Surgery of Obstructive Urolithiasis in Ruminants

[Uroperitoneum in a heifer]

Uroperitoneum is a rarely documented finding in heifers. More frequently uroperitoneum is described in male youngstock suffering from obstructive urolithiasis, or abscesses of the urachus. This report describes a case of uroperitoneum most likely as a result of a traumatic rupture of the urinary bladder in an 8.5 months old heifer. The animal was presented with a severely dilated abdomen and an undulating wave was evident upon palpation. The heifer exhibited physiologic urination. Additionally, left displacement of the abomasum was evident. In consequence to findings of the ultrasonographic examination and abdominocentesis, diagnostic laparotomy was performed. Urine was evacuated from the abdominal cavity in fractions and the damaged cranial pole of the urinary bladder was excised followed by the suture of the urinary bladder. The abomasum was replaced in its physiologic position and an omentopexy was performed. The heifer was discharged from hospital and was still in the herd 5 years after discharge.

Hematological differentiation of bladder rupture and complete/partial urethral obstruction in castrated Hanwoo (Korean indigenous cattle) with urolithiasis

This case report describes the hematological and radiological examination of urinary bladder rupture and complete urethral obstruction. associated with urolithiasis in Hanwoo. Hyponatremia, hypochloremia, azotemia, and hyperglycemia were observed in both urethral obstruction and urinary bladder rupture. However, cattle with urethral obstruction showed hyperkalemia and mild hyperglycemia, whereas cattle with bladder rupture showed marked hyperglycemia and normal potassium levels. In ultrasonography, the urethral obstruction showed a dilated bladder with a thick bladder wall. In contrast to previous literature, in this study, severe electrolyte changes such as severe hyponatremia, hypochloremia, and hyperkalemia occurred in a case of complete urethral obstruction.

Crystallurical profile in sheep after ammonium chloride supplementation

ABSTRACT Although urinary crystals are habitual components, urolithiasis formation is always preceded by these concretions. We aimed to identify the change in the crystalline profile in sheep supplemented with ammonium chloride. Twenty-five male sheep aged three months, feedlot and randomly distributed into three groups were used: Control Group (CG) n = 5 did not receive Ammonium Chloride; G200 Group (n=10) (200mg/kg) of Ammonium Chloride for 56 consecutive days; G500 Group (n=10) (500mg/kg) of Ammonium Chloride for 56 consecutive days, administered daily orally. Sampling times and clinical evaluation were performed at seven days, with M0 (immediately before Ammonium Chloride), M1 (seven days after) until M8, totaling 70 days of feedlot. Urine samples were performed to identify the presence, type, and quantity of crystals. There was an increase in crystalluria in all groups in relation to time due to dietary influence, mainly in the CG, which presented more crystals of amorphous calcium phosphate and calcium oxalate. In addition, the G500 Group presented a higher presence of urate/uric acid crystals after urinary acidification, which are closely related to urinary pH.

Präpubische Urethrostomie bei einem Wiesenauer Minischwein mit Urolithiasis

Ein 10-jähriges kastriertes, männliches Minischwein wurde aufgrund eines Tenesmus vesicae mit Anurie vorgestellt. Begleitsymptom war eine Tachypnoe. Röntgenologisch waren zahlreiche Harnsteine in Blase und Urethra nachweisbar. Über die Harnröhre konnte nicht katheterisiert werden, sodass eine Notfallzystostomie mit Einlegen eines Ballonkatheters durchgeführt wurde. Trotz Blasenspülung gelang es nicht die Harnröhrensteine so auszuspülen. Deswegen wurde ein präpubisches Urethrostoma angelegt. Das Tier erholte sich vollständig und setzt seither problemlos Urin über die urethrale Fistel ab. Prophylaktische Maßnahmen der Urolithiasis beinhalten unter anderem eine ausreichende Wasseraufnahme, eine ausgewogene Fütterung und balancierte Futterzusammensetzung sowie die Gewährleistung eines physiologischen Urin-pH-Werts.

