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A thin layer chromatographic method is presented for determining ethylene glycol in urine. The method uses 5% vanillin in sulfuric acid as the chromogenic reagent. Since the method is simple and sensitive, it provides a practical means of diagnosing ethylene glycol poisoning in clinical situations.

In 75 bitches with pyometra single urine samples were examined for gamma-glutamyl transferase (gamma-GT), protein, glucose, specific gravity, bacteria, red blood cells and white blood cells. Serum samples were examined for urea, creatinine, inorganic phosphate and gamma-GT. Biochemical findings were compared with the degree of illness (clinical signs). Twenty one bitches had no signs of renal disease. Seventeen showed only glomerular damage indicated by proteinuria without signs of proximal tubular damage. Thirty seven bitches had increased urinary gamma-GT levels, indicating proximal tubular lesions, which were associated with proteinuria in 35 and renal failure in 16 of them, and worse clinical findings. In all bitches with pyometra serum levels of gamma-GT were comparable to values in control bitches. Glomerular dysfunction seemed to precede proximal tubular lesions, so that gamma-GT-uria in bitches with pyometra was not an early but rather a late indication of a more profound degree of renal dysfunction, that is, proximal tubular renal damage developed after glomerular dysfunction and preceding renal failure.

Uroliths composed primarily of calcium phosphate are identified in approximately 3 per cent of canine stone patients. Predisposing factors to the formation of calcium phosphate uroliths include elevated urine pH, hypercalciuria, and the presence of crystallization inhibitors and promoters. Medical therapy of patients forming calcium phosphate uroliths should initially be directed at removing factors contributing to urine supersaturation with calcium phosphate.

The clinical problems and results of urinalyses of 500 dogs were reviewed and summarized to compare the sensitivities for detection of abnormalities indicative of urinary system disease among qualitative (sulfosalicylic acid [SSA]), quantitative (Coomassie brilliant blue [CBB]), and indexed (urinary protein/creatinine ratio [U(P/C)]) determinations of urinary protein loss vs microscopic examination of urine sediment. False-negative rates for the detection of microscopically abnormal urine specimens were 5.4% for SSA greater than or equal to 1+, 8.5% for CBB greater than or equal to 1.0 mg/ml, 9.7% for U(P/C) greater than or equal to 1.0, and 7.7% for CBB + U(P/C). A discriminatory U(P/C) value of 2.0 would have excluded dogs with clinically relevant proteinuria in the lower ranges. Proteinuria was not detected in 4.4% (22/500) of the specimens in which important numbers of leukocytes or bacteria were observed. False-negative rates for combined interpretation of quantitative protein concentration and U(P/C) were not significantly different (P greater than 0.10) from SSA alone. Degrees of azotemia were higher (high serum creatinine concentration, P greater than 0.10 and high serum urea nitrogen concentration, P less than 0.05) and prevalence of chronically diseased dogs was greater (P less than 0.005) in dog categories with higher U(P/C) values. More quantitative determinations of urinary protein loss as a screening test offer potential labor-saving and diagnostic advantages in the identification of urinary disease over more qualitative routine screening methods.

This article contains an analysis of data compiled from 813 specimens of canine uroliths submitted to the Urinary Stone Analysis Laboratory at University of California School of Veterinary Medicine.

Effective treatment and prevention of urolithiasis depends on accurate determination of the chemical nature of the uroliths. A widely used qualitative chemical procedure was compared with quantitative crystallographic analysis of 272 canine uroliths. Agreement between the 2 methods was 78%. Qualitative analysis failed to detect 62% of calcium-containing uroliths and 83% of carbonate apatite uroliths. Qualitative analysis gave false-positive results for urates in 55% of cystine uroliths. Mixed uroliths comprising 6% of the total could not be classified without quantitative analysis. Silicate, cystine, and urate uroliths generally were of pure composition. Crystallographic analysis indicated the following distribution of major types: struvite, 69%; calcium oxalate, 10%; urate, 7%; silicate, 3.5%; cystine, 3.2%; calcium phosphate, 1%; and mixed, 6%. Among dogs with struvite uroliths, 66% had positive results of bacterial culturing from the urinary bladder. Six breeds (Miniature Schnauzer, Welsh Corgi, Lhasa Apso, Yorkshire Terrier, Pekingese, and Pug) had a significantly higher risk for urolithiasis, compared with other breeds. The German Shepherd Dog had a significantly lowered risk, compared with other breeds. Two breeds had significant relationship to a specific type of urolith: Miniature Schnauzer for oxalate, and Dalmatian for urate (P less than 0.001). It was concluded that quantitative analysis, using crystallography, was superior for the detection of calcium oxalate, carbonate apatite, cystine, urate, and mixed uroliths.

