Evaluation of blood urea nitrogen and serum creatinine concentrations as indicators of renal dysfunction: a study of 111 cases and a review of related literature.

Blood urea nitrogen concentration (BUN), serum creatinine concentration (SC), and BUN/SC ratios, as recorded for 111 dogs and cats with azotemia, were evaluated to determine their usefulness in evaluation of renal dysfunction. Cases were categorized into prerenal, renal, and post-renal causes of azotemia, on the basis of histologic and clinical criteria. The severity of azotemia varied within groups, but the mean value for degree of azotemia was lowest in the prerenal group. The BUN/SC ratios were highest when azotemia was mild, regardless of cause. The BUN/SC ratios in the 3 groups were not significantly different when the degree of azotemia was considered, indicating that differentiation of renal from extrarenal azotemia was not possible in the dog and cat, on the basis of relative values of BUN and SC. Comparison of BUN/SC ratios in acute and chronic azotemia of comparable magnitude revealed no significant differences between groups, indicating that this ratio cannot be used to differentiate acute and chronic azotemia. Following supportive therapy, BUN decreased significantly (P less than 0.05) more than SC, suggesting that extrarenal factors contributed to the increased BUN and that proportionately more urea than creatinine was excreted by the kidneys during therapy. The BUN/SC ratios varied widely and to a similar degree in all groups examined. Inasmuch as the BUN and SC were not correlated with more accurate measurements of renal function, conclusions could not be drawn concerning the superiority of either factor as a measure of renal function. Many nonrenal factors, previously identified, influence serum concentration of urea and creatinine. In recent studies involving azotemic human beings and rats, it was suggested that up to 25% of the urea and 65% of the creatinine produced in the body is degraded by enteric bacteria rather than excreted directly by the kidneys. These data indicate that neither BUN or SC can be used as precise tests of renal function, although SC is subject to alteration by fewer nonrenal factors than is BUN. In older medical and veterinary medical literature, the use of SC as a prognostic indicator had been advocated. Newer findings on the pathophysiology of creatininemia and retrospective case studies do not support this view. In the present study, severe creatininemia was documented in cases in which primary renal dysfunction did not exist. It was concluded that BUN and SC should continue to be regarded as crude indexes of renal function. Clinical value lies in the relative ease of their determination. Because of their lack of sensitivity, more specific evaluation of renal function (urine concentrating ability, phenolsulfonphthalein excretion) may be indicated when BUN and SC are normal or only slightly elevated. Because extrarenal factors may alter BUN and SC, it is necessary to correlate these values with clinical and other laboratory data to differentiate renal from extra-renal azotemia. Single determinations of BUN or SC provide no basis for prognosis.     

Pretreatment clinical and laboratory findings in dogs with primary hyperparathyroidism: 210 cases (1987-2004)

OBJECTIVE: To evaluate pretreatment clinical and laboratory findings in dogs with naturally occurring primary hyperparathyroidism. DESIGN: Retrospective study. ANIMALS: 210 dogs with primary hyperparathyroidism and 200 randomly selected, age-matched control dogs that did not have primary hyperparathyroidism. PROCEDURE: Medical records for dogs with primary hyperparathyroidism were reviewed for signalment; clinical features; and results of clinicopathologic testing, serum parathyroid hormone assays, and diagnostic imaging. RESULTS: Mean age of the dogs with primary hyperparathyroidism was 11.2 years (range, 6 to 17 years). The most common clinical signs were attributable to urolithiasis or urinary tract infection (ie, straining to urinate, increased frequency of urination, and hematuria). Most dogs (149 [71%]) did not have any observable abnormalities on physical examination. All dogs had hypercalcemia, and most (136 [65%]) had hypophosphatemia. Overall, 200 of the 210 (95%) dogs had BUN and serum creatinine concentrations within or less than the reference range, and serum parathyroid hormone concentration was within reference limits in 135 of 185 (73%) dogs in which it was measured. Urolithiasis was identified in 65 (31 %) dogs, and urinary tract infection was diagnosed in 61 (29%). Mean serum total calcium concentration for the control dogs-was significantly lower than mean concentration for the dogs with primary hyperparathyroidism, but mean BUN and serum creatinine concentrations for the control dogs were both significantly higher than concentrations for the dogs with primary hyperparathyroidism. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that urolithiasis and urinary tract infection may be associated with hypercalcemia in dogs-with primary hyperparathyroidism, but that development of renal insufficiency is uncommon.     