Urethral Urolithiasis in Male Cattle Treated Using Pneumatic Lithotripsy

One of the most important problems encountered in cattle breeding is urethral urolithiasis. Urolithiasis can be treated using various methods, but they all carry risks. Thus, a continuous search is being carried out for alternatives in this field. This study aimed to treat urethral urolithiasis in male cattle using pneumatic lithotripsy, a minimally invasive method. The urethra and penile tissues of 20 male cattle of different ages and breeds were obtained from slaughterhouse materials and measured before determining the probe diameters and lengths. The study included 9 male cattle (2 Simmental hybrids, 1 Zavot hybrid, 1 Brown, and 5 Simmental), between 4 months and 2 years of age, diagnosed with urethral urolithiasis. A modified lithotripsy apparatus was used for the pneumatic disintegration of urinary stones. The localization of urinary stones in the urethra was determined by palpation and catheterization. After laying the animal in a lateral position, a lithotripsy probe of appropriate length and diameter was advanced from the external urethral orifice to the site of localization. Once the probe came into contact with the stone, a vibration of 125 bar was applied until the stone was broken. The probe was removed, and the urethral channel was washed with 0.1% iodine solution to remove the shredded urethral stones. Uncomplicated recovery was achieved in all treated cases. In conclusion, pneumatic lithotripsy provided successful results in treating urolithiasis and can be used as an alternative surgical method in cattle. Moreover, the low cost is an additional advantage to breeders.

Assessment of preoperative and postoperative l-lactatemia and clinical outcomes in goats undergoing tube cystostomy: A retrospective study of 34 cases (2015-2020)

BACKGROUND

Urolithiasis in small ruminants has a poor long-term prognosis, and long-term clinical outcomes are variable and unpredictable.

OBJECTIVES

To assess the accuracy of preoperative and postoperative blood l-lactate concentrations in predicting a negative outcome in goats undergoing tube cystostomy.

ANIMALS

Thirty-four male goats undergoing tube cystostomy.

METHODS

Retrospective study. Medical records of goats undergoing tube cystostomy from 2015 to 2020 were reviewed. Clinical variables recorded included signalment, procedures before surgery, urolith location and type, duration of hospitalization, and heart rate. PCV, plasma total protein, potassium, preoperative and postoperative blood l-lactate concentrations, preoperative and postoperative creatinine concentrations, and relative changes in blood l-lactate and creatinine concentrations over time were measured using heparinized blood. A negative outcome was defined as death or euthanasia from urolithiasis complications at 6 months after discharge. Negative outcomes as a function of independent clinical variables were evaluated using χ² or Fisher's exact tests, and multivariate logistic regression. P < .05 was considered significant.

RESULTS

Median (95% confidence interval) preoperative, postoperative, and the relative change over time of blood l-lactate concentrations were 3.3 mmol/L (2.2, 4.8), 1.0 mmol/L (0.7, 1.3), and 0.4 mmol/L (-3.5, 3.2), respectively. Preoperative (P = 1), postoperative (P = .14), and the relative change over time (P = .63) of blood l-lactate concentrations were not significant predictors of a negative outcome. Furthermore, all other clinical variables measured were not significant predictors of a negative outcome (P > .05).

CONCLUSIONS AND CLINICAL IMPORTANCE

Veterinarians should advise clients that clinical outcomes after tube cystostomy in goats are likely unpredictable.

Effect of magnesium ammonium phosphate on the expression of adhesion molecules in sheep renal tubular epithelial cells

Adhesion molecules play an important role in urinary calculus formation. The expressions of adhesion molecules in renal tubular has been reported in some animals. However, the role of adhesion molecules in the process of sheep urinary calculus formation is still unclear. The magnesium ammonium phosphate (MAP) is the main component of sheep urinary calculus. In this paper, the sheep renal tubular epithelial cells (RTECs) were isolated and treated with MAP, the expressions of osteopontin (OPN), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and apoptosis-related indicators caspase-3, Bcl-2 and Bax in RTECs were observed, the viability of RTECs was detected by Cell Counting Kit-8 (CCK-8). The levels of superoxide dismutase (SOD) and malondialdehyde (MDA), and the expressions of inflammatory factors Interleukin-6 (IL-6), Interleukin-1 (IL-1), Interleukin-17 (IL-17) and tumor necrosis factor-α (TNF-α) were measured by enzyme-linked immunosorbent (ELISA). The histopathological observation of kidney in urolithiasis sheep was made. The results showed that MAP could reduce the viability and SOD activity, enhance the activity of MDA significantly and promote the expressions of IL-1, IL-6, IL-17 and TNF-α of RTECs. By western blot and qPCR methods, the expressions of ICAM-1, VCAM-1 and OPN increased in 48 h. In addition, the expression of caspase-3 increased significantly and the ratio of Bcl-2/Bax reduced with exposure to MAP. The renal tissue structure was seriously damaged, the RTECs in urolithiasis sheep were degenerative and necrotic.

