Urolith Type Research Articles

A retrospective study on epidemiology and management of canine cystine uroliths in one part of Norway from 2015 to 2020

BackgroundUrinary tract problems are a common complaint in small animal medicine and urolithiasis is considered to be an important cause of urinary tract disease in dogs. In this study the main aim was to investigate whether the occurrence of cystine urolithiasis increased during a five-year period. A second aim was to evaluate possible risk-factors as breed, age and gender. This study also evaluated how urine specific gravity, pH and level of cystine in urine responded to preventive strategies. Medical records of dogs with urolithiasis presented at nine Norwegian animal clinics and one animal hospital between 2015 and 2020 were retrospectively reviewed.ResultsThe incidence of cystine uroliths increased significantly during the five study years (R2 = 0.72, P = 0.0199). Dogs with cystine uroliths were significantly younger (5.0 years (n = 84, 95% CI [4.4–5.6])) when they were diagnosed with cystine uroliths compared to dogs with other types of uroliths (8.1 years (n = 255, 95% CI[7.8-8.5]) P < < 0.0001). Cystine levels in urine were increased in 93% of the dogs with cystine urolithiasis. Cystinuria decreased significantly after neutering (P < 0.0001). Breeds most commonly affected with cystine urolithiasis in this study were Staffordshire bull terrier, Danish Swedish farmdog and Chihuahua.ConclusionsThe results from this study supports a suggested genetic basis for cystine urolithiasis as described in previous studies. Neutering is considered an important part of preventing reoccurrence since cystine values decreased significantly after neutering.

Trends in urolith composition and factors associated with different urolith types in dogs from the Republic of Ireland and Northern Ireland between 2010 and 2020.

The purpose of this study was to determine changes in urolith trends and factors associated with different urolith types in dogs from the Republic of Ireland and Northern Ireland between 2010 and 2020. A laboratory database was searched for canine urolith submissions between 2010 and 2020. Trends in urolith composition between 2014 and 2020, and associations between patient characteristics with each urolith type were evaluated. A total of 1162 submissions were included. Struvite (39.0%), calcium oxalate (27.8%) and compound (10.2%) were the most prevalent uroliths. Calcium oxalate urolith (CaOx) incidence significantly increased from 27.8% to 31.2% and that of struvite significantly decreased from 41.7% to 33.0% between 2014 and 2020. Struvite uroliths were overrepresented among females compared to males (odds ratio 8.7, 95% confidence interval 6.6 to 11.5). Males (odds ratio 9.6, 95% confidence interval 6.9 to 13.3) and dogs >7 years of age (odds ratio 4.1, 95%, confidence interval 3.0 to 5.4) were more likely to have CaOx while males (odds ratio 9.6, 95% confidence interval 5.3 to 17.8) and dogs ≤7 year of age, purine uroliths (odds ratio 3.0, 95% confidence interval 1.8 to 5.0). Incidence was higher in bichon frise (odds ratio 1.7, 95% confidence interval 1.3 to 2.4) and Yorkshire terrier (odds ratio 2.8, 95% confidence interval 1.9 to 4.1) for CaOx and higher in shih-tzu for compound uroliths (odds ratio 1.7, 95% confidence interval 1.1 to 2.7) compared to the remaining reported breeds. Factors associated with different uroliths were similar to the ones previously reported. Proportion of CaOx submissions increased and that of struvite decreased over the study period which was in agreement with the changes identified in other European countries.

Treatment and surgery for management of urolithiasis

Urolithiasis is a common condition in steers and bulls due to nutritional and anatomical factors. Prevention practices share common aspects as well as aspects specific to certain urolith types. In this presentation we will discuss the underlying fac­tors and preventive measures for urolithiasis in cattle, as well as surgical management. Restraint, sedation, surgical ap­proaches and postoperative considerations will be discussed for both salvage procedures as well as cattle with breeding potential.

The most common types of uroliths larger than 1mm are readily visible and accurately measured in an in vitro setting mimicking the canine abdomen using digital radiography.

