Xanthinuria in a familial group of Munchkin cats and an unrelated domestic shorthair cat.

CASE SERIES SUMMARY: Four confirmed cases of xanthinuria in cats, and one suspected case based on pedigree analysis, were identified. Clinical presentations varied and included haematuria, pollakiuria, dysuria, and urethral and ureteral obstruction. All cats had upper urinary tract uroliths. Diagnosis was obtained through infrared mass spectrometry of uroliths or urine. Clinical signs commenced at 3-8 months of age and reduced in all cats in the medium to long term after the introduction of a protein-restricted diet. Four cats were castrated males and one was a spayed female. Cases consisted of four Munchkin pedigree cats and one unrelated domestic shorthair cat. All four affected Munchkin pedigree cats were related, with three cases full siblings and the fourth case a half-sibling. No connection to the Munchkin pedigree could be established for the domestic shorthair cat. A candidate causative genetic variant (XDH p.A681V) proposed for this cat was excluded in the Munchkin family. RELEVANCE AND NOVEL INFORMATION: All affected cats presented diagnostic challenges and routine urinalysis was insufficient to obtain a diagnosis. Cases of feline xanthinuria may be underdiagnosed due to situations where uroliths cannot be retrieved for analysis and there is an inability to make a diagnosis using crystal morphology alone on routine urinalysis. Metabolic screening of urine may provide an effective mechanism to confirm xanthinuria in suspected cases where uroliths are inaccessible or absent. In this case series, male cats were more common. Their anatomy may increase the risk of lower urinary tract signs and urethral obstruction developing secondary to xanthine urolithiasis. A protein-restricted diet appears to reduce clinical signs as part of long-term management. PLAIN LANGUAGE SUMMARY: Four closely related Munchkin cats and one domestic shorthair cat were found with a suspected genetic disease causing high levels of xanthine in their urine. The case series looks at similarities and differences in their clinical signs, as well as difficulties experienced in obtaining a correct diagnosis. All cats had upper urinary tract stones and required metabolic testing of the stones or urine to diagnose. All cats were young when their clinical signs started and were on a high-protein diet. Four cats were desexed males and one was a desexed female. A genetic variant that may have caused the disease in the domestic shorthair cat was ruled out in the Munchkin family. Cases of high xanthine levels in feline urine may be underdiagnosed as the stones may not be accessed for testing. In this case series, male cats were more common. Their anatomy may increase the risk of lower urinary tract signs. A protein-restricted diet appears to reduce clinical signs as part of long-term management.

Preoperative parameters (signalment, digital radiography, urinalysis, urine microbiological culture) and novel algorithm improve prediction of canine urocystolith composition.

OBJECTIVE: To determine the accuracy of 4 preoperative parameters (signalment, urinalysis, urine microbiological culture, and digital radiography) in predicting urocystolith composition, compare accuracy between evaluators of varying clinical experience and a mobile application, and propose a novel algorithm to improve accuracy. ANIMALS: 175 client-owned dogs with quantitative analyses of urocystoliths between January 1, 2012, and July 31, 2020. METHODS: Prospective experimental study. Canine urocystolith cases were randomly presented to 6 blinded "stone evaluators" (rotating interns, radiologists, internists) in 3 rounds, each separated by 2 weeks: case data alone, case data with a urolith teaching lecture, and case data with a novel algorithm. Case data were also entered into the Minnesota Urolith Center mobile application. Prediction accuracy was determined by comparison to quantitative laboratory stone analysis results. RESULTS: Prediction accuracy of evaluators varied with experience when shown case data alone (accuracy, 57% to 82%) but improved with a teaching lecture (accuracy, 76% to 89%) and further improved with a novel algorithm (accuracy, 93% to 96%). Mixed stone compositions were the most incorrectly predicted type. Mobile application accuracy was 74%. CLINICAL RELEVANCE: Use of the 4 preoperative parameters resulted in variable accuracy of urocystolith composition predictions among evaluators. The proposed novel algorithm improves accuracy for all clinicians, surpassing accuracy of the mobile application, and may help guide patient management.

Diagnosis and treatment of urolithiasis in a Toy Poodle dog.