Management of Reproductive Diseases in Male Small Ruminants

Reproductive tract diseases can be a significant cause of subfertility or infertility in male small ruminants. Affected males can usually be identified early by performing routine serologic screening and yearly breeding soundness examinations. Early diagnosis will either maximize treatment success or expedite culling decisions. Once clinical signs of diseases develop, prognosis for breeding ability declines. Veterinary practitioners should used ancillary diagnostic techniques, such as ultrasound examination and laboratory testing to acquire a diagnosis and determine prognosis of reproductive lesions. Some diseases (eg, brucellosis) should be ruled out immediately to cull affected animals and minimize transmission within the herd.

Management of Urologic Conditions in Small Ruminants

Small ruminants frequently experience urologic conditions, such as obstructive urolithiasis, posthitis, vulvitis, and urinary tract infections. Urologic conditions are more common in male small ruminants, especially castrated males, primarily due to their anatomy. Traditionally, urologic conditions warranted culling from the herd without significant efforts in treatment. However, more goats and sheep are now being kept as pets. Small ruminant owners have strong emotional attachments to their animals and are more likely to seek treatment of medical disorders, including urologic conditions. Surgical or medical treatments are available. Conditions also may be avoided through hydration, diet, hygiene, and other means.

Use of tube cystostomy in the surgical management of obstructive urolithiasis in a Bactrian camel

CASE DESCRIPTION

A 6-year-old castrated male Bactrian camel was evaluated because of a 14hour history of oliguria and stranguria that progressed to anuria.

CLINICAL FINDINGS

Perineal urethral pulsations and intermittent tail flagging with no accompanying urination were observed. Ultrasonography of the urethra revealed multiple hyperechoic foci with shadowing artifact indicative of calculi present in the penile urethra distal to the sigmoid flexure. Rectal palpation revealed a pulsating hard urethra and intact distended urinary bladder. Further clinical examination was not possible because of challenges associated with handling the camel.

TREATMENT AND OUTCOME

Urethral catheterization through a perineal urethral incision failed to achieve urinary bladder decompression. Tube cystostomy was performed to prevent bladder rupture. Urethrocystography performed 3 days after surgery revealed a urethral rupture at the level of the prepuce. Five weeks after surgery, the camel could urinate a steady stream via the urethrotomy site. Seven weeks after surgery, the cystostomy tube was removed, and the urethrotomy site was modified to provide a permanent urethral opening via perineal urethrostomy. During 6 years of subsequent periodic follow-up by telephone, the owner reported that the camel continued to do well and urinate through the revised opening.

CLINICAL RELEVANCE

To the authors' knowledge, this is the first detailed description of a tube cystostomy in an adult camel with obstructive urolithiasis that includes information on the patient's long-term outcome. This technique was a viable option in the surgical management of obstructive urolithiasis in this camel and may be useful for other large camelids as well.

A pilot study to assess the feasibility of endoscopic placement of a transurethral urinary balloon catheter in male sheep cadavers

Surgery of obstructive urolithiasis in small ruminants is often unsatisfactory due to postoperative development of strictures. The present study aimed to establish an endoscopic technique for the placement of a transurethral urinary catheter into the bladder of rams. This catheter was used as a removable stent-like drainage. The procedure was performed in three sheep rams that were euthanized and placed for surgery in 45° Trendelenburg position. In one ram, cystotomy was performed via right paramedian laparotomy. A 3 mm flexible fiberscope was introduced into the urinary bladder and advanced via urethra to the tip of the penis. Placing a guide wire through the endoscopic working channel into the urethra enabled the retrograde insertion of a transurethral urinary catheter into the bladder. In two rams, retrograde insertion of a fiberscope was performed. Again, a guidewire was used to insert a balloon catheter into the bladder. Paramedian right laparotomy was performed to ascertain the correct position of the balloon. Both techniques, antero- and retrograde endoscopy, were possible and could be successfully performed. Mucous membranes and urinary microliths were easily observed. Repeated advancing of the endoscope or the catheter resulted in marked damage of the mucous membranes. The patency of the urethra may be restored by means of endoscopic placement of a transurethral catheter in male small ruminants. The applicability and clinical outcome of this procedure as well as the effects on stricture formation should be further examined with controlled clinical studies.