Crystalluria results from oversaturation of urine with crystallogenic substance. However, oversaturation may occur as a result of in vitro as well as in vivo events. The microscopic appearance of crystals only represents a tentative identification of their composition because variable conditions associated with their formation, growth, and dissolution may alter their appearance. Definitive identification is dependent on physical methods such as optical crystallography, x-ray diffraction, and electron microscopic analysis.

A standard intravenous glucose tolerance test (IVGTT) and the insulin response to the glucose loads were studied in 14 cases of diabetes mellitus in dogs. In addition, urinary glucose excretion, and clearances of urea, creatinine and phosphate were also determined in these dogs. All diabetic dogs were characterized by glucose intolerance as expressed by an abnormal half-time (T 1/2) or fractional clearance rate (k-value) and were further classified as Types I, II or III diabetes on the basis of their insulin responses. Renal functional impairment was observed in about 60 percent of the cases and was generally mild. There appeared to be no apparent relationship between advanced chronic renal disease and severity of diabetes in dogs.

Ochratoxin A and citrinin, both mycotoxins, were given separately and combined to young Beagle dogs for 14 days. Ochratoxin A, 0.1 and 0.2 mg/kg, was given by capsule, and citrinin, 5 and 10 mg/kg, was dissolved in ethanol and given by intraperitoneal injection. Clinical signs of toxicosis in dogs given 10 mg/kg citrinin and the higher combined doses included anorexia, retching, tenesmus, weight loss, prostration and death. Severity of the clinical disease and mortality were increased when the mycotoxins were combined, which indicated synergism. The clinicopathological abnormalities reflected renal damage, in that glutamic oxaloacetic transaminase and lactic dehydrogenase increased in the urine of the dogs with clinical signs of poisoning. Serum lactic dehydrogenase was increased in dogs given 10 mg/kg citrinin. Cellular and granular casts, ketones, protein and glucose were in the urine of dogs given large doses of citrinin alone or combined with ochratoxin A. Serum concentrations of sodium, potassium and chloride in the dogs given high doses of each group.

Dwarfism in the Norwegian Elkhound occurred as a result of a generalized disturbance in endochondral ossification. Radiographic changes included flaring and increased width of the distal metaphyses of the radius and ulna, delayed ossification of the cuboid bones of the carpus, and reduction in length of the vertebral bodies. The zone of chondrocyte proliferation was decreased in width and contained areas of abnormal cell column formation alternated with wide areas of matrix. Chondrocytes in all zones contained one or more inclusions bounded by a smooth discontinuous membrane. The material within the inclusions appeared homogeneous and stained blue-green with Movat's pentachrome and deep blue with alcian blue-periodic acid-Schiff at pH 1.0 and 2.6. The distribution of ruthenium red granules in the matrix frequently revealed poor differentiation into territorial and interterritorial zones. Twenty-four-hour urine samples were negative for glucose, and the glycosaminoglycan excretion pattern was normal.

Hyponatremia with simultaneous renal sodium loss was associated with the inappropriate secretion of antidiuretic hormone in a dog with heartworm disease. Antidiuresis caused expansion of extracellular fluid volume, which induced renal salt wasting and a negative sodium balance. The combination of water retention, salt wasting, and inactivation of intracellular solute contributes to the decrease in serum sodium concentration. Water intoxication due to hypotonicity of body gluids induced anorexia, depression, weakness, and incoordination.

Clinical and histopathologic findings in 21 dogs with glomerular disease were reviewed. Diagnoses included amyloidosis, glomerulonephritis, and secondary glomerular atrophy. Dogs with amyloidosis excreted the largest amount of urinary protein per day, and 5 of 6 so affected had clinical signs of advanced renal disease at the time of examination. Dogs with glomerulonephritis excreted significantly less urinary protein per day, and none had clinical signs of advanced renal disease at the time of examination. The magnitude of proteinuria was correlated more with the nature of the glomerular lesion than with the stage of renal disease.

