Topic:Urinary Health
Urinary health in horses encompasses the study of the equine urinary system, which includes the kidneys, ureters, bladder, and urethra. This system is responsible for filtering blood, removing waste products, and regulating fluid and electrolyte balance. Conditions affecting urinary health can range from infections and obstructions to renal dysfunction and urolithiasis. Monitoring urinary health involves assessing clinical signs, conducting urinalysis, and utilizing imaging techniques. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, physiology, pathophysiology, and clinical management of urinary health issues in horses.
Urinary excretion of pentoxifylline and its metabolites by standardbred mares. The urinary excretion of a sustained-release formulation of pentoxifylline was studied in the horse after the oral administration of 4.0 grams of Trental tablets. Urine samples were collected for 24 hours after dosing and analyzed for pentoxifylline and its metabolites using high-performance liquid chromatography coupled with an ultraviolet detector. Six metabolites of pentoxifylline were identified in horse urine in addition to less than 0.2% of unchanged drug. Concomitant use of gas chromatography/mass spectrometry allowed for the elucidation of the chemical structures of the metabolites. Me...
Transrectal ultrasonography of the caudal portion of abdominal and pelvic cavities in horses. A 5-MHz transducer was used transrectally to image palpable structures in the caudal portion of abdominal and pelvic cavities of 12 horses. In 8 healthy horses, structures scanned transrectally included the left kidney, spleen, urinary bladder, urethra, accessory sex organs in the male, portions of the intestinal tract, caudal portion of the aorta, and iliac arteries, and, in small horses, the cranial mesenteric artery. The transrectal technique was used to evaluate these structures in 4 horses with clinical signs indicating intrapelvic or intra-abdominal disease. Seemingly, transrectal ultras...
Resistance of mammalian red blood cells of different size to hypertonic milieu. 1. The resistance of different mammalian red blood cells (RBCs) to hyperosmotic environments was studied. RBCs of six mammalian species were exposed to 10 increasingly hyperosmotic NaCl solutions for 24 hr at 5 degrees C. 2. The osmolality at which the amount of liberated haemoglobin reached a preset level (e.g. 3-4% of the total haemoglobin) showed a linear correlation with negative slope with RBC volume. This indicates that small RBCs are more resistant to hyperosmotic milieu than large ones. 3. A similar relation can be found from literature data when maximal urinary tonicities are plotted ...
Adjunctive methods of examination of the urogenital tract. Included in this article are descriptions of adjunctive methods of examination of the urogenital tract, including ultrasonography of the kidneys, urinary bladder, ovaries and uterus; endoscopy of the urethra, urinary bladder, and uterus; contrast radiography of the urinary tract; kidney biopsy; and laparoscopy of the abdomen, emphasizing examination of the mare's reproductive tract.
Ectopic ureter managed by unilateral nephrectomy in two female horses. Unilateral ureteral ectopia was diagnosed in three-year-old and 10-month-old fillies exhibiting urinary incontinence since birth. In one case reimplantation of the ureter onto the bladder was planned but considered to be impractical intra-operatively. Unilateral nephrectomy was performed successfully in both cases which alleviated the urinary incontinence. Both horses had normal urinary function postoperatively and became healthy, serviceable animals.
Ureteropyelonephritis in a Friesian mare. A 14-year-old Friesian breeding mare had strangury, depression, inappetence, neutrophilia and uraemia. Its urine had a low specific gravity and contained protein, blood cells and bacteria. Rectal examination showed that both kidneys and ureters were enlarged. Post mortem examination confirmed the diagnosis of pyelonephritis and revealed that small tumours in the vulva were probably the cause of the uropathy.
Nonsurgical management of ruptured urinary bladder in a critically ill foal. A small tear in the urinary bladder of a severely debilitated 4-day-old foal was managed with an indwelling urinary catheter connected to a urine collecting system. Fluid therapy, parenteral nutrition, and antimicrobial agents were used during the initial management of the ruptured bladder. Aseptic technique for catheter care and systemic administration of antimicrobial agents prevented the development of bacterial cystitis. Catheter management required constant monitoring, but the bladder defect was sealed within 5 days. Fungal arthritis caused by Candida tropicalis, immune-mediated anemia, d...
Influence of the autonomic nervous system in the horse urinary bladder. alpha and beta-adrenergic receptors in detrusor muscle and bladder base of horses were investigated by in vitro responses of smooth muscle strips to exogenous agonist and antagonist drugs. Noradrenaline, isoprenaline and salbutamol induced relaxation of detrusor muscle strips which was significantly inhibited by propranolol and butoxamine suggesting that the response is mediated by beta-2 adrenergic receptors. In the urinary bladder base noradrenaline, phenylephrine and B-HT 920 induced strong contractile effects. These contractile responses were inhibited by the alpha antagonist phenoxybenzam...