Abdominal radiography is an important diagnostic to detect uroliths. Cystine and urate uroliths were historically characterized as nonmineral opaque on survey radiographs. However, recent research and clinical observations indicate that pure urate and cystine uroliths may be detected with digital radiography. The primary purpose of this prospective, in vitro, diagnostic accuracy study was to determine the sensitivity of digital radiography in detecting cystoliths of varying size and composition. Forty canine uroliths of pure composition (10 each of calcium oxalate, struvite, cystine, and urate), acquired from Minnesota Urolith Center and ranging from 1 to 10mm, were placed in phantoms of three various sizes and radiographed. The radiographs, including three sets of each urolith separately, were evaluated by three blinded radiologists on two separate occasions. Evaluation included presence or absence of urolith, number of uroliths, and maximum diameter of the urolith(s). For all four types of uroliths and all readers, the specificity and PPV were 100% with an associated very high sensitivity (94.4%-98.9%) and NPV (94.8%-98.9%). Calcium oxalate uroliths were the most accurately measured and struvite were the least accurately measured when compared with the gross measurement. Smaller uroliths were more accurately measured than larger uroliths. Uroliths placed in smaller bladder phantoms were more accurately measured than in larger bladder phantoms. Though accurate measurement of uroliths is complicated by and dependent on numerous variables, our results reveal that urate and cystine uroliths are visualized on digital radiography making them a relevant differential diagnosis when seen clinically.

Retrospective analysis of 131 feline uroliths from the Republic of Ireland and Northern Ireland (2010-2020)

BackgroundThe proportions of different urolith types have not been investigated in cats from the Republic of Ireland (ROI) and Northern Ireland (NI) previously. The objective of this study was to investigate the proportions of different feline urolith types submitted to Minnesota Urolith Center from the ROI and NI from 2010 to 2020. An additional aim of this study was to identify potential risk factors associated with each urolith type in cats in this geographic area.ResultsOne hundred and thirty-one uroliths were submitted for the studied period with 44.3% being struvite, 43.5% calcium oxalate and 7.6% compound. Only 11 uroliths were submitted in the first 4 years. The number of submissions increased after 2015, peaking in 2019 with 25 submissions. Due to low numbers no conclusions could be made about changes in incidence of urolith types over time. Cats ≤7 years of age were significantly more likely to be diagnosed with struvite uroliths (OR, 2.87 [1.37-6.06]; p = 0.007) while cats ≥7 years of age with calcium oxalate uroliths (OR, 2.67, [1.29-5.37], p = 0.004).ConclusionsThis is the first epidemiologic study of urolithiasis from cats in the ROI and NI. The most prevalent types of uroliths in our study population were struvite and calcium oxalate. Due to the low number of urolith submissions, changes in the incidence of different uroliths could not be accurately determined. Increasing age was associated with calcium oxalate formation while younger cats were more commonly diagnosed with struvite urolithiasis which can be medically dissolved. Therefore, urolith dissolution is more likely to be successful in young cats than older cats.

Nutritional management of urolithiasis in dogs and cats

Background: An increasing number of techniques are becoming available for the management of canine and feline uroliths. Some require referral to a specialist hospital and can be costly and/or invasive. When used appropriately, dietary manipulation may reduce the need for such interventions and can delay or prevent urolith recurrence.Aim of the article: This article focuses on nutritional management options for a variety of urolith types, and outlines the clinical settings in which these options are appropriate.

Small ruminant urinary obstruction: decision trees for treatment.

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.

RETROSPECTIVE REVIEW OF UROLITHIASIS-RELATED MORBIDITY AND MORTALITY IN ASIAN COLOBINE MONKEYS.