Background: Urolithiasis in dogs is a disorder of the urinary tract caused by the development of crystals. These crystals are composed of minerals such as phosphates, oxalates, urates, cystine, carbonates, and silica. It can be fatal if the diagnosis and treatment are inaccurate. This report aims to report a case of urolithiasis in a Toy Poodle dog. Case Description: A 2-year-old male Toy Poodle dog weighing 4.2 kg with black hair, and having trouble urinating was presented to Prof. Soeparwi Animal Hospital, Universitas Gadjah Mada, Indonesia. The dog is examined physically and, in the laboratory, diagnosed and continued with operative therapy. The history and physical examination revealed that the dog had been experiencing hematuria, stranguria, and oliguria for 2 months, with the last few days accompanied by decreased appetite. The dog exhibited decreased skin turgor, a capillary refill time (CRT) of less than 2 seconds, signs of pain and distress during urination, and palpation of distended urinary vesicles. Ultrasound scans revealed uroliths in the urinary vesica, which were identified by an acoustic shadow. Blood tests indicated a decrease in hematocrit and erythrocytes along with an increase in leukocytes. Urolithiasis was diagnosed in the case dog based on anamnesis, physical examination, hematological examination, and ultrasonography. Subsequently, a cystotomy was performed, and uroliths located in urinary vesicles were removed. The dog received ceftriaxone injections at 15 mg/kg body weight and vitamin B-complex injections at a concentration of 10 mg/kg body weight for 5 days. Four days post-surgery, the case dog was able to successfully urinate and pass clean urine. Conclusion: The Toy Poodle dog was diagnosed with silica urolithiasis in the urinary vesicles and the urolith is quite large. Cystotomy was performed to remove the urolith. Postoperative care were included the administration of antibiotics and vitamins to facilitate the healing process. The condition of the Poodle toy dog improved.

Uroliths composed of antiviral compound GS-441524 in 2 cats undergoing treatment for feline infectious peritonitis.

Feline infectious peritonitis (FIP) historically has been a fatal disease in cats. Recent unlicensed use of antiviral medication has been shown to markedly improve survival of this infection. An 8-month-old female spayed domestic short-haired cat undergoing treatment for presumptive FIP with the antiviral nucleoside analog GS-441524 developed acute progressive azotemia. Abdominal ultrasound examination identified multifocal urolithiasis including renal, ureteral, and cystic calculi. Unilateral ureteral obstruction progressed to suspected bilateral ureteral obstruction and subcutaneous ureteral bypass (SUB) was performed along with urolith removal and submission for analysis. A 2-year-old male neutered domestic medium-haired cat undergoing treatment for confirmed FIP with GS-441524 developed dysuria (weak urine stream, urinary incontinence, and difficulty expressing the urinary bladder). This cat also was diagnosed sonographically with multifocal urolithiasis requiring temporary tube cystostomy after cystotomy and urolith removal. In both cases, initial urolith analysis showed unidentified material. Additional testing confirmed the calculi in both cats to be 98% consistent with GS-441524. Additional clinical studies are required to determine best screening practices for cats presented for urolithiasis during treatment with GS-441524.

Relative supersaturation values distinguish between feline urinary and non-urinary foods and align with expected urine analytes contributions to uroliths.

Introduction: Uroliths are concretions formed in the urinary tract. These can be problematic in humans and companion animals such as cats. Magnesium ammonium phosphate (struvite) and calcium oxalate (CaOx) are the most common forms of uroliths. The relative supersaturation (RSS) is a relative risk index of crystal formation. Here, an updated program for calculating RSS, EQUIL-HL21, was used to detect differences in RSS values when cats were fed foods formulated for urinary and non-urinary conditions. In addition, the contributions of urinary analytes to RSS values were examined via regression analyses. Methods: Historical data from feeding trials including foods indicated for use in urinary or non-urinary conditions were analyzed for nutrient composition and urinary parameters. RSS was calculated by EQUIL-HL21. The relationship between RSS values calculated by EQUIL-HL21 and urinary analytes was examined by regression models, which were selected by R2 and stepwise methods. Results: Cats that consumed urinary foods had significantly greater levels of urinary sodium and chloride compared with those that consumed non-urinary foods, consistent with the greater amounts of sodium and chloride in the urinary foods. Those that consumed non-urinary foods had higher urine pH, ammonium, potassium, phosphorus, magnesium, oxalate, citrate, and sulfate. Struvite RSS value and number of urinary crystals were significantly lower in cats fed the urinary foods. Mean CaOx RSS values were similar in both foods, though the number of CaOx crystals were significantly higher in cats that consumed non-urinary foods. A model predicting the natural log of struvite RSS values indicated that these values would increase with increasing urine pH, ammonium, chloride, calcium, phosphorus, and magnesium, and would decrease with increasing urine citrate and sulfate. CaOx RSS was predicted to increase as urinary chloride, calcium, and oxalates increased, and would decrease as urine pH, sodium, phosphorus, citrate, and sulfate increased. Discussion: These analyses demonstrate that the EQUIL-HL21 program can accurately detect expected differences between foods formulated for urinary and non-urinary indications. Regression models showed the eight urinary analytes that, respectively, contribute to the predicted RSS values for struvite and CaOx.

