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Percutaneous cystolithotomy (PCCL) is a minimally-invasive technique for removal of cystoliths. There is currently no information regarding optimum patient positioning during PCCL. The objective of this study was to assess whether patient positioning affected ease of cystolith retrieval via PCCL. PCCL was performed to retrieve artificial "cystoliths" in three canine cadavers weighing between 15 and 35 kg, using a threaded cannula and a rigid 30° 2.7 mm cystoscope. "Cystolith" retrieval was performed by retrograde flushing and use of a flexible stone basket, with the dog in 10° Trendelenburg, 10° reverse Trendelenburg, or neutral position. The location of the "cystoliths", number retrieved during flushing, and total time for retrieval were recorded and compared between different positions. The mean total time for "cystolith" retrieval was 392 ± 131 s, with 162 ± 20 s for flushing and 221 ± 123 s for basket-retrieval. The mean number of "cystoliths" retrieved during flushing was 3 ± 2. No significant differences were detected when comparing retrieval times between different positions. The predominant location of the "cystoliths" within the bladder varied depending on the position of the dog. In neutral, 93 % were located adjacent to the ureteric openings, whereas in 10° reverse Trendelenburg, 100 % were located by the urethral orifice. In 10° Trendelenburg, 60 % "cystoliths" were located at the tip of the cannula. Cystolith retrieval during PCCL can be performed in either neutral, Trendelenburg or reverse Trendelenburg position. Changing the dog's position may be useful in cases where cystolith retrieval is challenging, to move the cystoliths and enable different techniques to be employed using the stone basket., Competing Interests: Conflict of Interest None of the authors has any financial or personal relationships that could inappropriately influence or bias the content of the paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Urocystolithiasis is a common problem in dogs; many canine uroliths are resistant to medical dissolution. Novel management options would expand, and in some cases improve, current urolith retrieval strategies., Hypothesis/objectives: To describe a previously unreported technique by the Ellik bladder evacuator (EE) to assist in minimally invasive, cystoscopic retrieval of canine cystoliths., Animals: Twelve client-owned dogs presented with urocystolithiasis., Methods: In this retrospective study, dog demographics, procedure type and duration, and clinical outcomes of dogs undergoing cystoscopic cystolith retrieval utilizing the EE are described., Results: Twelve dogs underwent 13 cystoscopic procedures utilizing EE for cystolith retrieval. The EE was used in accordance with previously described techniques via a custom-made adaptor. Ten dogs were spayed females; 8 different breeds were represented. In 8 of 13 procedures, transurethral cystoscopy alone by EE with or without wire basket or grasping forceps was performed with a median procedure duration of 36 minutes (range, 16-52). In the other 5 procedures, additional interventions (ie, laser lithotripsy, percutaneous perineal approach, urethral stricture ballooning, ethanol parathyroid ablation) were performed as indicated with a median procedure duration 110 minutes (range, 42-144). No complications were noted in association with the use of the EE; retrieval of cystoliths was complete in 12 of 13 procedures., Conclusions and Clinical Importance: Use of the EE during cystoscopy might aid in minimally-invasive retrieval of cystoliths. This work provides a starting point for additional discussion regarding its benefit relative to current interventions., (© 2024 The Author(s). Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Objective: To investigate the frequency at which cystine and urate cystoliths (stones) are visible on radiographs prior to surgical or nonsurgical retrieval., Methods: Records of client-owned dogs (n = 331) were analyzed between January 2019 and December 2023 for cystoliths submitted for stone analysis after surgical removal or nonsurgical retrieval. Records were analyzed for cystolith type; when cystine or urate stones were identified, records were analyzed for signalment, procedure, presence of mineral opaque cystoliths on pre-procedural radiographs, urine pH and crystalluria, history of previous cystoliths, prior prescription diet attempt, recurrence, and genetic, congenital and acquired comorbidities. Descriptive statistics were generated after data collection., Results: 31 of 331 (9%) were cystine stones, 49 of 331 (15%) were urate, and 1 of 331 (0.3%) was a mix of urate and cystine. When radiographs were taken prior to stone removal, 24 of 28 (85%) of urate, 24 of 26 (92%) of cystine, and 1 of 1 (100%) of urate/cystine were visible on radiographs., Conclusions: Cystine and urate stones are visible on survey radiography at a high frequency in dogs., Clinical Relevance: While cystine and urate stones have been historically designated as radiolucent, they are frequently radiopaque on radiographs. Radiopacity is commonly used as one of the criterion to determine whether a dissolution or prevention diet is an appropriate management technique, particularly when determination of the stone type has yet to be performed. As a result, these findings may prompt clinicians to investigate other patient-specific factors before a specific dietary recommendation is made.

This retrospective case series describes the use of progressive urethral dilation in 22 client-owned male horses undergoing perineal urethrotomy (PU) for cystolith removal. Medical records of horses undergoing PU and urethral dilation for treatment of cystolithiasis were reviewed. Dilation of the pelvic urethra was performed following PU and using customized dilators with the same length (30cm) and with various outer diameters (25 to 45mm). Analyzed data included: signalment, cystolith size, renal ultrasound findings, method used for cystolith removal, diameter of urethral dilators, intra- and post-operative complications, and hospitalization time. Cystolith size ranged between 37mm and 90mm. Dilation of the pelvic urethra was as follows: 35mm (n=8), 25mm (n=6), 39mm (n=3), 33mm (n=2), 28mm (n=2) and 45mm (n=1). In 6 cases, the cystolith was removed without fragmentation. In the remaining 16 horses, lithotripsy was performed with forceps (n=9) or a pneumatic scaler (n=7). In 15 horses a retrieval device was used to aid in calculi removal. Hospitalization time ranged between 1 and 5 days. Intra-operative complications occurred in one horse. No post-operative complications were recorded. Follow-up information was available for 21 horses (range 1-8 years). Urethral dilation via PU may be a viable option for cystolith removal in male horses., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest related to this report., (Copyright © 2023. Published by Elsevier Inc.)

Background: Pseudomembranous cystitis (PMC) in cats is a recognized disease, but concurrent mineralization is reported rarely and its outcome is poorly described., Hypothesis and Objectives: Describe a population of cats with PMC and the prevalence of concurrent mineralization., Animals: Twenty-six cats with PMC., Methods: Medical records were retrospectively reviewed (January 2016 to December 2021). Cats with an ultrasound diagnosis of PMC were included. Clinicopathologic results, imaging, treatment, and outcome were reviewed., Results: All cats were male and 21 (80%) were diagnosed with urethral obstruction (UO). Five cats (23.8%) had positive urine culture (Staphylococcus felis, 3/5; Proteus mirabilis, 2/5) with a median urine pH of 8 (range, 6-9). All cats had ultrasonographic changes suggestive of mineralization. On ultrasound examination, 10 cats (38.5%) had pseudomembranes with acoustic shadowing suggestive of mineralization, 15 (57.7%) had changes indicative of ulceration, and 8 (31%) had changes compatible with of a urachal anomaly. Twenty-two cats received medical treatment, 4 underwent surgery (3 percutaneous cystolithotomy, 1 cystotomy). Twenty cats (77%) survived to discharge. Follow-up ultrasound examination indicated resolution of PMC in 6/7 cats, 4 had persistent hyperechoic bladder lining. Five of 12 cats with follow-up had a relapse of lower urinary tract signs., Conclusions and Clinical Importance: Pseudomembranous cystitis was diagnosed mainly in male cats with UO and imaging findings suggestive of mineralization were present in all cases. Frequent negative urine culture suggests a different etiology than encrusting cystitis related to urease-positive bacteria. Good outcomes can be achieved with medical management., (© 2023 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC. on behalf of the American College of Veterinary Internal Medicine.)