Obstructive and incidental urolithiasis cases were evaluated in 5 Asian colobine monkey species (n= 21 individuals) that included 12 silvery langurs (Trachypithecus cristatus), 6 spectacled langurs (Trachypithecus obscurus), 1 Javan langur (Trachypithecus auratus auratus), 1 François' langur (Trachypithecus francoisi), and 1 red-shanked douc langur (Pygathrix nemaeus) from eight zoologic institutions. All institutions that responded were Association of Zoos and Aquariums, European Association of Zoos and Aquaria, or World Association of Zoos and Aquariums accredited. Males were more commonly represented in the total number of cases (86%), and all cases of obstructive urolithiasis occurred in males. The most common clinical signs observed in obstructive cases included stranguria (58.8%), lethargy (41.2%), anorexia (29.4%), depression (17.6%), and penile manipulation (11.8%). Clinicopathologic abnormalities revealed azotemia (76.5%), anemia (35.3%), and hyperkalemia (23.5%). Eleven of the 21 cases included urinalysis results, and crystalluria was reported in all 11. Obstructive cases were more commonly managed surgically, with medical management following. Instances of individual obstruction ranged from 0 (incidental finding) to 18, with a median of 8 (mean of 4.3) recurrent obstructions. A total of 39 urolith analyses were available from 17 of 21 cases, with calcium carbonate being the most common type isolated (37 of 39, 94.9%). Calcium oxalate was observed in the remaining 5.1% of cases (2 of 39). No cases exhibited a consistent match of crystalluria and urolith type. Death or euthanasia secondary to obstructive urolithiasis occurred in 52.4% of cases. Urinary obstruction secondary to urolithiasis appears to be a relevant cause of morbidity and mortality in Asian colobine species, and further study into etiology and preventive medicine should be undertaken.

Диагностические возможности качественного экспресс-анализа минералогической структуры уролитов

the aim of the determination of the diagnostic information content of the qualitative analysis method - urinary calculus for use in medical practice in the study of the chemical structure of urolite. Materials, methods: Determination of the chemical composition of uroliths in the collection of urinary stones (n=2960), presented in "a Database of patients with urolithiasis who live in the territory of the Republic of Belarus" (2006-2019), made the developed method of qualitative analysisbased on the combined conduct of optical macroscopy of the sample, qualitative chemical reactions and chemical reactions of reprecipitation with subsequent microscopy of the crystals formed.The developed method allowed identifying the following clinically most significant mineral components of urinary stones: vevellite (42.4%), weddellite (28.1%), Apatite (19.6%), carbonate Apatite (5.1%), struvite (13.2%), uric acid (17.6%), ammonium urate (0.4%), cystine (0.7%). The obtained data were consistent with the results of studying the elemental composition of urinary stones (n=24) by atomic emission spectrometry with inductively coupled plasma. The calcium level was highest in calcium stones (25.56% C oxalate and 19.73% C phosphate) with a minimum content (0.012%) in urate stones. The amount of magnesium prevailed in the group with magnesium-ammonium-phosphate stones (2.51%) at extremely low concentrations in urate samples (7.810-4%). The percentage of phosphorus was maximum (13.47%) in the group of uroliths, represented by phosphate salts of calcium and magnesium (with values of 0.67% - calcium oxalate and 0.013% urate). Identification of trace elements Al, Ba, Cu, Fe, Zn, Sr revealed a fluctuation in their content in the range from 0.037 to 546.3 ppm.Considering the practical availability of implementation, low financial costs and sufficient information, the method of qualitative rapid analysis of urinary stone, based on a combined optical macroscopy of the sample, qualitative chemical reactions and chemical reactions of reindeposition with subsequent microscopy of the formed crystals, can be recommended for wide use in medical institutions of any regional level in the diagnosis of chemical types of uroliths in patients with ICD.

Correction: Variation in mineral types of uroliths from ferrets (Mustela putorius furo) submitted for analysis in North America, Europe, or Asia over an 8-year period

"Correction: Variation in mineral types of uroliths from ferrets (Mustela putorius furo) submitted for analysis in North America, Europe, or Asia over an 8-year period" published on 15 Dec 2021 by American Veterinary Medical Association.

Variation in mineral types of uroliths from ferrets (Mustela putorius furo) submitted for analysis in North America, Europe, or Asia over an 8-year period.