Risk factors for upper urinary tract uroliths and ureteral obstruction in cats under referral veterinary care in the United Kingdom.

BACKGROUND: Cats presenting with upper urinary tract uroliths (UUTUs) and ureteral obstruction ("obstructive UUTU") are typically younger than cats with idiopathic CKD that often have incidental nephroliths. HYPOTHESIS: Cats with upper urinary tract urolith have 2 clinical phenotypes; a more aggressive phenotype at risk of obstructive UUTU at a young age and a more benign phenotype in older cats, with reduced risk of obstructive UUTU. OBJECTIVES: Identify risk factors for UUTU and for obstructive UUTU. ANIMALS: Eleven thousand four hundred thirty-one cats were referred for care over 10 years; 521 (4.6%) with UUTU. METHODS: Retrospective VetCompass observational cross-sectional study. Multivariable logistic regression models were performed to identify risk factors for a diagnosis of UUTU vs no UUTU and additionally, obstructive UUTU vs nonobstructive UUTU. RESULTS: Risk factors for UUTU included female sex (odds ratio [OR] 1.6, confidence interval [CI] 1.3-1.9; P < .001), British shorthair, Burmese, Persian, Ragdoll or Tonkinese (vs non-purebred ORs 1.92-3.31; P < .001) breed and being ≥4 years (ORs 2.1-3.9; P < .001). Risk factors for obstructive UUTU were female sex (OR 1.8, CI 1.2-2.6; P = .002), having bilateral uroliths (OR 2.0, CI 1.4-2.9; P = .002) and age, with the odds of obstructive UUTU increasing as age at diagnosis of UUTU decreased (≥12 years, reference category; 8-11.9 years, OR 2.7, CI 1.6-4.5; 4-7.9 years, OR 4.1, CI 2.5-7.0; 0-3.9 years, OR 4.3, CI 2.2-8.6; P < 0.001). CONCLUSIONS AND CLINICAL IMPORTANCE: Cats diagnosed with UUTU at a younger age have a more aggressive phenotype with higher risk of obstructive UUTU compared to cats over 12 years of age diagnosed with UUTU.

Candidate causative variant for xanthinuria in a Domestic Shorthair cat.

Xanthinuria is a clinically significant form of urolithiasis in cats with poor clinical outcomes and limited treatment options. In humans, xanthinuria has an autosomal recessive mode of inheritance, with variants in xanthine dehydrogenase (XDH) and molybdenum cofactor sulfurase (MOCOS) responsible for cases. While causative genetic variants have not been identified in the domestic cat, a recessive mode of inheritance has been suggested. DNA was extracted from EDTA-stabilised blood obtained from a Domestic Shorthair cat with clinically confirmed xanthinuria. Whole-genome sequencing and variant assessment in XDH and MOCOS identified XDH:c.2042C>T (XDH:p.(A681V)) as a candidate causative variant for xanthinuria in this cat. The variant is located in a highly conserved part of the molybdenum-pterin co-factor domain, responsible for catalysing the hydroxylation of hypoxanthine to xanthine and uric acid. Variants in this domain of XDH have been shown to disrupt enzyme function and to cause xanthinuria in other species. When assessed in the wider cat population, the variant had an allele frequency of 15.8%, with 0.9% of the animals assessed homozygous for the alternative allele. Cats diagnosed with xanthinuria should be tested for this variant to validate its clinical relevance in the wider population.

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

BACKGROUND: The 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. RESULTS: One 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). CONCLUSIONS: This 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.