Outcome and complications in goats treated by perineal urethrostomy for obstructive urolithiasis: 25 cases (2010-2017)

Background

Obstructive urolithiasis commonly affects male goats. Perineal urethrostomy (PU) can be a permanent treatment option but is generally considered undesirable because of the risk of stricture of the urethral stoma. Limited information exists regarding long‐term outcome and complications in goats undergoing PU for treatment of obstructive urolithiasis.

Objectives

To determine short‐term and long‐term outcome and complications in goats undergoing PU for treatment of obstructive urolithiasis.

Animals

Twenty‐five client‐owned goats.

Methods

Multi‐institutional retrospective case series.

Results

Of the 25 goats, 13 (52%) were alive at the time of follow‐up. Mean time from surgery to follow‐up was 34 months (range, 4‐65). Nine goats (36%) died between discharge and follow‐up with a mean survival time of 46 days (range, 5‐120). Cause of death in 7 of 9 (78%) goats was related to urolithiasis. Goats treated by use of a modified proximal perineal urethrostomy (MPPU) were significantly more likely to survive at least 150 days postoperatively (P < .01). The most common postoperative complications were hemorrhage (10/25 [40%]) and surgical site infection (3/25 [12%]). Hemorrhage was significantly associated with MPPU (P < .0001). Stricture of the surgical stoma occurred in 7 of 22 (32%) discharged goats. Mean time to stricture was 65 days (range, 10‐240).

Conclusions and Clinical Importance

Perineal urethrostomy can provide effective long‐term resolution of obstructive urolithiasis in goats. Re‐obstruction or stricture seems most likely within the 1st 2 months after surgery. MPPU may provide better long‐term results but should be approached cautiously because it can be associated with life‐threatening hemorrhage.

Perineal urethrostomy to treat obstructive urolithiasis in a captive hand-raised steenbok (<i>Raphicerus campestris</i>)

The steenbok (Raphicerus campestris) is a small antelope of the family Bovidae native to the African continent. Urolithiasis, the formation of urinary calculi in the urinary tract, can be caused by a variety of factors such as diet, dehydration, infection and anatomical predisposition. Urolithiasis, with uroliths identified as magnesium calcium phosphate carbonate in composition, was diagnosed in a hand-reared 5-month-old steenbok. Perineal urethrostomy was performed as a component of the broad treatment regime that included fluid therapy, antibiotic and anti-inflammatory treatment. However, the animal died 4 days later as a result of systemic hypoxia and energy depletion because of stress and cachexia. The challenges of post-surgical treatment, the importance of positive energy balance in small ruminants under stressful circumstances, as well as the role of diet of hand-reared antelope in predisposition to urolith formation are highlighted.

Mineral Composition of Uroliths Obtained from Sheep and Goats with Obstructive Urolithiasis

Background

Knowledge of the mineral composition of the causative urolith is important to develop preventative strategies. Advances in analytic techniques have led to detection of urolith components not previously recognized.

Hypothesis/Objectives

The objectives of this study were to characterize uroliths in sheep and goats structurally and clinically. We hypothesized that amorphous magnesium calcium phosphate (AMCP) would be a naturally occurring urolith type in sheep and goats.

Animals

Forty‐nine sheep and goats presenting for obstructive urolithiasis from June 15, 2014 through June 14, 2016 were reviewed along with the demographic data of all small ruminants admitted during that same period.

Methods

Medical records were reviewed for demographic and historical data, and 36 uroliths obtained from these cases during diagnostic or therapeutic procedures were analyzed by infrared spectroscopy to determine chemical composition.

Results

AMCP is a naturally occurring urolith type in obstructed male sheep and goats and was the most common urolith type in this study, where it occurred as a majority component with struvite (39% of uroliths) or as a pure component (11%). Pure struvite was found in 1 urolith (2%). Calcium carbonate was the second most frequent urolith with 31% of uroliths being pure calcium carbonate.

Conclusions and Clinical Importance

This study demonstrates that uroliths, which appear consistent with struvite, could actually be calcium‐containing AMCP. Urolith analysis is critical in determining mineral content of uroliths to guide dietary recommendations for prevention.

An alternative surgical approach to treatment of obstructive urolithiasis in a ram

Urolithiasis is defined as calculi formation into the urinary tract. The aetiology is related to mineral imbalance in the diet and in most cases, successful treatment is achieved only through surgical procedures. Furthermore, the breeding ability could be impaired. This report describes the technique of cranial penile urethrostomy associated with partial penectomy performed for the treatment of urolithiasis in a ram. Although limited to cranial obstructions, this technique is low-costs, only the penile tissues are accessed, general anaesthesia is not required and breeding ability may be preserved.

