years old were the most affected. Male cats (87.50%) were more affected than female cats. Finally, the lower urinary tract urolithiasis was more frequent in cats consuming the commercial pet food, previously castrated, and confined inside the house.

Conclusion

Complete clinical assessments, in addition to complementary examinations, are necessary and beneficial in treating the animal and preventing possible complications. Whether the choice of therapy is surgical or treatment with drugs, it is crucial to understand that the elimination of the stone is not an end, but the beginning of a series of investigations. Because of their impact on both the formation and elimination of metabolites, it has been found that factors, such as race, gender, age, diet, and lifestyle, should be considered as potential risk factors for urolithiasis.

Quantified water intake in laboratory cats from still, free-falling and circulating water bowls, and its effects on selected urinary parameters

OBJECTIVES

The study objectives were to determine if the method of water presentation (still [S], circulating [C] or free-falling [FF] bowl systems) influences daily water consumption in cats in a controlled environment, and whether differences in water intake affect urine relative super saturation (RSS) for calcium oxalate and struvite, urine specific gravity (USG), urine osmolality (Uosmol) and urine volume.

METHODS

Sixteen healthy laboratory cats fed a dry diet were individually housed with urine collection systems. Each cat underwent a randomized 2 week crossover period with all bowl systems, allowing a 1 week acclimation period between each crossover. Water intake was measured daily by bowl weight, accounting for spillage and evaporation. USG and urine volume were measured daily, whereas other urinary parameters were measured at various time points throughout each 14 day crossover period.

RESULTS

Fourteen cats completed the study. Average daily water intake (ml/kg/day), urine volume, USG and urine RSS for struvite and calcium oxalate were not significantly different between water bowls. Uosmol was significantly higher in C compared with S and FF bowl systems (P = 0.009 for both). Three individual cats demonstrated a significant water bowl preference (Cat 4: C >S, P = 0.039; Cat 10: FF >C, P = 0.005; Cat 11: S >C, P = 0.037).

CONCLUSIONS AND RELEVANCE

Overall, water bowl type had no appreciable effect on water intake. Uosmol was the only urinary parameter found to be significantly different, and was higher for the C bowl. The implication of this is unknown, considering water intake did not differ significantly between bowls. Alternative methods to increase water intake should be implemented beyond providing unique water bowls in patients where augmented water intake would be beneficial for disease management.

Evaluation of three herbal compounds used for the management of lower urinary tract disease in healthy cats: a pilot study

OBJECTIVES

Lower urinary tract disease (LUTD) occurs commonly in cats, and idiopathic cystitis (FIC) and urolithiasis account for >80% of cases in cats <10 years of age. Although several strategies have been recommended, a common recommendation is to induce dilute urine resulting in more frequent urination and to dilute calculogenic constituents. In addition to conventional therapy using modified diets, traditional Chinese and Western herbs have been recommended, although only one - choreito - has published data available. We evaluated three commonly used herbal treatments recommended for use in cats with LUTD: San Ren Tang, Wei Ling Tang and Alisma. We hypothesized that these three Chinese herbal preparations would induce increased urine volume, decreased urine saturation for calcium oxalate and struvite, and differences in mineral and electrolyte excretions in healthy cats.

METHODS

Six healthy spayed female adult cats were evaluated in a placebo-controlled, randomized, crossover design study. Cats were randomized to one of four treatments, including placebo, San Ren Tang, Wei Ling Tang or Alisma. Treatment was for 2 weeks each with a 1 week washout period between treatments. At the end of each treatment period, a 24 h urine sample was collected using modified litter boxes.

RESULTS

Body weights were not different between treatments. No differences were found in 24 h urinary analyte excretions, urine volume, urine pH or urinary saturation for calcium oxalate or struvite between treatments.

CONCLUSIONS AND RELEVANCE

The results of this study do not support the hypothesis; however, evaluation of longer-term and different dosage studies in cats with LUTD is warranted.