Objective: Compare percutaneous cystolithotomy (PCCL) and open cystotomy (OC) for removal of bladder and urethral uroliths., Design: Retrospective study., Animals: Client-owned dogs and cats that underwent PCCL (n = 41) or OC (n = 40) between January 1, 2014 and February 28, 2018 at a referral center., Methods: Medical records of dogs and cats that underwent a PCCL or an OC were reviewed. History, signalment, physical examination, diagnostic tests, length of the procedure and anesthesia, complications, and duration of hospitalization were recorded., Results: A total 17 cats (PCCL = 10; OC = 7) and 64 dogs (PCCL = 31; OC = 33) were included. There was no significant difference, regardless of species, in the mean surgical time (45 min [24-160 min] and 48.5 min [15-122 min] with P = .54 in dogs, P = .65 in cats) nor mean duration of anesthesia (90 min [50-120 min] and 98 min [54-223 min] with P = .87 in dogs, P = .08 in cats) in the PCCL and OC groups respectively. Number of uroliths did not affect duration of surgery in either group. Complete urolith removal was achieved in 98% of dogs and cats in both groups. The median hospitalization time was significantly shorter in the PCCL group for dogs (11.3 hours [range 4 to 51.3] in the PCCL vs 56.6 hours [range 7.3 to 96] in the OC group; P < .001) but did not differ for cats (24.5 hours [range 8.3 to 30] in the PCCL vs 56.6 hours [range 10.1 to 193.2] in the OC group; P = .08)., Conclusion and Clinical Relevance: Bladder urolith removal by PCCL procedure is no longer than OC. Further studies are needed to compare the pain related to procedure between PCCL and OC., (© 2022 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Urolithiasis is the most common cause of urinary tract disease in small ruminants and has significant economic and production impacts worldwide. Urolithiasis is multifactorial in origin and generally begins with the formation of cystoliths followed by urethral obstruction. The condition is most common in males. Clinical signs are variable depending on the severity of the obstruction. Uroliths can be calcium, struvite, or silicate based; however, struvite and amorphous magnesium calcium phosphate are the most common urolith types observed in small ruminants. Although urethral process (vermiform appendage) amputation is widely considered the first line of treatment, reobstruction is common within the first 36 hours. Surgical interventions such as temporary tube cystostomy, perineal urethrostomy (PU), modified proximal perineal urethrostomy, vesico-preputial anastomosis (VPA), and urinary bladder marsupialization (BM) are reported to carry an improved prognosis for long-term survival. PU carries a lower proportion of long-term success (> 12-month survival time) when compared with VPA and BM. Stoma stricture and urine scald are the most commonly observed surgical complications. Currently, the literature provides minimal direction for clinician decision-making in managing these cases while accounting for patient history, client financial ability, composition of calculi, and potential treatment complications. Small ruminant urinary obstructions are challenging and complicated conditions to treat, due to their multifactorial etiology, ruminant urogenital anatomy, and the variety of imperfect treatment options available. The purpose of this article this article is to provide veterinary practitioners with decision trees to guide management and treatment of urolithiasis in small ruminants.

Case Description: An 8-year-old spayed female Yorkshire Terrier-Poodle dog was evaluated for persistent pollakiuria and stranguria following routine cystotomy for calcium oxalate cystoliths., Clinical Findings: The dog presented for a cystotomy with intermittent hematuria. Postoperative radiographs revealed no remaining cystoliths. Urine, cystolith, and bladder mucosal aerobic cultures were negative. Pollakiuria, stranguria, and hematuria developed immediately after surgery and persisted despite antibiotics. Ultrasound revealed suspected fibrous adhesions within the urinary bladder lumen connecting the dorsal and ventral bladder wall creating a septum. This was confirmed cystoscopically 4 weeks after surgery., Treatment and Outcome: Cystoscopic-guided laser ablation was performed to incise abnormal tissue connecting the ventral and dorsal bladder wall using a holmium:yttrium-aluminum-garnet laser. Three weeks later, ultrasound revealed adhesion resolution though mild pollakiuria and stranguria persisted. Oxybutynin was prescribed and clinical signs resolved. At 27 months after ablation, hematuria occurred with recurrent cystoliths. These cystoliths were removed by percutaneous cystolithotomy, documenting a cystoscopically normal bladder wall. The patient had normal urination for 55.5 months after ablation, with normal bladder wall thickness on ultrasound repeated at 27 and 36 months after ablation., Clinical Relevance: To the authors' knowledge, an adhesion creating a septum between the dorsal and ventral bladder wall has not been previously reported as a complication after cystotomy in any species and should be considered as a cause of persistent lower urinary signs after surgery. Ultrasound identified the lesion in this dog. Because bladder abnormalities can develop quickly after surgery, ultrasound might be considered if urine testing is not supportive of infection. Cystoscopic-guided laser ablation was a successful minimally invasive treatment in this case.

Background: Medical dissolution of struvite uroliths in dogs is commonly recommended, but data on success rates and complications are limited., Objectives: To evaluate the efficacy of medical dissolution for suspected struvite cystoliths in dogs., Animals: Fifty client-owned dogs fed a therapeutic dissolution diet, with or without administration of antimicrobials, for treatment of suspected struvite cystoliths., Methods: Single institution, retrospective case series. Medical records were reviewed for dogs with at least 1 follow-up visit. Dissolution success, complications, and possible predictors of success were evaluated., Results: Full dissolution of cystoliths was achieved in 58% (29/50) of dogs within a median of 35 days (range, 13-167). Of 21 dogs without success, 7 each had partial dissolution, no dissolution, or undetermined outcome. Uroliths containing >10% nonstruvite mineral were common in the nonsuccess group (11/16 analyzed). Maximum urolith diameter, number of uroliths, and baseline urine pH did not differ significantly between dogs with and without success. Dissolution was more likely in dogs receiving antimicrobial therapy (OR = 16.3, 95% confidence interval 1.9-787.4, P = .002). Adverse events occurred in 9 dogs (18%); urethral obstructions were the most common, but 3 of 4 dogs with this complication were obstructed on presentation, before trial initiation., Conclusions and Clinical Importance: Results support a medical dissolution trial for dogs with suspected struvite cystoliths. If no reduction in urolith size or number occurs by 1 month, a nonstruvite composition is likely, and alternative interventions should be considered. Dogs presenting with urethral obstructions should not be considered candidates for medical dissolution., (© 2021 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC. on behalf of the American College of Veterinary Internal Medicine.)