Renal cortical biopsies of 51 dogs with spontaneous proteinuria were examined by histology, electron microscopy and immunofluorescence. Glomerular lesions were classified in four groups: mesangioproliferative, membranoproliferative and membranous glomerulonephritis and amyloidosis. The glomerular and the tubulointerstitial lesions were graded, using a semiquantitative system. The results were used for the calculation of correlation coefficients between several parameters. A positive correlation was found between the severity of glomerular and tubulointerstitial lesions. Fibrin detection by immunofluorescence and histochemical methods appeared not to be correlated. The presence of electron dense deposits correlated only with the fluorescence for IgG and C3. Fluorescence for IgA and IgM was frequently observed in cases with or without dense deposits.

A study was performed to compare qualitative test results of canine uroliths with quantitative test results. Qualitative test results were in agreement with quantitative test results in only 96 of 223 specimens (43 per cent). Lack of agreement was caused by false-negative qualitative test results (85 of 223), false-positive qualitative test results (15 of 233), and a combination of false-negative and false-positive qualitative test results (27 of 233). This study indicates that the veterinary profession should abandon exclusive use of qualitative chemical test kits for uroliths.

Renal tubular carcinoma was believed responsible for hematuria and extreme leukocytosis in a dog. Other paraneoplastic syndromes possibly associated with this neoplasm included fever, thoracolumbar hyperesthesia, and anemia attributable to myelophthisis. All clinical and clinicopathologic abnormalities resolved after unilateral nephrectomy. Neutrophil cytochemical stains were used to differentiate leukemoid reaction from myelocytic leukemia as the cause of the leukocytosis. The extreme leukocytosis in this dog may have been leukemoid reaction caused by production of colony-stimulating factor by the renal tubular carcinoma.

Urinary tract infection should be considered in a differential diagnosis on the basis of history, physical examination, and urinalysis. To definitively diagnose urinary tract infection, significant bacteriuria must be found by quantitative bacterial culture. The absolute definition of significant numbers of bacteria varies with the method of collection because of the possibility of contamination with the normal bacterial flora of the lower genitourinary tract. Numbers of bacteria are also influenced by the manner in which urine samples are handled, by urine concentration, and by frequency of voiding. Quantitative and qualitative urine cultures should also be used to monitor the efficacy of treatment in chronic and recurrent infections. Cultures should be repeated three to five days after the termination of antimicrobial therapy to ensure elimination of infection. If feasible, cultures should also be repeated two to three days after begining therapy to ensure the antimicrobial agent selected is effective. Remission of clinical signs should not be used to judge efficacy of treatment, especially in chronic or recurrent infections, since infections can persist without causing clinical signs, particularly if bacterial numbers are temporarily reduced. Determination of the minimum inhibitory concentration of an antibiotic for a particular bacteria is preferable to Kirby-Bauer antibiotic sensitivity testing in urinary tract infection because of the difference in serum and urine concentrations of most antibiotics. Bacteria are not sensitive or resistant to an antibiotic but rather to a concentration of that antibiotic. If Kirby-Bauer sensitivity testing is used for urinary tract infection, results must be interpreted carefully since drugs reported as ineffective may be effective in vivo.

Spontaneous proteinuria in otherwise clinically normal adult Beagles 4-6 years old was studied for 2 years. Eighteen dogs, representing a population of 218 Beagles, were placed into three groups: group I, nonproteinuric; group II, intermittently proteinuric; group III, persistently proteinuric. The groups were alike on the basis of laboratory tests, except urinary protein loss. Proteinuria was persistent in most affected dogs but not progressive during the 2 years. The loss of proteins with high molecular weight, including alpha-, beta-, and gamma-globulins, suggested the proteinuria was of glomerular origin. There were glomerular lesions but no other significant change in the kidneys and urogenital system. Lesions were generalized and characterized by prominent, local or diffuse mesangial proliferation and by thickening, wrinkling, and splitting of the glomerular basement membrane. The subendothelial space was often widened and contained electron-dense deposits. Similar electron-dense deposits, as well as lipid and mineral, were in the mesangium. Alterations in visceral epithelial cells and endothelium were prominent. Periglomerular sclerosis was present but tended not to correlate with the severity of mesangial change in any given renal corpuscle. The severity of both mesangial and periglomerular changes increased with increasing proteinuria. Immunofluoescence studies demonstrated granular discontinuous localization of IgG and betaIC-globulins in the glomerular capillaries and mesangium. Similar localization was seen but to a lesser extent in nonproteinuric dogs. The glomerular lesions seen in these clinically healthy, proteinuric dogs are similar to those described in various canind diseases associated with terminal renal failure.