Risk factors associated with feline urolithiasis

Urinary tract diseases are among the main reasons for consultation in veterinary clinics and hospitals. It affects animals of any age, breed and gender. Among the diseases that affect this system, urolithiasis is the second largest cause of clinical signs compatible with feline urinary tract disease. The term urolithiasis refers to the presence of uroliths in any region of the urinary tract, but it is more commonly seen in the bladder and urethra. Uroliths are classified based on the type of mineral present in their composition, therefore, quantitative and qualitative analyzes are important for a better therapeutic approach. The animals may suffer from the disease and be asymptomatic, or show nonspecific clinical signs, making the diagnosis difficult. The disease should not be seen as a single problem, but as a consequence of various disorders. As dietary, metabolic, genetic and infectious causes, as well as factors that potentiate the chance of development of uroliths such as breed, age, sex, age range, obesity, sedentary lifestyle, geographic region and climate. Thus, the knowledge of the factors that influence the formation of uroliths, as well as the understanding of the pathophysiology, are key elements for better alternatives of therapy and prevention. The recognition of these factors helps to identify susceptible populations, minimizing exposure and increasing the protection factors, which facilitates the diagnosis and treatment of patients with urolithiasis. The objective of this paper is to present the main risk factors involved in the formation of urinary lithiasis in felines.

Pathology and Epidemiology of Oxalate Nephrosis in Cheetahs

To investigate cases of acute oxalate nephrosis without evidence of ethylene glycol exposure, archived data and tissues from cheetahs ( Acinonyx jubatus) from North America ( n = 297), southern Africa ( n = 257), and France ( n = 40) were evaluated. Renal and gastrointestinal tract lesions were characterized in a subset of animals with ( n = 100) and without ( n = 165) oxalate crystals at death. Crystals were confirmed as calcium oxalate by Raman spectroscopy in 45 of 47 cheetahs tested. Crystals were present in cheetahs from 3.7 months to 15.9 years old. Cheetahs younger than 1.5 years were less likely to have oxalates than older cheetahs ( P = .034), but young cheetahs with oxalates had more oxalate crystals than older cheetahs ( P < .001). Cheetahs with oxalate crystals were more likely to have renal amyloidosis, interstitial nephritis, or colitis and less likely to have glomerular loop thickening or gastritis than those without oxalates. Crystal number was positively associated with renal tubular necrosis ( P ≤ .001), regeneration ( P = .015), and casts ( P ≤ .001) but inversely associated with glomerulosclerosis, renal amyloidosis, and interstitial nephritis. Crystal number was unrelated to the presence or absence of colitis and was lower in southern African than American and European animals ( P = .01). This study found no evidence that coexisting chronic renal disease (amyloidosis, interstitial nephritis, or glomerulosclerosis), veno-occlusive disease, gastritis, or enterocolitis contributed significantly to oxalate nephrosis. Oxalate-related renal disease should be considered as a potential cause of acute renal failure, especially in young captive cheetahs. The role of location, diet, stress, and genetic predisposition in the pathogenesis of oxalate nephrosis in cheetahs warrants further study.

Outcomes of ureteral surgery and ureteral stenting in cats: 117 cases (2006-2014)

OBJECTIVE

To evaluate and compare outcomes in cats following ureteral surgery or ureteral stent placement.

DESIGN

Retrospective case series.

ANIMALS

117 cats.

PROCEDURES

Data regarding signalment, history, concurrent disease, clinical signs, clinicopathologic tests, surgical procedures, and perioperative complications (including death) were recorded. Follow-up data, including presence of signs of chronic lower urinary tract disease, chronic urinary tract infection, reobstruction, and death, if applicable, were obtained by records review or telephone contact with owners. Variables of interest were compared statistically between cats treated with and without stent placement. Kaplan-Meier analysis and Cox regression were performed to assess differences in survival time between cats with and without ureteral stents.