Objectives: The aim of the study was to determine the efficacy of the low struvite relative supersaturation diet in dissolution of feline struvite cystoliths., Methods: This was a prospective, open-label, two-center study. Twelve client-owned cats were enrolled based on the radiographic appearance of their uroliths and urinalysis parameters. Cats were fed the test diet exclusively for up to 56 days. Cats were radiographed every other week until radiographic evidence of dissolution occurred or the end of the study period was reached. Cats with radiographically apparent uroliths at the end of the study period underwent cystotomy for stone retrieval and analysis., Results: Nine of the 12 cats completed the study. Eight experienced radiographic dissolution; seven of these had complete dissolution within the first month of treatment. One cat, whose owner declined cystotomy after partial dissolution at day 56, had complete radiographic resolution at 70 days of treatment. Two calcium oxalate urolith cores were removed from a cat that had partial radiographic dissolution., Conclusions and Relevance: The test diet was successful in dissolving suspected struvite cystoliths. As this diet is suitable for maintenance feeding of adult cats, it may be a suitable choice for long-term prevention of feline struvite urolithiasis.

Two mares, aged 15 and 21 years, were examined because of urinary incontinence, intermittent hematuria, and urine scalding. On admission of both horses, physical parameters were within normal limits and urine scalding of the skin at the ventral perineum was noted. Transrectal palpation and cystoscopy revealed a large type I cystolith (>10 cm) with associated hyperemia and focal ulceration of the bladder mucosa. In horse 1, hemogram, serum biochemical analysis, and renal ultrasound were not performed because of owner finances. In horse 2, results from hematological and serum biochemical analysis were unremarkable and renal ultrasonography did not reveal any abnormalities. Pneumatic impact lithotripsy in a laparoscopic retrieval pouch was performed under cystoscopic guidance after caudal epidural anesthesia, with the horses standing and under sedation. A laparoscopic retrieval device was passed alongside a flexible endoscope into the urinary bladder and the cystolith was manipulated into the pouch. A customized single stainless-steel rod scaler attached to an air compressor was used for fragmentation of the cystolith contained within the retrieval pouch. Lithotripsy time was 42 minutes for horse 1 and 31 minutes for horse 2. Both horses were released from hospital the day of surgery. Both horses were continent and voided normal streams of urine for the duration of the follow-up periods of 27 and 19 months for horse 1 and horse 2, respectively. Pneumatic impact lithotripsy in a laparoscopic retrieval pouch provided a time-efficient and minimally invasive surgical treatment option for removal of large cystoliths in mares., (Copyright © 2020 Elsevier Inc. All rights reserved.)

This retrospective case series describes the radiographic features of suspected suture-associated cystic calculi in six dogs with a history of at least one or multiple prior cystotomies. One of the dogs presented twice. Suspected suture-associated cystic calculi were multifocal, short, predominantly linear mineral opacities localized in the center of the urinary bladder on abdominal radiographs. One patient (n = 1) presented with multifocal round, pin point, and linear radiopaque calculi. The calculi were all calcium oxalate in composition. On gross examination, the calculi had a hollow center. Six cystotomies used monofilament absorbable suture material (polydioxanone [n = 4] or poliglecaprone 25 [n = 1]) in prior cystotomies. Suture material in two of the cases was unknown. Suspected suture-associated cystic calculi are a rare occurrence in veterinary medicine but should be considered in dogs that have a history of prior cystotomy, hollow core on gross analysis, and radiographic evidence of mineral opaque, predominantly linear, cystic calculi., (© 2020 American College of Veterinary Radiology.)

Uroliths are uncommon findings in rats. This report describes a case of a neutered male rat with dysuria due to an infectious cystitis as well as an urolith of the urinary bladder consisting of struvite and whewellit. Following cystotomy as well as treatment with antibiotics and analgetics the rat recovered rapidly., Competing Interests: Die Autorinnen bestätigen, dass kein Interessenkonflikt besteht., (© Georg Thieme Verlag KG Stuttgart · New York.)

Objective: To describe the use and outcome of percutaneous cystolithotomy (PCCL) for removal of urethral and bladder stones in dogs and cats., Study Design: Retrospective case series., Animals: Sixty-eight client-owned dogs and cats., Methods: Records were reviewed and analyzed for dogs and cats that underwent PCCL between January 2012 and December 2017. Signalment, clinical presentation, laboratory and imaging data, procedure time, use of lithotripsy, biopsy, perioperative and immediate postoperative complications, hospitalization times, stone composition, and urine culture results were recorded. Owners were contacted by phone or email 3 weeks after the procedure. Follow-up communications with the owner and referring veterinarian were also recorded., Results: Seventy percutaneous cystolithotomies were performed in 59 dogs and nine cats. The median duration of the procedure was 95 minutes (45-420), and lithotripsy was required in 3% (2/70) of PCCL. Complications during the procedure were reported in one case. In eighty-three percent of procedures (58/70), animals were discharged within 24 hours postoperative. Twenty-four percent (16/68) of animals had minor complications (lower urinary tract signs), and one dog had a major complication (surgical wound dehiscence) during the 3 weeks after the operation. Long-term follow-up revealed stone recurrence in 21% of cases followed more than a year after the procedure (7/33)., Conclusion: Percutaneous cystolithotomy allowed removal of bladder and urethral stones with rapid postoperative recovery and few major perioperative or short-term postoperative complications., Clinical Significance: Percutaneous cystolithotomy provides an attractive minimally invasive surgical alternative for removal of lower urinary tract stones in small animals., (© 2020 The American College of Veterinary Surgeons.)

Background: Struvite urolithiasis with bacterial urinary tract infection (UTI) is commonly reported in dogs; few data exist to describe successful dissolution protocols in dogs with naturally occurring disease. We hypothesized that a dry therapeutic urinary diet combined with targeted antimicrobial therapy can effectively dissolve presumptive struvite cystolithiasis in dogs with naturally occurring urease-producing bacterial UTI., Results: Ten dogs with presumed infection-induced struvite cystolithiasis based on lower urinary tract signs (LUTS), radiodense cystoliths, and urease-producing bacterial UTI were enrolled. At enrollment, antimicrobials and dry therapeutic urinary diet were dispensed. In addition to lack of radiographic resolution of urolithiasis, dogs with persistent clinical signs were considered non-responders. There was no significant difference in pH between responders and non-responders; USG was significantly higher in the responder group. Recheck visits continued until radiographic dissolution or failure was documented. Five of the 10 dogs achieved radiographic dissolution of cystolithiasis within a median of 31 days (range 19-103). In the other 5 dogs, surgical urolith removal was necessary due to persistent LUTS (3 dogs within 2 weeks) or lack of continued dissolution noted radiographically (1 dog with numerous cystoliths failed at day 91; 1 dog failed by day 57 with questionable owner compliance)., Conclusions: Dissolution of urinary tract infection induced struvite cystoliths can be accomplished in some dogs fed this dry therapeutic urinary diet in conjunction with antimicrobial therapy. Case selection could increase the likelihood of successful dissolution; however, if calcium phosphate is present, this could also prevent stone dissolution. If clinical signs persist despite diet and antimicrobials, stone removal is advised.