To compare mineral types of naturally occurring uroliths in ferrets (Mustela putorius furo) from North America, Europe, and Asia and to identify potential risk factors associated with cystine urolithiasis in ferrets. 1,054 laboratory submission records of uroliths obtained from ferrets between January 1, 2010, and December 31, 2018. For this cross-sectional study, the medical records databases at 4 diagnostic laboratories were searched for records of submissions of uroliths obtained from ferrets. Data collection included submission date; ferret sex, neuter status, and age; receiving laboratory and continent; and urolith mineral type. Regression analyses were performed to identify variables associated with cystine uroliths. Of the 1,054 urolith submissions, 1,013 were from North America, with 92.6% (938/1,013; 95% CI, 90.8% to 94.1%) cystine uroliths, and 41 were from Europe and Asia, with only 26.8% (11/41; 95% CI, 15.7% to 41.9%) cystine uroliths. Median age was 2.0 years for ferrets with cystine urolithiasis versus 4.0 years for those with other types of uroliths. Submissions were more likely cystine uroliths for ferrets in North America versus Europe and Asia (adjusted OR [aOR], 59.5; 95% CI, 21.4 to 165.6), for ferrets that were younger (aOR, 0.67; 95% CI, 0.58 to 0.77), or for submissions in 2018 versus 2010 (aOR, 21.1; 95% CI, 5.1 to 87.9). Results indicated that the proportion of submissions that were cystine uroliths dramatically increased in North America between 2010 and 2018. There is an urgent need to determine underlying causes and mitigate cystine urolithiasis in ferrets.

Urolithiasis in cats: Evaluation of trends in urolith composition and risk factors (2005-2018).

BackgroundUrolithiasis is an important upper and lower urinary tract disease in cats that results in morbidity and mortality.ObjectiveTo describe trends in composition of uroliths in cats and evaluate risk factors related to age, breed, sex, urolith location, and bacterial urolith cultures.Sample PopulationA total of 3940 uroliths and the cats from which they were obtained.MethodsThe database of the UC Davis Gerald V. Ling Urinary Stone Analysis Laboratory was searched for all urolith submissions from cats between January 2005 and December 2018. Mineral type, age, breed, sex, and urolith location and culture results were recorded. Trends were evaluated and variables compared to evaluate risk factors.ResultsA significant decrease in the proportion of calcium oxalate (CaOx)‐containing uroliths occurred over time (P = .02), from 50.1% (204/407) of all submissions in 2005 to 37.7% (58/154) in 2018. In contrast, the proportion of struvite‐containing uroliths increased significantly (P = .002), from 41.8% (170/407) in 2005 to 54.5% (84/154) in 2018. The proportion of CaOx‐containing uroliths in the upper urinary tract was significantly higher compared to the proportion of other urolith types in the upper urinary tract. Urate‐containing uroliths were the third most common type (361/3940, 9.2%). Overall, sex and age predispositions were similar to those reported previously.Conclusions and Clinical ImportanceThe decrease in the proportion of CaOx‐containing uroliths and increase in the proportion of struvite‐containing uroliths warrants investigation. Further education regarding the efficacy of medical dissolution of struvite‐containing uroliths is recommended.

Analysis of 7866 feline and canine uroliths submitted between 2014 and 2020 in the Netherlands

Analysis of large datasets of uroliths is necessary to illustrate the prevalence and risk factors of urolithiasis. Furthermore, it may help to improve treatment and prevention of urolithiasis. In this study, 7866 uroliths (44.5% feline and 55.5% canine) from veterinary practitioners in the Netherlands between 2014 and 2020 were analysed. Between 2014 and 2020 the distribution over the different types of uroliths remained similar over time. Female cats, obese cats, Domestic Shorthair cats, female dogs, and large breed dogs had an increased risk for struvite. Neutered cats, all cat breeds except Domestic Shorthair, neutered dogs, male dogs, intact male dogs, and small breed dogs had an increased risk for calcium oxalate urolithiasis. Cystine and urate were found predominantly in male dogs. Dalmatians were at highest risk for urate urolithiasis. The findings of this study in the Netherlands were similar to findings in previous studies from different countries. However, urate urolithiasis in the English Cocker Spaniel and cystine urolithiasis in the Yorkshire Terrier were new associations. Body condition score, information about recurrence of urolithiasis, medical history, and diet history should be included in submission sheets in the future to explore other possible associations.