RESULTS

Perioperative complications referable to the urinary tract were identified in 6 of 43 (14%) cats that had ≥ 1 ureteral stent placed and 2 of 74 (3%) cats that underwent ureteral surgery without stenting. Perioperative mortality rates were similar between cats with (4/43 [9%]) and without (6/74 [8%]) stents. After surgery, signs of chronic lower urinary tract disease and chronic urinary tract infection were significantly more common among cats with than cats without stents. Nineteen of 87 (22%) cats with follow-up information available had recurrent obstruction; incidence of reobstruction did not differ between cats with and without stents. Median survival time did not differ between the 2 groups.

CONCLUSIONS AND CLINICAL RELEVANCE

The potential for signs of chronic lower urinary tract disease and chronic infection, particularly among cats that receive ureteral stents, warrants appropriate client counseling. Judicious long-term follow-up for detection of reobstruction is recommended.

Current Understanding of the Pathogenesis of Progressive Chronic Kidney Disease in Cats

In cats with chronic kidney disease (CKD), the most common histopathologic finding is tubulointerstitial inflammation and fibrosis. However, these changes reflect a nonspecific response of the kidney to any inciting injury. The risk of developing CKD is likely to reflect the composite effects of genetic predisposition, aging, and environmental and individual factors that affect renal function over the course of a cat's life. However, there is still little information available to determine exactly which individual risk factors predispose a cat to develop CKD. Although many cats diagnosed with CKD have stable disease for years, some cats show overtly progressive disease.

An imaging investigation of in situ uroliths in hospitalized cats in New Zealand and in the United States

The submission rates of feline uroliths to laboratories and the composition of uroliths have been reported in studies. The prevalence of uroliths reported on imaging findings has not been published. The objective of this retrospective study was to use imaging data to investigate the anatomical location and the prevalence of macroscopic in situ uroliths in cats. Radiographs, sonograms and imaging reports from two cohorts of cats (from New Zealand (n = 497) and the United States (n = 693)) from 2004‐2013 were reviewed for the presence of in situ uroliths. Uroliths were categorized by their location in the lower or upper urinary tract. Radiographic studies were performed on 43% (212/497) of the cats from New Zealand and 50% (349/693) of the cats from the USA. Sonographic studies were performed on 57% (285/497) of the cats from New Zealand and 50% (344/693) of the cats from the USA. The total prevalence of uroliths was 3% in the New Zealand cohort and 13% in the USA cohort. Lower tract urolith prevalence in the New Zealand cohort was 2.4% (5/212) in cats ≤ 6y and 1.1% (3/285) in cats >6y. Upper tract urolith prevalence in the New Zealand cohort was 0.5% (1/212) in cats ≤ 6y and 1.8% (5/285) in cats >6y. Lower tract urolith prevalence in the United States cohort was 6.0% (11/183) in cats ≤ 6y and 2.9% (15/510) in cats >6y. Upper tract urolith prevalence in the United States cohort was 2.7% (5/183) in cats ≤ 6y and 10.2% (52/510) in cats >6y. The prevalence of uroliths in the upper tract or lower tract was low in the New Zealand cohort compared to that of cats in the USA cohort, irrespective of age category. Geographical location may be important when evaluating risk factors for feline urolithiasis.

Percutaneous ureteral stent placement for the treatment of a benign ureteral obstruction in a Sumatran tiger (Panthera tigris sumatrae)