Cantharis dissolves calculus in the ureter of a kitten: case repor

Urolithiasis is a disease thatcan occur alone or together, obstruct the urinary flow, and even progress to the animal's death. Objective:The present study is to report the dissolution of calculus in the ureter in a kitten. Methodology: a feline, SRD, male, started at 3 months old with the signs of vomiting, constipation,and hematuria, presenting leukocytosis and increased serum urea. Two abdominal ultrasounds were performed 30 days apart and the third at 3 months. Results:Inthe first ultrasound there was hydronephrosis in the right kidney and dilation of the ureter and microlithiasis in the urinary bladder. The animalhad already been treated with antibiotic therapy and did not improve. Given these characteristics, Cantharis Vesicatoria30cH was administered, there was no more hematuria and when the drug was discontinued, the symptom returned. After 30 days of startinghomeopathic treatment, we repeated the ultrasound which showed 2 kidney stones, and a urinary bladder with cystitis associated with sandy lithiasis. BerberisVulgaris30cH was then administered for 15 days, after which both drugs were discontinued and theanimal remained asymptomatic. After 3 months the ultrasound was repeated which showed 2 kidney stones, Causticum6cH was inserted for 14 days to dissolvekidney stones, thus preventing the return of the initial symptoms. Conclusion:the treatment was beneficial for the patient, who was asymptomatic after the use of Causticum.Considering the natural history of the disease in cats and the high chance of recurrence of the disease, the recommendation was to monitor the organs through an annual ultrasound examination, in addition to encouraging water intake.

Risk factors for progression of Urolith Associated with Obstructive Urosepsis to severe sepsis or septic shock.

INTRODUCTION: To analyze the risk factors for progression of urolith associated with obstructive urosepsis to severe sepsis or septic shock, we had done the retrospective cross-sectional study, which would facilitate the early identification of high-risk patients. MATERIALS AND METHODS: Datas were retrospectively reviewed from 160 patients, suffering from obstructive urosepsis associated with urolith between December 2013 and December 2019. There were 49 patients complicating by severe sepsis (severe sepsis group), 12 patients complicating by septic shock (septic shock group), and 99 patients without progressing to severe sepsis or septic shock (sepsis group). The data covered age, gender, BMI (body mass index), time interval from ED (emergency department) to admission, WBC count (white blood cell count), NLR (neutrophil/lymphocyte ratio), HGB (hemoglobin), etc. Datas were analyzed by univariate analyses and multivariate logistic regression analysis. The corresponding nomogram prediction model was drawn according to the regression coefficients. RESULTS: Univariate analysis showed that the differences of age, the time interval from ED to admission, history of diabetes mellitus, history of CKI (chronic kidney disease), NLR, HGB, platelet count, TBil (total bilirubin), SCr (serum creatinine), ALB (albumin), PT (prothrombin time), APTT (activated partial thromboplastin time), INR (international normalized ratio), PCT (procalcitonin), and positive rate of pathogens in blood culture were statistically significant (P < 0.05). Multivariatelogistic regression analysis showed that age, SCr, and history of CKI were independent risk factors for progression to severe sepsis, or septic shock (P < 0.05). CONCLUSIONS: Aged ≥ 65 years, SCr ≥ 248 mol/L, and history of CKI were independent risk factors for progression of urolith associated with obstructive urosepsis to severe sepsis or septic shock. We need to pay more attention to these aspects, when coming across the patients with urolithic sepsis.

Multiple variants in XDH and MOCOS underlie xanthine urolithiasis in dogs.

Hereditary xanthinuria is a rare autosomal recessive disease caused by missense and loss of function variants in the xanthine dehydrogenase (XDH) or molybdenum cofactor sulfurase (MOCOS) genes. The aim of this study was to uncover variants underlying risk for xanthinuria in dogs. Affected dogs included two Manchester Terriers, three Cavalier King Charles Spaniels, an English Cocker Spaniel, a Dachshund, and a mixed-breed dog. Four putative causal variants were discovered: an XDH c.654G > A splice site variant that results in skipping of exon 8 (mixed-breed dog), a MOCOS c.232G > T splice site variant that results in skipping of exon 2 (Manchester Terriers), a MOCOS p.Leu46Pro missense variant (Dachshund), and a MOCOS p.Ala128Glyfs*30 frameshift variant that results in a premature stop codon (Cavalier King Charles Spaniels and English Cocker Spaniel). The two splice site variants suggest that the regions skipped are critical to the respective enzyme function, though protein misfolding is an alternative theory for loss of function. The MOCOS p.Leu46Pro variant has not been previously reported in human or other animal cases and provides novel data supporting this residue as critical to MOCOS function. All variants were present in the homozygous state in affected dogs, indicating an autosomal recessive mode of inheritance. Allele frequencies of these variants in breed-specific populations ranged from 0 to 0.18. In conclusion, multiple diverse variants appear to be responsible for hereditary xanthinuria in dogs.