Background: T-zone lymphoma (TZL), an indolent disease in older dogs, comprises approximately 12% of lymphomas in dogs. TZL cells exhibit an activated phenotype, indicating the disease may be antigen-driven. Prior research found that asymptomatic aged Golden Retrievers (GLDRs) commonly have populations of T-zone-like cells (phenotypically identical to TZL) of undetermined significance (TZUS)., Objective: To evaluate associations of inflammatory conditions, TZL and TZUS, using a case-control study of GLDRs., Animals: TZL cases (n = 140), flow cytometrically diagnosed, were identified through Colorado State University's Clinical Immunology Laboratory. Non-TZL dogs, recruited through either a database of owners interested in research participation or the submitting clinics of TZL cases, were subsequently flow cytometrically classified as TZUS (n = 221) or control (n = 147)., Methods: Health history, signalment, environmental, and lifestyle factors were obtained from owner-completed questionnaires. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated using multivariable logistic regression, obtaining separate estimates for TZL and TZUS (versus controls)., Results: Hypothyroidism (OR, 0.3; 95% CI, 0.1-0.7), omega-3 supplementation (OR, 0.3; 95% CI, 0.1-0.6), and mange (OR, 5.5; 95% CI, 1.4-21.1) were significantly associated with TZL. Gastrointestinal disease (OR, 2.4; 95% CI, 0.98-5.8) had nonsignificantly increased TZL odds. Two shared associations for TZL and TZUS were identified: bladder infection or calculi (TZL OR, 3.5; 95% CI, 0.96-12.7; TZUS OR, 5.1; 95% CI, 1.9-13.7) and eye disease (TZL OR, 2.3; 95% CI, 0.97-5.2; TZUS OR, 1.9; 95% CI, 0.99-3.8)., Conclusions and Clinical Importance: These findings may elucidate pathways involved in TZUS risk and progression from TZUS to TZL. Further investigation into the protective association of omega-3 supplements is warranted., (© 2019 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)

Case Report: The present case series describes the clinical course and outcome of three cats diagnosed with pseudomembranous cystitis. This is an uncommon presentation of lower urinary tract obstruction but can be easily be identified by ultrasonography, revealing severe bladder wall thickening and thin hyperechoic luminal strips. The condition can be secondary to severe bacterial urinary tract infection. All cats were successfully treated with medical management only, mainly based on antimicrobials and individualised supportive therapy., Conclusion: Further evaluation of this condition is necessary in order to determine potential underlying aetiologies, pathophysiological mechanisms and the most appropriate standardised treatment., (© 2017 Australian Veterinary Association.)

The objective of this study was to determine the efficacy of feeding the commercially available diet, Purina Pro Plan Veterinary Diets UR Urinary St/Ox, for the dissolution of struvite cystoliths in cats with naturally occurring disease. Twelve cats with clinical signs of lower urinary tract disease and cystoliths confirmed via radiographs were enrolled. The cats were fed the study diet ad libitum and assessed by abdominal radiographs weekly. Cats with cystoliths that resolved based on radiographs and confirmatory ultrasound examination were considered diet successes. Cats with no change in cystolith size after 2-6 weeks underwent cystotomy for stone removal, aerobic culture and antimicrobial susceptibility testing, and analysis. All cats accepted the study diet, and weight loss was not noted over the course of the study. Total cystolith dissolution was achieved by week 2 for 5 cats, which were presumed to have struvite cystoliths. All other cats underwent cystotomy for stone removal after radiographic evidence of cystoliths were still present at 2 weeks (1 cat with severe signs), 4 weeks (5 cats), or 6 weeks (1 cat). The cystoliths that were surgically removed were calcium oxalate (5 cats) and mixed (2 cats) and would not be expected to dissolve with this diet. Follow-up radiographs from 6 cats fed the diet long term (3 presumed struvite and 3 with other cystoliths removed surgically) were collected from 1 to 6 months after beginning the study and showed no evidence of cystolith recurrence. While larger case numbers are needed, these results suggest that feeding Purina Pro Plan Veterinary Diets UR Urinary St/Ox can successfully dissolve cystoliths that are likely struvite and may lessen the risk of recurrence of struvite and calcium oxalate cystoliths., (Copyright © 2017 Elsevier Inc. All rights reserved.)

OBJECTIVE To evaluate the use of a laparoscopic specimen retrieval pouch for removal of intact or fragmented cystic calculi from standing horses. DESIGN Retrospective case series. ANIMALS 8 horses (5 geldings and 3 mares) with cystic calculi. PROCEDURES Physical examination and cystoscopic, ultrasonographic, and hematologic evaluations of urinary tract function were performed for each horse. A diagnosis of cystic calculus was made on the basis of results of cystoscopy and ultrasonography. Concurrent urolithiasis or other urinary tract abnormalities identified during preoperative evaluation were recorded. Horses were sedated and placed in standing stocks, and the perineum was aseptically prepared. Direct access to the urinary bladder was gained in geldings via perineal urethrotomy or in mares by a transurethral approach. Calculi were visualized endoscopically, manipulated into the retrieval pouch, and removed intact or fragmented (for larger calculi). RESULTS For 4 geldings and 1 mare, fragmentation was necessary to facilitate calculus removal. Mean duration of surgery was 125 minutes, and trauma to the urinary bladder and urethra was limited to areas of hyperemia and submucosal petechiation. No postoperative complications were encountered for any horse. When lithotripsy was required, the retrieval pouch provided an effective means of stabilizing calculi and containing the fragments for removal. CONCLUSIONS AND CLINICAL RELEVANCE Use of the laparoscopic specimen retrieval pouch was an effective, minimally traumatic method for retrieving cystic calculi from standing horses. The pouch protected the urinary bladder and urethra from trauma during calculus removal and allowed for stabilization, containment, and fragmentation of calculi when necessary.

This study reports emerging trends in feline urolithiasis in Canada during the past 16.8 y, evaluates associations of breed and gender with urolith types, and reports on feline submissions from outside of Canada. Struvite and calcium oxalate uroliths comprised > 90% of all uroliths submitted. In cats, oxalate submissions outnumbered struvite submissions from Canada, Hong Kong, Denmark, and the United Arab Emirates, while Australian struvite submissions outnumbered calcium oxalate submissions. In Canada, the majority of urolith submissions were from domestic cats followed by Himalayan, Persian, and Siamese cats. Males were more likely to form calcium oxalate uroliths and females were more likely to develop struvite uroliths. Compared to domestic short-haired cats, Tonkinese, Burmese, Devon rex, Himalayan, Persian, and Siamese cats were significantly associated with calcium oxalate urolith submission. Egyptian mau, Birman, ocicat, and Siamese breeds were over-represented amongst urate submissions.