Occurrence of uroliths - age-, breed-, and gender-specific differences in dogs from Germany

The aim of this study was to assess the distribution and frequency of uroliths in dogs in Germany and to evaluate age-, gender-, and breed-specific differences. A total of 2772 uroliths from dogs in Germany that had been submitted from veterinary practices during the years 2017-2019 were analyzed by infrared spectroscopy. Uroliths were analyzed as follows: Struvite (44.7 %), calcium oxalate monohydrate (whewellite 24.5 %), cystine (15.2 %), ammonium urate (5.3 %), calcium oxalate dihydrate (weddellite 4.4 %), calcium phosphate (1.6 %), xanthine (1.2 %), whewellite/weddellite (11 %), brushite (0.4 %) and other substances (1.7 %). The dogs' median age (in years) with regards to the urolith type amounted to: struvite 8, calcium oxalate (whewellite and weddellite) 10, cystine 5, brushite 11, xanthine 6.5, and ammonium urate 6 years. Struvite uroliths were most common in intact females (83.8 %) and neutered females (80.8 %), while cystine uroliths (36.7 %) and calcium oxalates (35.7 % whewellite and weddellite) were most common in intact males. Calcium oxalate (50 %), struvite (17.3 %), and cystine uroliths (10.5 %) were found in male neutered dogs. The most frequent breeds with struvite uroliths were Pug (75.9 %), Labrador (73.1 %), Shih Tzu (62.2 %), Dachshund (50.4 %) and Maltese (36 %). Calcium oxalates were most frequently encountered in the breeds Miniature Schnauzer (54.8 %), Jack Russell Terrier (49.5 %), and Yorkshire Terrier (48.2 %). Cystine uroliths were most frequent in the breeds French Bulldog (47.2 %), Bulldogs (44.8 %), Chihuahua (44.1 %) and Dachshund (32.8 %). Dogs from Germany displayed age-, gender- and breed-specific differences in the frequency of urine calculi occurrence. Knowledge of the frequent occurrence of the distinct uroliths in Germany as well as potential breed dispositions allow the veterinarian to implement an appropriate preventive treatment plan. This would involve a targeted monitoring program for the prevention and follow-up care of the patient in conjunction with the pet owner.

Risk factors for, frequency, and type of complications after temporary tube cystostomy in goats, sheep, and pigs.

To describe risk factors for as well as type and frequency of complications, time to occurrence of complications, and mortality after temporary tube cystostomy alone or in combination with other surgical procedures, in goats, sheep, and pigs. Retrospective case series. One hundred thirteen goats, eight sheep, and six pigs. Medical records of goats, sheep, and pigs that underwent temporary tube cystostomy alone or in combination with urethrotomy at the Veterinary Medicine Teaching Hospital, University of California-Davis from January 1, 2007 to December 31, 2018 were reviewed. Signalment, presurgical and surgical procedures, urolith type and location, and postoperative complications and mortality were analyzed. In goats, logistic regression analysis was performed to determine association between the presence of complications or mortality as well as candidate predictor variables. Postoperative complications were reported in 54.9% (62/113) of goats, 37.5% (3/8) of sheep, and 50% (3/6) of pigs. The most frequent type of complication was reobstruction. Median (range) time to first complication was 171 days (1-2247) for goats. In sheep and pigs, the range for time to re-presentation for complications was 11 to 37 and 17 to 1182 days, respectively. Proportions of nonsurvivors after tube cystostomy were 48.4% (30/62) goats, 1/8 sheep and 2/6 pigs. No association between examined predictor variables and the occurrence of complications or mortality was detected. The risk of complications and mortality after temporary tube cystostomy was high, especially in goats. Owners should be made aware of the high complication rate after temporary tube cystostomy alone or in combination with other procedures. Investigation of alternative approaches to manage obstructive urolithiasis in goats, sheep, and pigs should be considered.