Urolithiasis in a captive Siberian chipmunk (Eutamias sibiricus).

This clinical case describes struvite urolithiasis in a pet chipmunk. Physical examination revealed the presence of two ovoid palpable masses in the caudal part of the abdomen, which were later confirmed by radiography as urinary bladder stone. The animal underwent ventral midline laparotomy and uroliths were successfully removed. Uroliths analysis revealed the presence of struvite and bacteriology showed the presence of Proteus mirabilis. Little is known about aetiology and incidence of urolithiasis in chipmunks. Client education about husbandry, dietary needs, and animal behaviour is necessary, especially when dealing with less commonly kept exotic companion mammals. This is the first report of struvite urolithiasis in a pet chipmunk.

Effects of crude protein and sodium intake on water turnover in cats fed extruded diets.

The comprehension of strategies to increase urine production may be important, especially in kibble diets to prevent urolithiasis in cats. The effects of increasing amounts of crude protein (CP) and sodium on the water turnover of cats were evaluated using the water balance (WB) method and the deuterium dilution technique. The study followed a randomized block design, with three blocks of eight cats, two cats per food type in each block, and six cats per food. Four extruded diets with different amounts of CP and sodium were evaluated (on DM basis): 28% CP and 0.58% sodium; 39% CP and 0.64% sodium; 52% CP and 0.76% sodium; and 64% CP and 0.87% sodium. Cats were individually housed in cages for 8 days to measure WB, urea excretion, and faecal and urine characteristics. Deuterium oxide was used to evaluate water turnover, and during the period cats were housed in a collective cattery. The data were analysed by an F test, and the means were compared by polynomial contrasts. The ɑ level of significance was set at 0.05. The methods were compared by Pearson correlation, and Bland and Altman analysis. The increase in the CP content elevated linearly the renal excretion of urea (p < .001), and, together with the higher sodium intake, elevated the renal solute load, which resulted in a linear increase in urine production and water intake (p < .01). The urine density, metabolic water, and faecal and insensible water losses did not differ (p > .05). The water flux increased linearly when using the deuterium method (p < .001), but the obtained values were 20.85 ± 11.11 ml/cat/day higher than those verified using the WB method (p = .001). Higher CP and sodium amounts in dry diets increased the urine production and water consumption of cats, and this can be explored as a possible option to increase urination.

Sheep urinary tract architecture is not affected by acute urethral obstruction / A arquitetura do trato urinário de ovinos não é afetada pela obstrução uretral aguda

Urolithiasis affects the urinary tract of small ruminants, thereby requiring the animal to prematurely terminate breeding. Morphometric study of organs can be used as a diagnostic method. Thus, this study aimed to describe the macroscopic, histopathological, and histomorphometric changes in the urinary tract of sheep with urolithiasis. For this purpose, 14 healthy male Santa Inês sheep, approximately 90 days old, were studied and fed an experimental diet. After the development of urolithiasis, the animals were reorganized into two groups, D1 (without urolithiasis) and D2 (with urolithiasis) for comparative data analysis. Sheep were necropsied to evaluate the pathological changes, followed by macroscopic morphometric analysis, and the histopathological and histomorphometric characteristics were described. Urethral necrosis and a full urinary bladder were observed in all animals that developed the disease. The comparison between sheep with and without urolithiasis showed no significant difference (P < 0.05) in the evaluated macroscopic morphometric variables, except for the right ureter width. Regarding the histopathological evaluation, multifocal areas of mild to moderate congestion within the glomerular tufts and protein in the tubular lumen of the kidneys were observed. In the liver, mild to moderate fatty degeneration was noted in the centrolobular regions, and an ulcerated focal area in the bladder mucosa was observed in only one animal. The present study demonstrated that the formulated diet was effective in inducing clinical disease. In acute obstructive urolithiasis in sheep tissue, lesions in the liver and urinary tract were observed, although there were no significant histomorphometric changes.(AU)