A method for collecting body fluids for cytological examination and their subsequent preparation and staining is described. The results of the cytological examination of 80 dogs and 26 cats over a period of three years are reported, indicating the number and types of condition which can be diagnosed, together with the clinicopathological correlations.

The daily excretion of urinary protein was evaluated in 8 conditioned research dogs and in 10 hospitalized, proteinuric dogs, using 24-hour urine collections. Concurrent with each 24-hour urine collection, a 5- to 10-ml urine specimen was obtained during midday. The ratio of urine protein to urine creatinine concentration was determined from the single urine specimen for each dog. Linear regression analysis was used to calculate the correlation between that ratio and the 24-hour urinary protein loss (mg/kg of body weight). The coefficient of determination was significant (r2 = 0.95, P less than 0.0001). Determination of the protein-to-creatinine ratio in a single urine specimen was found to be a sensitive, rapid, and dependable diagnostic technique for detection and quantitative estimation of proteinuria.

Recurrent struvite crystalluria and urolithiasis in a cross-Labrador bitch was studied using a combined Coulter-Counter and scanning electron microscope (SEM) approach. Staphylococcus bacteria were cultured from the patient's urine as well as from the calculi themselves. Urine samples were subjected to particle counting and sizing during active and non-active periods of stone formation. Size distribution curves so obtained were identical as were those derived from sterile and non-sterile specimens. These showed a peak incidence at a diameter of 5 microns. Particle sizes for 6 controls were also determined and showed an even distribution over a much wider range with small peaks occurring at 3, 10, and 20 microns diameters. SEM studies of urine sediments revealed the presence of struvite crystals in all the controls as well as in the stone-former. These occurred in a variety of shapes and sizes but were generally larger in the controls. SEM also revealed intimate admixtures of struvite and apatite in calculi surgically removed from the patient. The results of this study indicate that crystal numbers are of greater significance than crystal size. It is also suggested that Cross-Labradors may be unusually predisposed to struvite crystalluria. The repeated recurrence of struvite urolithiasis in the subject indicates a possible inherent physiological malfunction in the animal's ability to cope with this crystalluria. The absence of a nucleation inhibitor in the stone-former's urine is also postulated.

A modified water-deprivation test was performed on 12 polyuric and 4 clinically normal dogs. Immediately after maximal urine osmolality had been achieved with water deprivation, antidiuretic hormone was injected to test further renal concentrating ability. The test provided accurate diagnosis of severe hypothalamic-neurohypophyseal diabetes insipidus in 3 dogs, partial diabetes insipidus in 2 dogs, and primary (psychogenic) polydipsia in 2 dogs. Five polyuric dogs with hyperadreno corticism had a response to the modified water-deprivation test similar to that of dogs with partial diabetes indipidus.

In the last 17 years, 55 of 2,125 (2.6%) purebred beagles maintained in a closed colony had urolithiasis. Males comprised 72.7% of the affected animals. All the uroliths except one set in the kidneys were in the urinary bladder, the urethra, or both. All uroliths were nearly pure magnesium ammonium phosphate hexahydrate. Partially inbred beagles had a 10.7% incidence of urolithiasis, compared to a 2.0% incidence in an outbred line.

Metabolic disorders, medication, and diagnostic agents may be associated with urolithiasis in dogs. Examples of uroliths that have been uncommonly encountered in dogs include xanthine, dolomite, tetracycline, and sulfonamides. Detection of these and other apparently uncommon uroliths requires a high index of suspicion and proper methods of analysis.