A 15-year-old, 113 kg intact male Sumatran tiger (Panthera tigris sumatrae) was evaluated for weight loss, polydipsia, and intermittent hematuria. The tiger was immobilized for diagnostic testing including blood work, urinalysis, and abdominal ultrasound. Laboratory testing demonstrated macro- and microhematuria, azotemia, and an increased urine protein:creatinine ratio. Abdominal ultrasound revealed bilateral ureterolithiasis as well as hydronephrosis and ureteral dilation. Ultrasonography performed 5 months later revealed worsening of the right-sided hydronephrosis and hydroureter and a decrease in the severity of dilation on the left side presumably from passage of the left-sided ureteral calculi. Nephroureteral decompression via the placement of a stent was elected. A pigtail ureteral catheter (8.2 French diameter) was placed in the right ureter via an antegrade percutaneous approach utilizing ultrasound and fluoroscopic-guidance. Following stent placement, macrohematuria resolved although microhematuria was noted in opportunistic urine samples. Five months after stent placement, the azotemia had mildly progressed, the urine protein:creatinine ratio was improved, the right hydronephrosis and hydroureter had completely resolved, and the ureteral stent remained in the appropriate position. The tiger had clinically improved with a substantial increase in appetite, weight, and activity level. Ureteral stenting allowed for nephroureteral decompression in the captive large felid of this report, and no complications were encountered. Ureteral stenting provided a minimally invasive method of managing ureteral obstruction in this patient and could be considered in future cases due to the clinical improvement and low morbidity.

Estudo da ocorrência de litíase renal e ureteral em gatos com doença renal crônica

Investigou-se a ocorrência de nefrolitíase e/ou ureterolitíase em 72 gatos portadores de doença renal crônica (DRC), classificados predominantemente no estágio II, segundo os critérios designados pela IRIS - International Renal Interest Society. Destes pacientes, 47 (65,27%) apresentaram litíase renal e ou ureteral. Não houve diferença estatística entre o grupo de estudo (DRC com cálculo) e o grupo controle (DRC sem cálculo) em relação à idade (p=0,274). Apesar disso, os pacientes portadores de nefrolitíase e/ou ureterolitíase apresentaram maiores indícios de lesão renal, caracterizados por diferenças estatisticamente relevantes da densidade urinária (p=0,013) e pelo menor tamanho dos rins direito (p=0,009) e esquerdo (p=0,048). Encontrou-se similaridade entre os grupos em relação a outros parâmetros, tais como as concentrações plasmáticas de cálcio total, cálcio ionizado, fósforo, sódio, potássio e paratormônio intacto (PTHi). Os valores das concentrações séricas de ureia e bicarbonato diferiram entre os grupos, com valores de p=0,039 e p=0,037, respectivamente. Além disso, foi mensurada a pressão arterial, que se manteve inalterada na comparação entre o grupo de estudo e o grupo controle. Os resultados obtidos reforçam a necessidade de acompanhamento ultrassonográfico de todos os pacientes portadores de DRC, mesmo daqueles assintomáticos ou em estágios iniciais da doença.

Indwelling double pigtail ureteral stent combined or not with surgery for feline ureterolithiasis: complications and outcome in 15 cases

Ureteral obstruction secondary to ureterolithiasis in cats is a challenging situation. Ureteral stenting has recently been introduced to prevent complications that often occurred after ureterotomy or other invasive surgeries. The purpose of this study is to describe the stenting technique and perioperative difficulties, as well as long-term outcome and complications with ureteral stenting in 12 cats with ureteroliths. Fifteen 2.5 Fr soft double pigtail multi-fenestrated ureteral stents were placed in an anterograde fashion under open surgical approaches and with fluoroscopic guidance in 12 cats. Nine cats received a unilateral stent and three received bilateral stents. Ureterotomy or ureteral resection and end-to-end anastomosis were performed in three and four cases, respectively. In six cats, papillotomy was performed to facilitate dilatator and stent placement. All cats recovered well from the surgical procedure, except one cat, which died during the anaesthesia recovery period. Postoperative complications included dysuria (three cases, diagnosed at 15 days, 1 month and 3 months, respectively), urinary tract infection (one case, 1 month after surgery), stent migration requiring stent replacement (one case, 19 months after surgery) and stent obstruction requiring stent removal (three cases with previously end-to-end anastomosis between 2 and 8 months after surgery). Nine cats (75%) were alive at a mean follow-up of 453 ± 194 (123–720) days. The median survival time was >415 days. Stent placement appeared to be a valuable and safe option for treating ureteral obstruction in cats. However, periodic and long-term monitoring of stents is warranted.