Urolitíase acomete o trato urinário de pequenos ruminantes causando a saída prematura de animais destinados à reprodução. O estudo morfométrico dos órgãos pode ser empregado como método de auxílio diagnóstico. Assim, este estudo objetivou descrever as alterações macroscópicas, histopatológicas e histomorfométricas do trato urinário de ovinos com urolitíase. Com esse fim, foram utilizados 14 ovinos hígidos, machos, da raça Santa Inês com idade aproximada de 90 dias, que receberam dieta experimental. Após o desenvolvimento da urolitíase os animais foram reorganizados em dois grupos experimentais distintos D1 (sem urolitíase) e D2 (com urolitíase) para a análise comparada dos dados. Os ovinos foram necropsiados para descrição das alterações patológicas, seguindo-se a análise morfométrica macroscópica e descrição quanto as características histopatológicas e histomorfométricas. Necrose de processo uretral e bexiga urinária repleta foram observados em todos os animais que desenvolveram a doença. Na comparação entre os ovinos com e sem urolitíase não houve diferença significativa (P < 0,05) nas variáveis morfométricas macroscópicas avaliadas, a exceção da largura do ureter direito. Quanto à avaliação histopatológica, foram observadas áreas multifocais de discreta a moderada congestão dos tufos glomerulares e proteína no lúmen tubular nos rins. No fígado, observou-se nas regiões centrolobulares, discreta a moderada degeneração gordurosa e apenas em um animal foi observada, macro e microscopicamente, área focal ulcerada na mucosa da bexiga. Os achados da presente pesquisa demonstraram que a dieta formulada foi eficaz na indução da doença clínica. Na urolitíase obstrutiva aguda em ovinos, lesões teciduais em fígado e trato urinário são observadas, mas não há alterações histomorfométricas significativas.(AU)

Feline abdominal ultrasonography: What's normal? What's abnormal? Renal pelvis, ureters and urinary bladder.

PRACTICAL RELEVANCE: Abdominal ultrasound plays a vital role in the diagnostic work-up of many cats presenting to general and specialist practitioners. Ultrasound examination of the urinary tract provides important information useful in the investigation of several conditions including ureteral obstruction and cystitis. CLINICAL CHALLENGES: Despite ultrasonography being a commonly used modality, many practitioners are not comfortable performing an ultrasound examination or interpreting the resulting images. Even for the experienced ultrasonographer, differentiating between incidental findings, such as lipid droplets in the bladder, and pathological changes can be challenging. AIM: This review, part of an occasional series on feline abdominal ultrasonography, discusses the ultrasonographic examination of the normal and diseased renal pelvis, ureters and urinary bladder. Aimed at general practitioners who wish to improve their knowledge of and confidence in feline abdominal ultrasound, this review is accompanied by high-resolution images and videos available online as supplementary material. Ultrasound examination of the kidneys and perinephric space was discussed in an article published in May 2020. EQUIPMENT: Ultrasound facilities are readily available to most practitioners, although the use of ultrasonography as a diagnostic tool is highly dependent on operator experience. EVIDENCE BASE: Information provided in this article is drawn from the published literature and the author's own clinical experience.

High occurrence rate of xanthomatosis and nephrocalcinosis in aquarium-housed Atlantic wolffish Anarhichas lupus and spotted wolffish A. minor.

The Atlantic wolffish (AW) and the spotted wolffish (SW) are long-lived fish found in the North Atlantic and Arctic oceans and are respectively classified as special concern and threatened species, mainly due to fisheries bycatch. To better understand health issues associated with the care of these species in public aquaria, reports from all necropsies performed in 2 zoological institutions between 2009 and 2019 were reviewed (31 AW and 8 SW). These wolffish were fed with a similar fish-based diet and kept in multi-species exhibits with comparable environmental parameters. The most frequent necropsy findings were the presence of xanthomas (AW: 41.9%; SW: 75.0%), nephrocalcinosis (AW: 42.9%; SW: 75.0%) and urocystoliths (AW: 6.5%; SW: 62.5%). Xanthomas were mostly located at the base of pectoral fins and were characterized by extensive granulomatous inflammation centered on accumulations of partly mineralized degenerate fatty material, mainly composed of cholesterol crystals. Nephrocalcinosis was characterized by the deposition of calcium salts within the renal tubules and was commonly associated with tubular necrosis. The aquarium-housed wolffish were fed a coldwater fish-based diet. However, the natural diet of wolffish is composed mostly of invertebrates such as urchins and crustaceans. Differences in nutrient composition between these diets, such as lipid and mineral content, may have contributed to the development of xanthomatosis, nephrocalcinosis and urocystolithiasis in wolffish housed in these institutions.