Urinary diseases are commonly found in guinea pigs. Diagnostic workup includes clinical examination, blood testing, imaging studies, urine culture, and urinalysis. This article describes the use of transurethral cystoscopy in female guinea pigs as an ancillary tool to diagnose abnormalities within the bladder and urethra. In addition, the transurethral cystoscopic removal of uroliths measuring up to 5 mm and situated within the urinary bladder is described., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Objectives: To evaluate the influence of two feline calculolytic diets on selected parameters of mineral metabolism., Materials and Methods: Two dry commercial diets designed for struvite urolith dissolution were evaluated in 14 cats. The study was designed as a two-sequence, four-period crossover protocol with a baseline period, two 60-day "run-in" periods in which calculolytic diets (Diet 1 and Diet 2) were fed and one 30-day "wash-out" period. Data are expressed as median (range)., Results: Feeding the calculolytic diets for two months did not alter plasma concentrations of calcium, phosphorus, magnesium and parathyroid hormone. A significant (P < 0.05 in each case) decline in calcitriol was observed after administering both diets from 236.4 (122.4-429.6) to 170.4 (108.0-394.3) pmol/L (Diet 1) and from 278.4 (153.6-492.0) to 177.1 (87.6-392.4) pmol/L (Diet 2). Cats fed Diet 1 showed a significant increase in urine calcium concentration (from 0.3 (0.2-0.5) to 0.4 (0.3-0.7) mmol/L). Magnesium concentration in urine was significantly increased with both diets, from 1.4 (0.1-1.7) to 1.5 (1.3-2.4) mmol/L (Diet 1) and from 1.1 (0.4-1.9) to 2.0 (0.1-3.1) mmol/L (Diet 2)., Clinical Significance: Both diets resulted in an increased urinary concentration of magnesium, through different mechanisms: urine acidification (Diet 1) and increased sodium load (Diet 2)., (© 2015 British Small Animal Veterinary Association.)

Urethral obstruction is a life-threatening form of feline lower urinary tract disease. Ultrasonographic risk factors for reobstruction have not been previously reported. Purposes of this retrospective cross-sectional study were to describe urinary tract ultrasound findings in cats following acute urethral obstruction and determine whether ultrasound findings were associated with reobstruction. Inclusion criteria were a physical examination and history consistent with urethral obstruction, an abdominal ultrasound including a full evaluation of the urinary system within 24 h of hospitalization, and no cystocentesis prior to ultrasound examination. Medical records for included cats were reviewed and presence of azotemia, hyperkalemia, positive urine culture, and duration of hospitalization were recorded. For medically treated cats with available outcome data, presence of reobstruction was also recorded. Ultrasound images were reviewed and urinary tract characteristics were recorded. A total of 87 cats met inclusion criteria. Common ultrasound findings for the bladder included echogenic urine sediment, bladder wall thickening, pericystic effusion, hyperechoic pericystic fat, and increased urinary echoes; and for the kidneys/ureters included pyelectasia, renomegaly, perirenal effusion, hyperechoic perirenal fat, and ureteral dilation. Six-month postdischarge outcomes were available for 61 medically treated cats and 21 of these cats had reobstruction. No findings were associated with an increased risk of reobstruction. Ultrasonographic perirenal effusion was associated with severe hyperkalemia (P = 0.009, relative risk 5.75, 95% confidence interval [1.54-21.51]). Findings supported the use of ultrasound as an adjunct for treatment planning in cats presented with urethral obstruction but not as a method for predicting risk of reobstruction., (© 2015 American College of Veterinary Radiology.)

Case Description: An 11-year-old Arabian gelding was evaluated for hematuria, stranguria, and pollakiuria that had been observed for 1 week., Clinical Findings: Transrectal palpation revealed a 5-cm firm round mass in the urinary bladder. Cystoscopy and transrectal ultrasonography confirmed the diagnosis of urinary bladder urolithiasis., Treatment and Outcome: A multiportal transparalumbar fossa laparoscopic approach was selected for cystotomy and urolith removal. Cystotomy and urolith removal was performed with sedation and local anesthesia with the horse standing. No perioperative complications were observed. Urination returned to normal 5 days after surgery. The horse returned to its previous level of activity at 3 weeks after surgery., Clinical Relevance: Findings suggested that minimally invasive transparalumbar fossa laparoscopic approach can be successfully used for cystotomy and urolith extraction in standing horses; this avoids the disadvantages of conventional laparocystotomy for removal of large uroliths in male equids and the potential complications of general anesthesia and recovery. The technique provided excellent viewing and access to the bladder, permitting extraction of the urolith and secure closure of the cystotomy with minimal tension and tissue trauma to the bladder.

Retrograde ejaculation (RE) has been reported in humans and animals but RE with subsequent sperm calculi has rarely been reported. This report documents clinical and pathological findings of spontaneous sperm cystolithiasis in four rhesus macaques. While this condition has been associated with repeated electroejaculation, spontaneous sperm cystolithiasis is highly unusual. The animals presented with either stranguria, dysuria, hematuria, distended abdomen or lethargy. Ultrasound examination revealed several hyperechoic masses within the lumen of the urinary bladder. The animals were euthanized due to poor prognosis or study end points. Postmortem examination revealed multiple angular, amorphous, soft to firm, pale yellow to greenish-brown and variably sized calculi in the lumen of the urinary bladder or prostatic/penile urethra. Histologically, the calculi were composed of numerous sperm embedded in abundant brightly eosinophilic matrix. Based on gross and histologic findings, RE associated sperm cystolithiasis was diagnosed, with ulcerative urethritis as the major primary apparent etiology. To the authors' knowledge, this is the first report of four spontaneous cases of sperm cystolithiasis in rhesus macaques., (Copyright © 2013 Elsevier GmbH. All rights reserved.)

Objective: To compare required time and costs of surgery and hospitalization as well as prevalence of incomplete urinary cystolith removal associated with laparoscopic-assisted cystotomy versus open cystotomy in dogs., Design: Retrospective case series., Animals: 20 dogs with urolithiasis treated by laparoscopic-assisted cystotomy and 23 dogs treated by open cystotomy., Procedures: Medical records were reviewed. Surgery cost, hospitalization cost, total cost, surgery time, days in hospital, incomplete cystolith removal, and number of doses of analgesic administered IV after surgery were compared between the laparoscopic-assisted cystotomy and open cystotomy groups. Results-Surgery cost and total cost were significantly higher in the laparoscopic-assisted cystotomy group. Hospitalization cost, days in hospital, and prevalence of incomplete cystolith removal did not differ significantly between groups. Number of doses of analgesic was significantly lower in the laparoscopic-assisted cystotomy group., Conclusions and Clinical Relevance: Laparoscopic-assisted cystotomy was more time-consuming and expensive but associated with fewer postoperative doses of injectable analgesics, compared with open cystotomy. Laparoscopic-assisted cystotomy is an acceptable, more expensive, and minimally invasive alternative to open cystotomy for the removal of urinary cystoliths in dogs.