A urethral extension technique to correct urine pooling (vesicovaginal reflux) in mares. A surgical technique involving reconstruction of the caudal vaginal vault was used to correct vesicovaginal reflux in 32 of 34 mares. After surgery, 22 of 24 mares became pregnant, and embryos were harvested for transfer from 6 of the other 10 mares. It was concluded that the procedure was safe and efficacious.
Urachal remnant as a cause of pollakiuria and dysuria in a filly. A urachal remnant, causing pollakiuria and dysuria, was diagnosed by rectal palpation of a urinary bladder adhesion and endoscopic visualization of a urinary bladder diverticulum. Surgical excision of the remnant resulted in relief of abnormal micturition, but the filly was euthanatized 9 months after surgery because of a chronic ventral midline incisional infection. Pollakiuria and dysuria associated with urachal abscessation occur most commonly in calves. This report documents the syndrome in a horse.
Correction of bilateral ureteral defects in a foal. Bilateral ureteral defects were diagnosed as the cause of depression and azotemia in an 8-day-old Thoroughbred filly. The azotemia resulted from accumulation of urine in the retroperitoneal area. A ventral midline laparotomy was performed, and defects found in both the left and right ureter were repaired. Uroperitoneum and abdominal distention, presumably from urine leakage at the left ureteral surgery site, were detected on the fourth postoperative day and necessitated abdominal drainage. Thirty-six hours later, the leakage stopped spontaneously, and the foal recovered normally. This report s...
Exploratory celiotomy for suspected urinary tract disruption in neonatal foals: a review of 18 cases. The medical records of 18 neonatal foals, in which exploratory celiotomies were performed for suspected urinary tract lesions, were reviewed. Despite clinical signs and laboratory values indicative of disruption of the urinary tract, three foals did not have a site of urinary tract leakage at surgery. Eight foals had ruptured bladders and seven foals had urachal lesions. Ultrasonography was used as a pre-operative diagnostic procedure in eight foals to evaluate the presence of free peritoneal fluid and urinary tract integrity. Nine foals were alive six months after discharge. Seven of the nine...
Effects of halothane anesthesia on the clearance of gentamicin sulfate in horses. Inhalation anesthetics decrease the clearance of some drugs that are eliminated by renal excretion. The purpose of the study reported here was to investigate the effects of halothane anesthesia on the pharmacokinetics and urinary excretion of gentamicin sulfate, using the horse as a model. Using a crossover design, pharmacokinetic values after a single IV dose of gentamicin (4 mg/kg) were compared in halothane-anesthetized and unanesthetized horses. Compared with unanesthetized horses, the anesthetized horses had significant decreases in total body clearance (P less than 0.01) and apparent vol...
Treatment of two mares with obstructive (vaginal) urinary outflow incontinence. Two mares were examined because of urinary incontinence. Abnormalities of the genitourinary tract were identified and were corrected surgically. Urinary incontinence in mares generally is associated with a poor prognosis. The importance of a thorough physical examination of the genitourinary tract in the mare is emphasized, and the simple and successful surgical correction of structural abnormalities of the tract in 2 mares is described.
Hematuria caused by abdominal abscessation in a foal. A 4.5-month-old Standard-bred filly was referred for evaluation of pigmenturia. Initially, the pigmenturia had resolved with the administration of antibiotics, only to recur after their withdrawal. A dark red urine sample contained numerous RBC, WBC, and gram-negative rods (Escherichia coli). Ultrasonography revealed the right kidney to be large, with multiple cystic structures and a dilated renal pelvis and calices. Cystoscopy revealed a large blood clot within the bladder and urine coming from the left ureteral opening. Urine was not observed coming from the right ureter. It was suspected th...
Urinary bladder rupture in a two-year-old horse: sequel to a surgically repaired neonatal injury. After routine cryptorchid castration, a 2-year-old Thoroughbred colt was admitted 72 hours later because of depression, abdominal distention, and pollakiuria, with production of small quantities of urine. A diagnosis of a ruptured bladder was made on the basis of a large volume of abdominal fluid and a disparity between the urea nitrogen and creatinine concentrations in the serum (70 mg/dl and 8.4 mg/dl, respectively) and in the abdominal fluid (154 mg/dl and 43 mg/dl, respectively). The colt had undergone surgical correction of a ruptured urinary bladder at 4 days of age, and a 5-cm tear thro...
Multiple myeloma in a horse. Multiple myeloma was diagnosed in a horse on the basis of clinical signs, protein electrophoresis pattern, Bence-Jones proteinuria, and radiographic changes in bone. The horse had mild depression, weight loss, edema of the distal portion of the left hind limb, anemia, hyperproteinemia, and monoclonal gammopathy in the beta 2 region. Radiographically, punctate cortical lysis of bone was seen. Specific treatment for the multiple myeloma was not attempted and the horse was euthanatized.