Epidemiology of feline urolithiasis in Mexico (2006-2017).

ObjectivesThe objectives of this study were to identify the proportions of different types of uroliths, characterize the population of cats that present with urolithiasis and determine possible predisposing factors in a population of Mexican cats.MethodsThis study analyzed clinical specimens of feline urolithiasis submitted to our laboratory in the period from 2006 to 2017. The mineral composition of the uroliths was determined by qualitative and quantitative mineral analyses, performed by stereoscopic microscopy and infrared spectroscopy.ResultsIn the population studied, 54.3% of all uroliths were calcium oxalate, followed by 32.1% struvite and 7.4% purine (urate and xanthine) uroliths, with other types accounting for 6.2% of submissions. The male:female ratio was 1.2:1. Calcium oxalate submissions were predominantly from males and struvite submissions were predominantly from females. The age of the cats with stone submissions ranged from 6 months to 17 years. In cats with calcium oxalate uroliths, 52.3% were aged 7 years or older. Cats with struvite uroliths were younger, with 65.4% younger than 6 years of age. Almost 90% of all submitted uroliths were from domestic shorthair cats.Conclusions and relevanceThis is the first epidemiologic study of urolithiasis in cats in Mexico. Age and sex predispositions to common uroliths were identified, as males aged ≥7 years primarily presented with calcium oxalate uroliths and females aged <6 years primarily presented struvite uroliths. Cases of urolithiasis of genetic origin, including xanthinuria and cystinuria, were also detected, in addition to silicate uroliths.

Особенности морфологии и структуры уролитов

According to statistical data of a number of the countries, have an urolithic disease from 5% to 15% of the population today. A recurrence arises at 50-85% of patients. The purpose of this work was complex studying of morphology, structure, mineral structure of urolit, identification of regularities of their formation, establishment of interrelation between mineral and organic matter in structure of urolit. the urinary stones from the urology departments of hospitals and clinics of the Tomsk region (Russia). s: crystallomorphological (the study of the surface morphology of uroliths binocular and trinocular microscopes); polarizing optical (study of the mineral composition of uroliths on a polarizing microscope); x-ray crystallography (the study of spectral composition on the apparatus DRON-3); electron microscopic (study of the peculiarities of morphology of crystals in an electron microscope). On features of morphology of a surface four types of urolit are allocated: druzovidny, sferolitovy, combined, korallovidny. Structural kinds of urolit: crystal and granular, dendritovidny, combined, rhythmic - zone. In structure of urolit the following types of rhythms are established: zone, granular, combined. In the urolitakh with rhythmic - the zone structure allocated elements of their building: kernel, layer, zone, rhythm. A mineral part of uric stones is presented by the crystals belonging to the classes: oxalates, phosphates, urat . The peculiarities of the morphology of the selected four types of uroliths: druzoid, with, combined, coral. Structural variations uroliths: crystal-grained Shelly, dendritic, combined, rhythmically zoned. In the structure of uroliths, the following types of rhythms: zoned, granular, combined. In urolith with rhythmically zoned structure selected elements of their structure: core, layer, area, rhythm. Morphological and structural features of the structure of urolites, especially the presence of rhythmic zoning, due to the alternation of layers of mineral and organic matter, indicate a close relationship between the living organism and the organo-mineral aggregate in the human urinary system. With a high degree of confidence we can talk about the symbiosis of living and mineral matter in the human body; as a result of this symbiosis, organic-mineral formations are formed, which are often the further cause of some diseases (for example, urolithiasis and cholelithiasis). The complex research of uric stones allows to obtain important information on their structure, structure and features of morphology. Morphological and structural features of the structure of urolit, in particular existence of the rhythmic zonality caused by alternation of layers of mineral and organic matter demonstrate close interrelation between a live organism and the organo-mineral unit in an urinary system of the person.