Cistotomía asistida por laparoscopia en un caballo de Paso Fino con cálculo vesical / Laparoscopic assisted cystotomy in a Paso Fino horse with a cystic calculus / Cistotomia assistida por laparoscopia em um cavalo de Paso Fino com cálculo na bexiga

Resumen La urolitiasis es la presencia de concreciones minerales de los cristales de orina en las vías urinarias. En los equinos esta patología tiene una prevalencia baja (0,4% a 0,5%), su presentación se da en riñones y vejiga generalmente, siendo ésta última el sitio de mayor frecuencia. Los urolitos más reportados en caballos se encuentran compuestos por carbonato de calcio. El diagnóstico se realiza comúnmente relacionando los hallazgos del examen clínico junto con la ecografía. Para el tratamiento se realiza abordaje quirúrgico. Un equino macho castrado, criollo colombiano, de doce años y un peso de 350 kg fue remitido para interconsulta por la presentación histórica de dos meses de pigmenturia y disuria, a la palpación transrectal se encontró una estructura redonda y compacta de aproximadamente 7 cm de diámetro ubicada en la vejiga, lo cual fue confirmado mediante ecografía vesical y cistoscopia, a su vez, se realizó citología del sedimento urinario. El abordaje terapéutico se hizo mediante manejo médico y quirúrgico por la técnica de cistotomía asistida por laparoscopia. El objetivo de este artículo es describir el primer reporte de caso de un urolito y de una cistotomía asistida por laparoscopia en un Caballo Criollo Colombiano.

Abstract Urolithiasis is the presence of mineral concretions or urine crystals at the urinary tract. In horses, urolithiasis has a relatively low prevalence (​0.4% to 0.5%), its presentation occurs at the level of the kidneys and the urinary bladder, the last one is the site of the greatest presentation. Most of the uroliths in horses are constituted for calcium carbonate. The diagnosis is commonly made by relating the findings of the clinical examination along with the ultrasound. Surgical resolution is the election for treatment. The patient was a 350 kg, twelve years old Colombian creole gelding referred with historical presentation of two months of pigmenturia and dysuria, to the transrectal palpation a round structure of approximately 7 cm of diameter was located in the urinary bladder, which was confirmed by ultrasound and cystoscopy, in addition, cytology of the urinary sediment was performed. The therapeutic approach was made with medical and surgical management by assisted laparoscopic approach. The aim of this case report is to describe for the first time a case of urolithiasis and its resolution by assisted laparoscopy in a Colombian Creole Horse.

Resumo A urolitíase é a presença de concreções minerais macroscópicas de cristais de urina no trato urinário. A prevalência desta afeccão em equinos é relativamente baixa (0,4% a 0,5%), geralmente acomete rins e vesicula urinária, sendo esta última o principal local de apresentação. A maior porcentagem dos urólitos de equinos é composta de carbonato de cálcio. O diagnóstico é comumente feito pela associacão dos achados do exame clínico e ultrassonográficos. A abordargem cirurgica é normalmente o tratamento de escolha, sendo realizada por meio de laparocistotomia. O paciente deste relato era um cavalo crioulo colombiano, com doze anos e pesando 350 kg, que foi encaminhado com histórico de dois meses de pigmenturia e disúria. A palpação transretal revelou uma estrutura esférica de cerca de 7 cm de diâmetro dentro bexiga, o foi confirmado por ultrassonografia e cistoscopia, seguido por citologia do sedimento urinário . A abordagem terapêutica foi realizada com manejo médico e cirúrgico, que consistiu de técnica de cistotomia assistida por videolaparoscopia. O objetivo deste relato de caso é descrever o primeiro caso de um urólito e uma cistotomia assistida por laparoscopia em um Cavalo Crioulo Colombiano.

Effect of a commercial anionic dietary supplement on urinary pH and concentrations of electrolytes and pH in blood of horses.