Surgical Management of Common Disorders of Feedlot Calves

Procedures to improve animal and handler safety, shape production parameters, and directly address the prosperity of individuals in need of assistance are performed routinely. Techniques to accomplish these tasks have been described in many venues. Painful procedures are expected in feedlot practice. Assessing and managing pain and welfare for these procedures has strengthened significantly over the past decade to address increased public concerns and also to support the desires of the operators/managers to progress. Methods to perform common procedures are described, including evidence and techniques for managing the pain and distress while performing them.

Laparoscopic cystostomy in pigs: Technique and comparison with traditional open cystostomy for surgical stress

Cystostomy is a common procedure in veterinary surgery. We describe a technique for laparoscopic cystostomy (LC group; n = 7) in Bama miniature pigs and compare the surgical stress induced by this procedure to open cystostomy (OC group; n = 7). A three-portal approach was used for laparoscopic cystostomy. First, we placed 2 simple interrupted sutures between the ventral body wall and urinary bladder. Then, a purse-string suture was placed in the urinary bladder wall, approximately 1 cm cranially to the two sutures. A stab incision was made at the center of the purse-string suture and a 12-F Foley catheter advanced into the urinary bladder; the suture was then pulled tightly and tied. Again, two interrupted sutures were placed 1 cm cranially to the catheter, between the ventral body wall and the bladder, to establish cystopexy. The extracorporeal portion of the catheter was fixed to the skin by a finger-trap suture. Blood samples were collected to measure the white blood cell count and serum concentrations of cortisol, interleukin-6, and C-reactive protein; follow-up laparoscopy was performed 1 month after the surgery. Laparoscopic cystotomy was successfully performed in all the pigs; the mean operating time was 43 ± 5 min. The levels of the stress markers reflected a lower stress response for LC than OC. Thus, LC appears to be better than OC both in terms of technique and physiological responses elicited, and may be more suitable than OC in the creation of experimental animal models for investigations on urinary diseases and those requiring diversion of urine flow.

Complications associated with perineal urethrotomy in 27 equids

OBJECTIVE

To report the clinical findings, incidence of complications, and outcome associated with perineal urethrotomy in equids.

STUDY DESIGN

Retrospective case series.

ANIMALS

Equids (n = 27).

METHODS

Medical records (January 2000 to December 2010) of equids that had a perineal urethrotomy were reviewed. Data retrieved and evaluated were breed, age, surgical technique, use of general anesthesia, complications, time from surgery to development of complications and their management, and outcome.

RESULTS

Perineal urethrotomy was performed for urolithiasis (n = 22), for treatment of urethral rents (3), severe balanoposthitis (1), and bladder atony caused by equine protozoal myeloencephalitis (1). The incidence of complications was 52%, including recurrence of urolithiasis in 5 (23%) equids. Horses that had postoperative cystoscopy and bladder lavage were significantly less like likely to have recurrence of urolithiasis (P = .039). Of equids that had postoperative indwelling urinary catheters, 75% developed complications.

CONCLUSIONS

Perineal urethrotomy can be an effective for treatment of urolithiasis, hematuria, and urethral trauma. Postoperative cystoscopy and bladder lavage significantly reduced the incidence of postoperative recurrence of urolithiasis.

Effect of supplementation on the performance of grazing Belgian Blue double-muscled heifers