Serum uric acid and phosphorus concentrations were determined for 27 dogs with multicentric lymphosarcoma before and after chemotherapy. Mean serum uric acid values in dogs before treatment were significantly higher (P less than 0.05) than those of a control group of healthy dogs. Serum uric acid values did not change after treatment. Of the 27 dogs, 13 had 24-hour urine collections to determine endogenous creatinine clearance and quantitation of uric acid and phosphorus excretion before and after treatment for lymphosarcoma. Mean values for 24-hour creatinine clearance before and after treatment were statistically similar in dogs with lymphosarcoma, although the values were lower than those in a normal range. Total urinary phosphorus excretions were increased significantly (P less than 0.01) after treatment without change in fractional excretion. Chemotherapeutic agents used accounted for the significant (P less than 0.05) increase in urine volume after treatment and may have affected the excretion of uric acid and phosphorus. Seemingly, dogs with uncomplicated lymphosarcoma rarely have renal dysfunction or clinically important alterations in uric acid or phosphorus excretion secondary to rapid tumor lysis. However, preexisting renal disease or systemic complications, such as hypercalcemia, may be associated with increased risk of further renal impairment during treatment.

The etiopathogenesis of uric acid, sodium acid urate, and ammonium acid urate uroliths in non-Dalmatian dogs appears to be a complex phenomenon. It may involve one or more pathologic and/or physiologic processes acting independently or in concert to increase urinary concentration of lithogenic substances that result in initiation, growth, and retention of urate uroliths. Increased urine uric acid concentration and/or urinary excretion of uric acid appear to be primary predisposing factors in urate lithogenesis. Specific disorders resulting in hyperuricuria may involve abnormalities of increased synthesis, diminished biodegradation, and/or enhance excretion of uric acid. In addition, ammonium ion, hydrogen ion, and other organic and inorganic urine constituents appear to have major influences on urate urolith formation. Unfortunately, many specific disorders of uric acid metabolism and other factors promoting or inhibiting urate urolith formation remain poorly characterized in the majority of non-Dalmatian dogs with urate urolithiasis. Growing awareness of the significance of urate uroliths in non-Dalmatian dogs should encourage further investigation into the identification, characterization, and quantitation of parameters influencing urate lithogenesis. Results of such studies are required for development of practical and effective strategies for treatment and prevention of canine urate urolithiasis.

Homozygosity for a defective recessive gene results in all Dalmatians having elevated concentrations of urine uric acid and predisposes them to formation of purine uroliths. Why some animals form uroliths and others do not is not known. In a pilot breeding experiment, the incidence of sensorineural deafness among backcrossed, high urine uric acid Dalmatians was significantly higher (probability less than 0.05) than among low urine uric acid siblings. Urine uric acid values for Dalmatians reported in the literature are not likely to be comparable, because uric acid appears to be more likely to precipitate in Dalmatian urine than in the urine of other dogs and man. Heating, alkalinization, and thorough mixing are required whenever specimens are transferred from one container to another or an aliquot is removed for assay.

A bacteriological investigation of 199 urinary specimens from dogs with symptoms of urinary tract infections is presented. No bacterial growth was detected in 55.7% of all specimens examined. Isolation rates from urine specimens from noncatheterized and catheterized dogs were 35.2 and 66.7%, respectively, thus emphazising the importance of the sampling method and also that urinary tract infections in dogs can not be diagnozed solely on the basis of clinical symptoms. Bacteria belonging to the Enterobacteriaceae were most common isolated. Ampicillin was the drug to which resistance was least common (16.2%) while 79.1% of the strains examined were resistant to sulphonamide.