Urethral pressure profilometry in mares. A technique was developed for recording urethral pressure profiles (UPP) in mares. Profiles were obtained from 12 clinically normal mares and from 3 mares with urinary incontinence. Variables measured on the profile included intravesicular pressure and maximal urethral closure pressure. The mean maximal urethral closure pressure of the incontinent mares was significantly less (P less than or equal to 0.001) than that of the normal mares. The technique is simple and reliable for objectively evaluating urethral pressures in mares.
Cystometrography and urethral pressure profiles in healthy horse and pony mares. Cystometrography and urethral pressure evaluations were performed in 7 horse mares and 5 pony mares before and after sedation with xylazine. Before sedation, mean (+/- SD) maximal bladder contraction pressure was 91.4 +/- 16.5 cm of H2O in horses and was 86.0 +/- 14.4 cm of H2O in ponies, and maximal urethral closure pressure was 49.1 +/- 19.4 cm of H2O in horses and 37.7 +/- 14.4 cm of H2O in ponies. A significant difference was not found between values of nonsedated vs sedated animals. Only values for threshold volume were significantly different (P less than 0.05) between nonsedated horses ...
Salt consumption and the effect of salt on mineral metabolism in horses. The voluntary salt consumption of mature unexercised horses was measured weekly for up to 45 weeks. Voluntary intake among horses was quite variable ranging from 19 to 143 g of salt per day and was inversely related to total salt intake (salt in feeds plus voluntary intake). Mean daily voluntary salt consumption was 53 g. Season of the year did not influence voluntary intake. In preference tests which evaluated every two choice combination of 0.2% and 4% NaCl in test diets fed daily for four days, ponies generally preferred diets containing the lower amount of salt. In similar preference studi...
Identification of uroliths by infrared spectroscopy. Wet chemical tests have deficiencies when applied to mixtures containing silica, which are common in the uroliths of some domestic animals. Consequently, the applicability of an infrared spectroscopic method was tested on 104 uroliths obtained from cattle, sheep, goats, horses, pigs, dogs, a chicken and a rabbit during diagnostic investigations. The following components were satisfactorily identified: silica, calcium oxalate, calcium carbonate, calcium phosphate, magnesium ammonium phosphate, magnesium phosphate and urates. The infrared characteristics of these compounds and their mixtures are...
Estimation of urinary flow rate in weanling and yearling horses. In an attempt to validate the use of urinary creatinine concentration as an index of urinary flow rate, a series of timed quantitative urine collections were done on several groups of weanling and yearling ponies and Thoroughbreds. A total of 411 urine samples were generated by 19 ponies and 12 Thoroughbreds. Urinary flow rates and urinary creatinine concentrations were measured. When all the data were examined, urinary flow rates were independent of creatinine concentrations. However, for any given animal, daily urinary creatinine excretion was constant over several days, and urinary creatini...
Renal carcinoma in a horse. A poorly performing nine-year-old thoroughbred mare was presented because of chronic weight loss. On rectal examination an abdominal mass was palpated and, on percussion of the right flank from the 11th to 13th intercostal space, a large area of dullness was delineated. Biopsies taken from the liver region and through the rectum revealed a malignant metastasising tumour of the urinary system. After euthanasia, the post mortem findings confirmed the presence of a papillary renal carcinoma with multiple metastases into the omentum and peritoneum.
Serum and urinary biochemistry and enzyme changes in ponies with acute renal failure. Serum and urinary biochemical changes were recorded in 5 ponies in which acute tubular nephrosis had been induced over 5 days with mercuric chloride and potassium dichromate. Serum osmolality, the serum concentrations of urea nitrogen, creatinine, sodium, potassium and chloride, and blood pH and blood gases were measured daily for 14 days or until humane euthanasia was performed. Levels of the same substances were quantitated daily in urine. In addition, routine urinalyses and determination of urinary gamma glutamyl transferase (GGT) activity were performed on each sample. Changes in the value...
Urinary enzyme concentrations in healthy horses. Urinary concentrations of gamma glutamyl transferase (GGT), alkaline phosphatase (AP), aspartate aminotransferase (AsAT), and alanine aminotransferase (AAT) were measured in 32 healthy horses (16 geldings and 16 females) at the same time on 2 consecutive days. The subjects were divided into 4 ages groups, each comprising 8 horses (4 of each sex). In 10 of the geldings, urine was collected continuously for 72 hours, with catheterized samples being obtained at 0800, 1400 and 2000 hours, and an aliquot of the pooled urine being taken every 24 hours. Urinary enzyme activity was found to be unrelat...
Crystalline composition of equine urinary calculi. X-ray diffraction crystallography was used to determine the crystalline composition of 18 equine urinary calculi, including stones originating in the kidney, bladder and urethra. Calcium carbonate in the form of calcite was found to be the major component in all calculi examined. Other components commonly found included weddellite and substituted vaterite. Urine deposits from a number of normal horses were also examined. The significance of these findings, as well as those from a number of previous reports, are discussed in relation to the possible aetiology of urolithiasis in the horse.