Six experiments were conducted to investigate the effect of a feed supplement on the performance of grazing Belgian Blue double-muscled (BBDM) heifers with an initial weight and age of 195 ± 43 kg and 190 ± 52 days. Treatments included were: Exp. 1: supplementation with beet pulp (BP): 2 kg/day per head v. ad libitum intake; Exp. 2: supplementation ad libitum with BP v. a mixture of BP and soybean meal (SBM; BP/SBM ratio of 80/20; FW (fresh weight) basis); Exp. 3: supplementation with 4 kg/day per head of a mixture of BP/SBM (80/20; FW basis) v. BP/formaldehyde-treated SBM (BP/FSBM); Exp. 4: supplementation with 4 kg/day per head of a mixture with a similar protein content (125 g DVE per kg dry matter (DM)), consisting of 80/20 BP/SBM v. 92/8 BP/FSBM; Exp. 5: supplementation with 3 kg/day per head of a mixture of BP/SBM (80/20; FW basis) v. BP/DDGS (dried distillers grains and solubles; 70/30, FW basis); and Exp. 6: supplementation with 3 kg/day per head of 80/20 BP/SBM v. maize silage (MS) and SBM, on the basis of a similar protein concentration in the DM as the 80/20 BP/SBM supplement, and fed at a similar amount of DM as in the BP/SBM group. Supplementing BP ad libitum did not affect daily gain (0.54 v. 0.48 kg) and partial feed conversion (3.62 kg on average) compared with 2 kg/day. Supplying SBM besides BP increased growth rate compared with BP (0.87 v. 0.62 kg/day; P < 0.001), but partial feed conversion was similar. Supplying FSBM did not affect growth rate and partial feed conversion (P > 0.10), but blood urea levels were reduced by FSBM (P < 0.05). DDGS tended to increase growth rate (0.77 v. 0.59 kg/day; P < 0.10) compared with BP/SBM, without effect on partial feed conversion. Replacing BP by MS did not affect daily gain, but partial feed conversion tended to be higher (3.21 v. 3.60 kg/kg body weight (BW) gain; P = 0.062). Increasing the supplement (80/20 BP/SBM) level from 3 to 4 kg daily, corresponding to 1.02% and 1.18% of the mean BW, respectively, resulted in a tendency (P = 0.121) for an increased growth rate. Grazing BBDM heifers of <1 year of age necessitate extra protein besides an energy supplement to improve their performance. DDGS can replace SBM and BP can be replaced by MS.

Double Muscling in Cattle: Genes, Husbandry, Carcasses and Meat

Molecular biology has enabled the identification of the mechanisms whereby inactive myostatin increases skeletal muscle growth in double-muscled (DM) animals. Myostatin is a secreted growth differentiation factor belonging to the transforming growth factor-β superfamily. Mutations make the myostatin gene inactive, resulting in muscle hypertrophy. The relationship between the different characteristics of DM cattle are defined with possible consequences for livestock husbandry. The extremely high carcass yield of DM animals coincides with a reduction in the size of most vital organs. As a consequence, DM animals may be more susceptible to respiratory disease, urolithiasis, lameness, nutritional stress, heat stress and dystocia, resulting in a lower robustness. Their feed intake capacity is reduced, necessitating a diet with a greater nutrient density. The modified myofiber type is responsible for a lower capillary density, and it induces a more glycolytic metabolism. There are associated changes for the living animal and post-mortem metabolism alterations, requiring appropriate slaughter conditions to maintain a high meat quality. Intramuscular fat content is low, and it is characterized by more unsaturated fatty acids, providing healthier meat for the consumer. It may not always be easy to find a balance between the different disciplines underlying the livestock husbandry of DM animals to realize a good performance and health and meat quality.

Impact of two types of complete pelleted, wild ungulate feeds and two pelleted feed to hay ratios on the development of urolithogenic compounds in meat goats as a model for giraffes

Urolith formation has been documented in giraffes and goats. As research in giraffes poses logistical challenges, 16 buck goats were used as a model. The impact of two commercially available, pelleted feeds used for giraffes, ADF-16 and Wild Herbivore (WH), as well as the impact of alfalfa hay and pellet proportions (20% hay:80% pellets, 80P or 80% hay:20% pellet, 20P) on the formation of urolithogenic precursors in goat urine was accomplished in a 2 × 2 factorial balance study. Complete diets contained 0.60, 0.32, 0.35 and 0.26% phosphorus (P) with calcium:P ratios of 1.60, 4.16, 3.06 and 5.23, for 80P-ADF-16, 20P-ADF-16, 80P-WH and 20P-WH respectively. Total faeces and urine were collected over two 5-day periods to assess N and mineral balance. Fresh urine samples were collected and evaluated microscopically for urolithic crystal content. Urinary nitrogen (N) was lower and N retention was higher in goats fed 80P diets (p < 0.05). Intake of P was greatest for goats fed 80P-ADF-16; however, urinary P excretion and P retention were not affected by treatment. Crystal scores were higher in animals receiving 80P diets (p = 0.08), with crystals being composed predominantly of calcium phosphate. Urine pH was alkaline (>8) for all treatments. Urinary P concentration, a risk factor for urolithiasis, was highest (p ≤ 0.06) in the 80P-ADF-16 treatment (0.38 vs. 0.01, 0.02 and 0.04 mg/dl for 20P-ADF-16, 80P-WH and 20P-WH respectively), reflecting its highest dietary P level. Further investigation is recommended to determine the long-term effects of these diets on urolithogenic compound formation.