This report describes a modification of the parainguinal approach for removal of cystic calculi: a ventral midline laparotomy-guided parainguinal laparocystotomy. The ventral midline approach to the abdomen is rapid and routinely used by equine surgeons. With an arm introduced to the abdomen via the ventral midline, the surgeon is able to select the ideal parainguinal laparotomy incision location that allows bladder exteriorisation with the minimum amount of tension. Because the surgeon's hand is introduced via the ventral midline incision, the parainguinal incision can be sized to just allow exteriorisation of the urinary bladder and urolith, increasing extra-abdominal bladder security during cystotomy while reducing incision size in the parainguinal region. Finally, an assistant's hand via the ventral midline incision can maintain bladder stability within the parainguinal incision during cystotomy closure., (© 2012 EVJ Ltd.)

This report describes the outcomes of a modified laparoscopic-assisted cystotomy for urolith removal in dogs and cats. Modifications of the original techniques included a temporary cystopexy to the abdominal wall, utilization of a laparoscope instead of cystoscope, and retrograde flow of saline in the bladder with pressurized saline. The medical records of 23 client-owned animals for which laparoscopic-assisted cystotomy was used for urolith extraction were reviewed. Twenty-six procedures were performed in 23 animals. There were intraoperative complications in 19.2% of cases leading to open conversion in 11.5%. Rate of complications directly related to the procedure was 11.5%. Four cases had documented urolith recurrence with a mean time to recurrence of 335 days.

Objective: To evaluate the effect of preoperative antimicrobial administration on culture results in dogs undergoing cystotomy as a treatment for urolithiasis., Design: Prospective controlled study. Animals-41 dogs undergoing cystotomy for cystic calculi removal., Procedures: Urine samples were collected at time of anesthetic induction and during surgery prior to cystotomy, and a mucosal biopsy and culturette swab was collected during surgery from a control group, which received antimicrobials only after surgical culture sample collection, and from an experimental group, which received antimicrobials at the time of anesthetic induction., Results: 17 of 41 patients had positive culture results at anesthetic induction. Twenty of 41 patients had positive results of cultures for the surgical sample. No dogs that had positive results before antimicrobial administration had negative results after antimicrobial administration. There were no significant changes to urinalysis results regardless of group. Calcium monohydrate uroliths were the most common stone removed (24/41), followed by magnesium ammonium phosphate uroliths (11/41)., Conclusions and Clinical Relevance: There was no difference in culture results (positivity and bacterial type) when antimicrobials were given at anesthetic induction versus after surgical culture sample collection for dogs undergoing cystotomy for cystic calculi removal.

In July 2009, a 14-yr-old male caracal (Caracal caracal) at the National Zoological Gardens of South Africa was found, on abdominal ultrasound, to have a single large cystolith. The cystolith was removed, and the composition was determined to be 100% cystine. Blood and urine samples were also collected from three other apparently healthy caracals at the zoo and were submitted, together with the samples from the affected animal, for analysis using gas chromatograph mass spectrometry for cystine, lysine, alanine, and ornithine levels. The cystine levels in the urine, the fractional excretion of cystine, and the normalized excretion of cystine (micromol/g of creatinine) were all higher in the affected caracal than in the healthy animals. Only a single other case of cystine urolithiasis has been previously reported in any wild felid in the literature.

Objective: To report a technique for improving surgical access to the bladder for removal of cystic calculi in male horses., Study Design: Retrospective case series., Animals or Sample Population: Geldings (8) with cystic calculi., Methods: After catheterization of the bladder through the penis, 100 mL 2% lidocaine hydrochloride solution was instilled. After 10 minutes, the bladder was distended with sterile, warmed Hartmann's solution to a pressure of ≈ 40 cm H(2) O, using gravity feed. This was left in place until abdominal access was gained at surgery, then the fluid siphoned off via the catheter., Results: Calculi were 3-11 cm in diameter (median, 6 cm). Bladder capacity ranged from 1.4 to 2.5 L (median, 1.8 L). Exteriorization time from placing a hand in the abdomen to having the bladder in a surgically accessible position was <5 minutes., Conclusion: The described technique facilitates exteriorization of the bladder for removal of cystic calculi., (Copyright 2012 by The American College of Veterinary Surgeons.)

Objective: To report laparoscopic-assisted cystotomy and inguinal cystostomy for treating bladder urolithiasis in a gelding., Study Design: Clinical report., Animals: Twelve-year-old Appaloosa gelding., Methods: A laparoscopic approach was used to locate and grasp the bladder, which was exteriorized through an enlarged instrument portal for cystotomy to remove the calculus. During withdrawal, the calculus fragmented into multiple pieces. To avoid urethral occlusion and facilitate elimination of these fragments, an inguinal cystostomy was created. The seromuscular layer of the bladder was circumferentially secured to the abdominal fascia and bladder mucosa margins were sutured to the skin., Results: At 2-year follow-up, the gelding was in good condition with mild urine scald of the left ventral abdomen., Conclusion: Laparoscopic-assisted cystotomy was used for calculus removal and inguinal cystostomy for successful fragment elimination., (© Copyright 2012 by The American College of Veterinary Surgeons.)

Objective: To report use of transendoscopic electrohydraulic shockwave lithotripsy for fragmentation of urinary calculi in horses., Study Design: Case series., Animals: Male horses (n = 21)., Methods: Fragmentation of cystic calculi (median, 6 cm diameter; range, 4-11 cm diameter) was achieved by transurethral endoscopy in standing sedated horses using an electrohydraulic shockwave fiber introduced through the biopsy channel of an endoscope. The fiber was advanced until it contacted the calculus. Repeated activation of the fiber was used to disrupt the calculus into fragments <1 cm diameter. Visibility within the bladder was maintained by repeated lavage with saline solution., Results: Complete calculus removal was achieved in 20 horses (95%) with mean total surgical time of 168.6 minutes (range, 45-450). In the 20 horses with single calculi, 1-6 sessions were required to completely fragment the calculus. Except for 1 horse, in which perineal urethrotomy was eventually performed for complete fragment removal, fragments calculi were excreted via the urethra. Postoperative complications included hematuria because of severe mucosal erosion (n = 2), dysuria because of a trapped urethral fragment (2), small amount of urinary debris (1). One horse was euthanatized because of bladder rupture. Complete clearance of calculi and urinary debris was confirmed endoscopically 20 (3-45) days after the last session. Telephone follow-up (mean, 18.8 months; range, 7-24 months) revealed that horses had returned to previous activity levels without recurrence of clinical signs., Conclusions: Transendoscopic electrohydraulic lithotripsy appears to be an effective method for fragmentation of low-density calcium carbonate cystic calculi in male horses., (Copyright 2012 by The American College of Veterinary Surgeons.)