Epidemiology of urolithiasis in dogs from Guadalajara City, Mexico

Urolithiasis is a frequent and recurrent problem in dogs around the world. Several epidemiological studies based on mineral composition of uroliths have been carried out in different geographical areas. The objective of this study was to analyze epidemiological data of 195 dogs with urolithiasis from the metropolitan area of Guadalajara Jalisco, Mexico. To determine the chemical composition of uroliths, quantitative and qualitative analyses were performed by means of stereoscopic microscopy and infrared spectroscopy. The dogs` median age was six years and a male-female ratio of 1.4:1 was observed. The most affected pure breed dogs were schnauzer, poodle, Labrador retriever, Yorkshire terrier, and German shepherd. The frequency of uroliths of struvite, calcium oxalate, urates, mixes, and compounds, is similar to the one found in other studies performed in other populations. However, a much higher frequency of silicate-containing uroliths (16.92%) was observed, both in a pure form as well as in mineral mixtures. These results led us to suggest the need to develop further investigations to determine the origin of this high frequency.Figure 1. Different types of uroliths. Note the differences in shape, size, color, and number; however, none of these characteristics is specific to a particular mineral composition.

An experimental model for calcium carbonate urolithiasis in goats.

BackgroundCalcium carbonate is a common urolith type in small ruminants with no high‐yield experimental model to evaluate animal susceptibility or preventative measure response.HypothesisThat novel plastic winged implants would allow accumulation and quantification of calcium carbonate calculus formation in goats on a high‐calcium diet and identify individual variation between goats in the mass of calculi produced.AnimalsEight nonpregnant 3‐ and 4‐year‐old Boer‐cross does, weighing 22.3–39.5 kg, determined to be healthy based on physical examination, were used in these experiments.MethodsProspective cohort study for in vivo experimental model development. Implants were placed into the urinary bladder lumen in 8 goats over 2 evaluation periods. The alfalfa‐based ration had a total ration Ca : P of 3.29 and 3.84 : 1, respectively. Urine was collected at 0, 28, 56, and 84 days in the 1st experiment; blood and urine at those timepoints in the 2nd experiment. For each evaluation period, the implants were removed 84 days after implantation and weighed. Accumulated calculi mass was calculated and compared between goats and was analyzed for composition.ResultsImplant retention was 100% and 86% in the 2 studies. All goats with retained implants accumulated calcium carbonate at a mean implant gain per day across studies ranging from 0.44 to 57.45 mg. Two goats accumulated (0.44–7.65 mg/day and 33.64 & 57.45 mg/day) significantly more urolith material than the cohort across both studies (P = .047). No routine analytes on blood or urine were found to be explanatory for the difference observed.Conclusions and Clinical ImportanceThese findings form a basis for implant and diet selection for use in future studies of urolithiasis development and for studies regarding individual susceptibility to urolithiasis.

Dual-energy computed tomography of canine uroliths.

OBJECTIVE To determine whether dual-energy CT (DECT) could accurately differentiate the composition of common canine uroliths in a phantom model. SAMPLE 30 canine uroliths with pure compositions. PROCEDURES Each urolith was composed of ≥ 70% struvite (n = 10), urate (8), cystine (5), calcium oxalate (4), or brushite (3) as determined by standard laboratory methods performed at the Canadian Veterinary Urolith Centre. Uroliths were suspended in an agar phantom, and DECT was performed at low (80 kV) and high (140 kV) energies. The ability of low- and high-energy CT numbers, DECT number, and DECT ratio to distinguish uroliths on the basis of composition was assessed with multivariate ANOVA. RESULTS No single DECT measure differentiated all urolith types. The DECT ratio differentiated urate uroliths from all other types of uroliths. The DECT and low-energy CT numbers were able to differentiate between 8 and 7 pairs of urolith types, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that DECT was unable to differentiate common types of canine uroliths in an in vitro model; therefore, it is unlikely to be clinically useful for determining urolith composition in vivo. Given that the primary reasons for determining urolith composition in vivo are to predict response to shock wave lithotripsy and develop a treatment plan, future research should focus on the correlation between DECT measurements and urolith fragility rather than urolith composition.