Macroscopic examination of urine is an integral part of urinalysis, and blood and bile pigments are a common cause of abnormal coloration. Urine SG is a convenient index of urine concentration and should be correlated with the patient's hydration status to determine the ability of the kidneys to concentrate and dilute urine. The pH of urine of dogs and cats normally is dietary dependent, but alkaline urine may suggest that the urinary tract is infected with a urea splitting organism. The dipstick test for proteinuria is convenient but less reliable than the sulfosalicylic acid method. The dipstick test for blood should not be used as a substitute for microscopic examination of urine but is of value in detecting hemoglobinuria and myoglobinuria, when red cells may be absent in the sediment. The finding of glucose, ketones, and bilirubin in urine, when interpreted properly, may indicate the presence of disease processes not associated with the urogenital tract. Microscopic examination of urine sediment must be interpreted in combination with the physical and chemical composition of urine, but excessive numbers of cells, casts, crystals, and bacteria may provide evidence of disease. The absence of these structures in the sediment, however, does not eliminate the possibility of disease. The ability of the kidneys to concentrate urine is dependent on normal kidney function and the production and release of ADH. A urine SG greater than 1.030 in dogs and 1.035 in cats indicates that the functions associated with concentrating urine are adequate. In the evaluation of the patient's ability to form concentrated urine, the status of hydration must be considered; this may require water deprivation tests or administration of ADH. The estimation of blood urea nitrogen concentration, with the use of test strips, may provide a convenient but not specific measure of renal function.

The initial physical signs, clinical problems, and results of 1,000 consecutive urinalyses of canine patients at the Colorado State University Veterinary Teaching Hospital were reviewed and summarized to compare microscopic and physicochemical examinations of urine. Physicochemical examination alone would have resulted in an 11.4% (64/562) false-negative rate for detection of abnormal urine specimens without consideration of patient risk for genitourinary disease. The effects of a discriminative diagnostic algorithm on macroscopic examination sensitivity were determined. Fifty-one macronegative/micropositive and 85 macro- and micronegative specimens were obtained from higher-risk patients with history, physical signs, clinical problems, or serum biochemical analysis results indicative of predisposition to genitourinary disease, which would have warranted complete urinalyses regardless of physicochemical findings. Exclusion of these patients from evaluation of physicochemical examination sensitivity in order to consider such methodology's impact as a screening procedure only for those patients whose genitourinary disease was not already suspect resulted in a significantly (P less than 0.001) lower false-negative rate of 3.05% (13/426).

In a group of 58 dogs with proven pyometra, 10 bitches developed renal failure, combined with increased (p less than 0.01) urinary excretion of protein, glucose, gamma-glutamyltransferase (GGT), alkaline phosphatase (AP), amylase, lipase and casts. Thirty-two bitches without renal failure showed nevertheless signs of renal dysfunction as indicated by increased (p less than 0.01) urinary levels of protein, glucose, GGT, AP and amylase. Six bitches without significant proteinuria showed increased (p less than 0.02) urinary levels of GGT, AP as well as amylase. Thus renal injury was detected in 72 per cent of the bitches. Sixteen bitches showed normal urinary levels of protein, glucose, GGT, AP, amylase and lipase, indicating absence of renal disease.

The urinary excretion of free, total and non-dialyzable hydroxyproline appeared to be similar in both chondrodysplastic and non-chondrodysplastic Alaskan Malamutes of ages six and twenty-six weeks suggesting the metabolic defect was probably not related to a gross disturbance in collagen metabolism. Urinary hexuronic acids also appeared to be similar in levels for both populations. A four-fold increase in urinary mucopolysaccharide levels observed at age twenty-six weeks in the chondrodysplastic Alaskan Malamute suggested a deviation from normal. The magnitude and variability of deviation were not sufficient to indicate that this condition could serve as a model for the mucopolysaccharidosis of man but probably indicated a delayed maturation process.

Medical therapy that may be effective in promoting dissolution of canine ammonium urate uroliths includes the following: reduction of dietary purines, reduction in in vivo production of uric acid, and alkalinization of urine.

Cystine uroliths form as a result of a complex metabolic disturbance in amino acid metabolism and transport. The inheritance of this disease is obscure because it does not follow a standard mendelian pattern. Uroliths are a vexing clinical problem because the recurrence rate is high. Accurate diagnosis of uroliths requires use of crystallographic methods. The renal defect leading to excessive excretion of cystine is variable. The only effective method of prevention of recurrence is use of D-penicillamine, which is poorly tolerated by some dogs.

The level of delta amino levulinic acid (ALA) was determined in the urine of normal cows and dogs, and in the urine of dogs, cows and cats with a variety of diseases. ALA was measured in the urine of two steers and two dogs experimentally poisoned with lead. Experimental lead poisoning was followed by increased excretion of ALA in the urine. Higher levels of ALA were present in the urine of sick dogs and cats than in the urine of sick cows.