Magnesium ammonium phosphate (struvite) is one of the most common minerals found in feline uroliths. Previous studies have shown the efficacy of acidifying calculolytic diets (inducing urine pH < 6.5), in dissolving struvite stones in cats. Recent work in our laboratory found that wet and dry test diets induce a struvite urinary relative supersaturation (RSS) < 1 and that the urine of healthy cats fed the dry test diet dissolved feline struvite stones in vitro. The objective of the present study was to demonstrate the efficacy of those test diets on naturally occurring struvite urocystoliths in cats. A total of twenty-one cats were used, of which seventeen completed the study. Of the seventeen cats, eight were fed the wet test diet and nine the dry test diet. Uroliths dissolved in a median of 18 (10-55) d. In the remaining four cats, uroliths failed to dissolve and were removed surgically. Quantitative analysis showed that these uroliths contained either calcium oxalate or calcium phosphate. The present study demonstrates that diets that induce a struvite RSS < 1 result in struvite stone dissolution in vivo.

Two male dogs were presented with cystic uroliths composed of magnesium ammonium phosphate (struvite). Each had an atypical nidus, a mouse barley awn (Hordeum murinum). To our knowledge, this is the first report of grass awns located in the bladder lumen of dogs. The composition of uroliths and the pathophysiology of grass awn migration to the urinary bladder are discussed.

Objective: To report outcome of horses after standing pararectal cystotomy for removal of uroliths., Study Design: Case series., Animals: Horses (n=9) with cystic calculi., Methods: Medical records (December 1998-May 2007) of horses with cystic calculi that had standing pararectal cystotomy were reviewed. Signalment; urolith number, size, and type; surgical technique; sedation and analgesia protocols; intra- and postoperative complications and outcome were analyzed., Results: Uroliths (mean diameter, 6.37 cm; median, 6 cm; range, 3-10 cm) were removed intact without need for fragmentation. Eight (89%) horses had no complications and 1 horse (11%) developed persistent drainage from the perineal incision and incisional healing was prolonged. The complications resolved after wound revision, and although cystoscopy showed absence of uroliths, the clinical signs associated with cystitis recurred., Conclusions: Cystic calculi can be removed safely in standing horses using a pararectal approach. The procedure was well tolerated and no serious complications were encountered., Clinical Relevance: Pararectal cystotomy allows removal of cystic calculi in standing sedated horses. The technique may offer an economic advantage over approaches that require general anesthesia.

Objective: To determine the effectiveness of cystotomy for complete removal of urocystoliths and urethroliths in dogs, the types and frequency of diagnostic imaging performed to verify complete urolith removal, the complications that develop as a result of cystotomy, and predictors of each of these variables., Design: Retrospective case series., Animals: 128 dogs that underwent a cystotomy for removal of urocystoliths, urethroliths, or both from 1994 through 2006., Procedures: The following data were obtained from medical records: sex, body weight, number and locations of lower urinary tract uroliths identified in preoperative and postoperative imaging reports, types of imaging used for urolith detection, number of uroliths recovered during cystotomy, quantitative urolith composition, and major complications attributable to cystotomy. Objective criteria were applied to determine whether a cystotomy failed or succeeded and whether appropriate imaging was performed. Associations between potential prognostic factors and outcomes were statistically assessed., Results: Effectiveness of cystotomy could be determined in 44 (34%) dogs, of which 9 (20%) had incomplete removal of uroliths. Appropriate postoperative imaging was performed for only 19 (15%) dogs, of which 8 had incomplete removal. Dogs with both urethroliths and urocystoliths were more likely to have a failed cystotomy than dogs with only urethroliths or urocystoliths. Complications developed in 5 (4%) dogs., Conclusions and Clinical Relevance: Cystotomy was a safe and effective surgical procedure for removal of lower urinary tract uroliths in most dogs. Failure to remove all uroliths occurred in a substantial percentage of patients.

Objective: To compare accuracy of estimates of cystolith size obtained by means of plain radiography, double-contrast cystography, ultrasonography, and computed tomography., Sample Population: 30 canine cystoliths ranging from 1 to 11 mm in diameter with various mineral compositions., Procedures: A bladder phantom model was created by filling a rubber balloon with saline (1% NaCl) solution and positioning it on top of a 2% gelatin cushion at the bottom of a water-filled 4-quart container. Cystoliths were individually placed in the bladder phantom and imaged by each of the 4 techniques. For each image, cystolith size was measured by 2 radiologists with computerized calipers, and size estimates were compared with actual cystolith size., Results: Mean cystolith size estimates obtained by means of radiography, cystography, and computed tomography did not differ significantly from each other. However, for ultrasonographic images, mean +/- SD difference between actual and estimated cystolith size (2.95 +/- 0.73 mm) was significantly higher than mean difference for radiographic, cystographic, and computed tomographic images. For ultrasonography, mean +/- SD percentage overestimation in cystolith size was 68.4 +/- 51.5%., Conclusions and Clinical Relevance: Results indicated that measurements of cystolith size obtained by means of ultrasonography may overestimate the true size. This suggests that cystolith size estimates obtained by means of ultrasonography should be interpreted with caution whenever cystolith size may influence patient management.

Objective: To characterize the efficacy and safety of laser lithotripsy in the fragmentation of urocystoliths and urethroliths for removal in dogs., Design: Prospective case series., Animals: 100 dogs with naturally occurring urocystoliths and urethroliths., Procedures: Via cystoscopy, laser lithotripsy was performed to fragment uroliths. Basket retrieval and voiding urohydropropulsion were used to remove fragments. Postprocedural contrast cystography was performed to assess efficacy and safety. In 40 dogs, midstream urine samples were collected just prior to laser lithotripsy (day 0) and on days 1, 3, and 11 after laser lithotripsy to assess inflammation., Results: Urolith removal was complete in 82% of dogs (52/66 with only urocystoliths, 17/17 with only urethroliths, and 13/17 with urocystoliths and urethroliths). Urolith removal was incomplete in 18 dogs; of these dogs, 9, 6, and 3 had urolith fragments >or= 3 mm, 1 to < 3 mm, and < 1 mm in diameter, respectively. Sex (female) was the most significant predictor for success. Median procedure time was 72 minutes. Two dogs developed urinary tract obstruction following laser lithotripsy. Hematuria was detected in 53% of dogs on day 0 and in 84%, 13%, and 3% of dogs on days 1, 3, and 11, respectively. Leukocyturia was detected in 13% of dogs on day 0 and in 47%, 0%, and 3% of dogs on days 1, 3, and 11, respectively., Conclusions and Clinical Relevance: Results suggested that use of laser lithotripsy was a safe and effective alternative to surgical removal of urocystoliths and urethroliths in dogs.