Aims: To compare urine urinary pH, blood pH and concentration of electrolytes in blood of healthy horses fed an anionic salt supplement to achieve diets with a dietary cation-anion difference (DCAD) of -40 or 0 mEq/kg DM, with horses a fed a diet with a DCAD of 85 mEq/kg DM.Methods: Eight healthy horses received each of three diets in a randomised crossover design. Diets consisted of grass hay and concentrate feed, with a varying amount of an anionic supplement to achieve a DCAD of 85 (control), 0 or -40 mEq/kg DM. They were fed for 14 days each with a washout period of 7 days between. Urine pH was measured daily and blood samples were collected on Days 0, 7 and 14 of each study period for the measurement of pH and concentration of electrolytes.Results: Four horses voluntarily consumed the anionic supplement with their feed, but four horses required oral supplement administration via dose syringe. During the study period mean urine pH was lower in horses fed diets with a DCAD of 0 (6.91; SD 0.04) and -40 (6.83; SD 0.04) mEq/kg DM compared to the control diet (7.30; SD 0.04). Compared with horses fed the control diet, mean urine pH was lower in horses fed the 0 and -40 mEq/kg DM diets on Days 1-12 and 14 (p < 0.05) of the study period. On Day 13 it was only lower in horses fed the -40 mEq/kg DM diet (p < 0.01). Urine pH was similar for horses fed the 0 and -40 mEq/kg DM diets (p = 0.151). The DCAD of the diet had no effect on blood pH, ionised Ca or anion gap. Mean concentrations of bicarbonate in blood were affected by diet (p = 0.049); they were lower when horses were fed the 0 mEq/kg diet relative to the control diet on Day 14.Conclusions and clinical relevance: The anionic supplement reduced urine pH in horses fed diets with a DCAD of 0 or -40 mEq/kg DM compared with 85 mEq/kg DM. However as urinary pH did not fall below pH 6.5, the pH below which calcium carbonate uroliths do not form, this reduction in urine pH is unlikely to be clinically significant. The supplement was variably palatable and showed minimal promise as an effective urinary acidifier at the doses administered in this study.

Hereditary xanthinuria in a goat.

A 2-year-old mixed breed goat was presented for a 1-day history of anorexia and 1 week of weight loss. Serum biochemistry disclosed severe azotemia. Abdominal ultrasound examination showed decreased renal corticomedullary distinction, poor visualization of the renal pelves, and dilated ureters. On necropsy, the kidneys were small, the pelves were dilated, and the medulla was partially effaced by variably sized yellow nephroliths. Histologically, cortical and medullary tubules were distended by yellow-brown, multilayered crystals. Stone composition was 100% xanthine. Exonic sequencing of xanthine dehydrogenase (XDH) and molybdenum cofactor sulfurase (MOCOS) identified 2 putative pathogenic variants: a heterozygous XDH p.Leu128Pro variant and a homozygous MOCOS p.Asp303Gly variant. Variant frequencies were determined in 7 herd mates, 12 goats undergoing necropsy, and 443 goats from genome databases. The XDH variant was not present in any of these 462 goats. The MOCOS variant allele frequency was 0.03 overall, with 3 homozygotes detected. Hereditary xanthinuria is a recessive disorder in other species, but the XDH variant could be causal if the case goat is a compound heterozygote harboring a second variant in a regulatory region not analyzed or if the combination of the XDH and MOCOS variants together abolish XDH activity. Alternatively, the MOCOS variant alone could be causal despite the presence of other homozygotes, because hereditary xanthinuria in humans often is asymptomatic. Ours is the first report describing the clinical presentation and pathology associated with xanthine urolithiasis in a goat. The data support hereditary xanthinuria, but functional studies are needed to conclusively determine the causal variant(s).

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

OBJECTIVES: The study objectives were to determine if the method of water presentation (still [S], circulating [C] or free-falling [FF] bowl systems) influences daily water consumption in cats in a controlled environment, and whether differences in water intake affect urine relative super saturation (RSS) for calcium oxalate and struvite, urine specific gravity (USG), urine osmolality (Uosmol) and urine volume. METHODS: Sixteen healthy laboratory cats fed a dry diet were individually housed with urine collection systems. Each cat underwent a randomized 2 week crossover period with all bowl systems, allowing a 1 week acclimation period between each crossover. Water intake was measured daily by bowl weight, accounting for spillage and evaporation. USG and urine volume were measured daily, whereas other urinary parameters were measured at various time points throughout each 14 day crossover period. RESULTS: Fourteen cats completed the study. Average daily water intake (ml/kg/day), urine volume, USG and urine RSS for struvite and calcium oxalate were not significantly different between water bowls. Uosmol was significantly higher in C compared with S and FF bowl systems (P = 0.009 for both). Three individual cats demonstrated a significant water bowl preference (Cat 4: C >S, P = 0.039; Cat 10: FF >C, P = 0.005; Cat 11: S >C, P = 0.037). CONCLUSIONS AND RELEVANCE: Overall, water bowl type had no appreciable effect on water intake. Uosmol was the only urinary parameter found to be significantly different, and was higher for the C bowl. The implication of this is unknown, considering water intake did not differ significantly between bowls. Alternative methods to increase water intake should be implemented beyond providing unique water bowls in patients where augmented water intake would be beneficial for disease management.