Objective: To characterize and evaluate risk factors for suture-associated cystoliths in dogs and cats., Design: Retrospective case-control study. Animals-163 dogs and 13 cats with suture-associated cystoliths and 326 control dogs and 26 control cats with non-suture-associated cystoliths., Procedures: Submissions to the Canadian Veterinary Urolith Centre received from 1999 to 2006 were reviewed. Case dogs and cats had cystoliths associated with visible suture or with hollow, cylindrical channels or suture knot impressions consistent with dissolved suture. Control dogs and cats had at least a single recurrent non-suture-associated cystolith submitted closest in time to the sample case. Associations among cystolith composition, recurrence times, sex, age, and breed were evaluated., Results: Cases consisted of 92 dogs and 7 cats with visible suture and 71 dogs and 6 cats with dissolved suture. Suture-associated cystoliths represented 0.6% of canine cystoliths, 9.4% of recurrent canine cystoliths, 0.17% of feline cystoliths, and 4% of recurrent feline cystoliths. Sexually intact and neutered males were at increased odds of suture-associated cystoliths, relative to spayed female dogs. Shih Tzus, Lhasa Apsos, and Pomeranians were significantly predisposed to form suture-associated cystoliths. In dogs, compound suture-associated cystoliths were significantly more likely than other cystolith types (OR, 8.6). Dogs with suture-associated cystoliths had significantly shorter recurrence times than did control dogs., Conclusions and Clinical Relevance: Suture remnants in the bladder have an important role in recurrent cystolithiasis in dogs. Identification of risk factors is important for avoiding recurrence of iatrogenic cystoliths.

Background: Electrohydraulic lithotripsy (EHL) has been used as an alternative to cystotomy in human medicine to remove urinary calculi. This prospective study evaluated the efficacy and safety of EHL to remove urinary calculi in dogs., Hypothesis: EHL is an efficient and safe method of treatment of bladder and urethral calculi in dogs., Methods: Dogs presented between January 1, 2005 and June 1, 2007 with lower urinary tract calculi diagnosed by radiographs or ultrasound examination were included in the study. Physical examination, CBC, biochemistry, urinalysis, and urine culture were performed at presentation. EHL and voiding urohydropulsion were performed under general anesthesia. Patients received IV fluids for 12 hours after which they were rechecked by ultrasound examination and discharged with antibiotics and anti-inflammatory drugs for 5 days. All patients were reevaluated 1, 3, and 6 months after presentation by physical examination, urinalysis, and ultrasonography., Results: Twenty-eight dogs (19 males, 9 females) presented with bladder or urethral calculi or both underwent lithotripsy. Their median weight was 8.3 kg. Calcium oxalate calculi were present in 22 dogs, struvite in 4, and mixed calculi in 2. Fragmentation was done in the bladder (23 dogs) and in the urethra (12 dogs). Calculus-free rate was higher for urethral than for bladder calculi in males and higher for bladder calculi in females than in males. No major complications were reported. Twelve dogs relapsed within 6 months., Conclusions: Results of this study support the use of EHL as a minimally invasive treatment for bladder calculi in females and for urethral calculi in male dogs.

OBJECTIVE-To evaluate a laparoscopic technique for implantation of a urinary catheter in the right paramedian area in male sheep and to determine feasibility, benefits, and risks for this technique. DESIGN-Evaluation study. ANIMALS-6 Healthy male sheep (mean +/- SD body weight, 42.16 +/- 11.95 kg [92.75 +/- 26.29 lb]). PROCEDURES-Each sheep was anesthetized and positioned in dorsal recumbency. A 10-mm laparoscope was inserted in the right paramedian area between the xiphoid and preputial orifice. After creation of capnoperitoneum, grasping forceps were inserted in the left paramedian area at the level of the teats and used to immobilize the urinary bladder. A pigtail balloon catheter was implanted transcutaneously in the right paramedian area between the preputial orifice and teats and directed into the urinary bladder by use of laparoscopic guidance. The catheter was removed 10 days after implantation. Fourteen days after initial surgery, a second laparoscopy was performed to evaluate pathologic changes. RESULTS-Inadvertent insertion of the first trocar into the rumen of 1 sheep was the only intraoperative complication encountered. Laparoscopic-assisted implantation of the urinary catheter was successfully performed in all sheep. No postoperative complications were detected. CONCLUSIONS AND CLINICAL RELEVANCE-Laparoscopic-assisted implantation of a urinary catheter in the right paramedian area was successfully performed and may be a feasible method for use in sheep. This method can be considered as an alternative to tube cystotomy performed by laparotomy.

Ossification of the bladder wall, detected radiographically as a nonhomogeneous radiopaque area in the cranioventral part of the bladder in a puppy, is reported. We speculate that chronic inflammation due to the presence of uroliths in the lumen may have stimulated a metaplastic transformation of the cells.

Urolithiasis and carcinoma of the urinary bladder are generally uncommon in rats. In particular, spontaneous urolithiasis and carcinoma of the bladder in young rats has not yet been reported. Our case concerns the unexpected finding of urolithiasis of the bladder and left kidney of an apparently healthy 4-mo-old male Wistar rat. The bladder was filled with 28 white, round to oval calculi of various sizes. The kidney presented a single unevenly shaped calculus in the pelvis. Histology revealed, in addition to urolithiasis, a grade II papillary transitional cell carcinoma of the bladder, with muscle invasion and neoplastic extension to the left renal pelvic epithelium. No previous experimental procedure or dietetic manipulation had occurred, which could be held responsible for these findings. These unusual findings indicate that, unknown to researchers, unapparent factors can affect the health status of even relatively young experimental animals. Asymptomatic disease, such as the unknown presence of a tumor, potentially can affect many parameters and thus influence research results.

Objective: To describe a technique for laparoscopic-assisted removal of cystic calculi in geldings and report outcome., Study Design: Clinical report., Animals: Four geldings with cystic calculi., Methods: Laparoscopic-assisted cystotomy and urolith retrieval was performed in 4 anesthetized geldings positioned in dorsal recumbency. With a laparoscope portal located at the umbilicus, the abdomen was insufflated and then the surgical table was tilted (30 degrees head-down position) before an instrumental portal was created parallel and 2-3 cm medial to the left external inguinal ring. Laparoscopic grasping forceps were inserted to grasp the cranial aspect of the bladder and elevate it to the ventral abdominal wall. With the instrumental portal as mid-point, the parainguinal skin incision was longitudinally extended cranial and caudal (approximately 8-10 cm) to accommodate the size of the urolith. The apex of the bladder was exteriorized and sharply incised, the urolith extracted, and after cystotomy closure, the bladder was repositioned. The mini-laparotomy and trocar incisions were closed in layers., Results: There were no intra- or post-operative complications. All horses had minor incisional swelling for 3-4 days. No signs of abdominal or incisional pain were observed. Hematuria and slight stranguria occurred until the 3rd or 4th day. Surgical time (skin incision to skin closure) was 35-40 minutes. On long-term follow-up (up to 12 months) no recurrence of clinical signs associated with cystic calculi occurred., Conclusion: Uroliths (6-8 cm diameter) can be removed by laparoscopic-assisted cystotomy in geldings., Clinical Relevance: Laparoscopic-assisted cystotomy combines the advantages of the parainguinal laparocystotomy with laparoscopic technique for removal of cystic calculi while avoiding their disadvantages.