Association of systemic hypertension with renal injury in dogs with induced renal failure

Systemic hypertension is hypothesized to cause renal injury to dogs. This study was performed on dogs with surgically induced renal failure to determine whether hypertension was associated with altered renal function or morphology. Mean arterial pressure (MAP), heart rate (HR), systolic arterial pressure (SAP), and diastolic arterial pressure (DAP) were measured before and after surgery. Glomerular filtration rate (GFR) and urine protein:creatinine ratios (UPC) were measured at 1, 12, 24, 36, and 56-69 weeks after surgery, and renal histology was evaluated terminally. The mean of weekly MAP, SAP, and DAP measurements for each dog over the 1st 26 weeks was used to rank dogs on the basis of MAP, SAP, or DAP values. A statistically significant association was found between systemic arterial pressure ranking and ranked measures of adverse renal responses. When dogs were divided into higher pressure and lower pressure groups on the basis of SAP, group 1 (higher pressure, n = 9) compared with group 2 (lower pressure, n = 10) had significantly lower GFR values at 36 and 56-69 weeks; higher UPC values at 12 and 56-69 weeks; and higher kidney lesion scores for mesangial matrix, tubule damage, and fibrosis. When dogs were divided on MAP and DAP values, group 1 compared with group 2 had significantly lower GFR values at 12, 24, 36, and 56-69 weeks; higher UPC values at 12 and 56-69 weeks; and higher kidney lesion scores for mesangial matrix, tubule damage, fibrosis, and cell infiltrate. These results demonstrate an association between increased systemic arterial pressure and renal injury. Results from this study might apply to dogs with some types of naturally occurring renal failure.     

Biochemical abnormalities observed in serum of dogs infected with large Babesia in Warsaw (Poland)

Biochemical abnormalities observed in canine babesiosis are related to the severity of the disease. The primary biochemical abnormalities found in affected dogs are: increase of the serum activity of transaminases and alkaline phosphatase, azotemia, and hypoglycemia. The purposes of this study were: 1) to estimate biochemical abnormalities in dogs infected with large Babesia in Warsaw and 2) to evaluate statistically changes observed during canine babesiosis in dogs from Warsaw. Samples of serum were collected from dogs naturally infected with large Babesia. Among 2023 positive samples, 202 were randomly selected. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), creatinine, blood urea nitrogen (BUN), total serum protein (TSP), albumin and blood glucose concentration were determined with a clinical chemistry analyser. Elevated activity of ALT, AST and ALP was detected accordingly in: 64.9, 92.6 and 31.7% of dogs. Elevated creatinine concentration and BUN were detected accordingly in 30.7 and 62.4% of dogs. Decrease of TSP, albumin, BUN, and hypoglycemia was detected accordingly in: 19.8, 32.7, 1.5 and 18.3% of dogs. The most common biochemical abnormalities found in affected dogs were: increase of activity of transaminases and ALP, elevated creatinine concentration, hypoalbuminemia and hypoglycemia. These abnormalities resulted from hepatopathy, renal failure and fasting.     

Evaluation of the association between initial proteinuria and morbidity rate or death in dogs with naturally occurring chronic renal failure

OBJECTIVE: To determine whether urine protein-to-creatinine ratio (UP:C) > or = 1.0 at initial diagnosis of chronic renal failure (CRF) is associated with greater risk of development of uremic crises, death, and progression of renal failure in dogs. DESIGN: Prospective cohort study. ANIMALS: 45 dogs with CRF PROCEDURE: Dogs were prospectively assigned to 2 groups on the basis of initial UP:C < 1.0 or 2 > or = 1.0. The association between magnitude of proteinuria and development of uremic crises and death was determined before and after dogs with initial UP:C > or =1.0 were assigned to 3 subgroups and compared with dogs with initial UP:C < 1.0. Changes in reciprocal serum creatinine concentration were used to estimate decrease in renal function. RESULTS: Initially, dogs had similar clinical characteristics with the exception of systolic blood pressure and UP:C. Relative risks of development of uremic crises and death were approximately 3 times higher in dogs with UP:C > or =1.0, compared with dogs with UP:C < 1.0. Relative risk of adverse outcome was approximately 1.5 times higher for every 1-unit increment in UP:C. The decrease in renal function was of greater magnitude in dogs with UP:C > or =1.0, compared with dogs with UP:C < 1.0. CONCLUSIONS AND CLINICAL RELEVANCE: Initial UP:C > or =1.0 in dogs with CRF was associated with greater risk of development of uremic crises and death, compared with dogs with UP:C < 1.0. Initial determinations of UP:C in dogs with naturally occurring CRF may be of value in refining prognoses.     

Safety and tolerability of 3-week and 6-month dosing of Deramaxx® (Deracoxib) chewable tablets in dogs

Although non-steroidal anti-inflammatory drugs (NSAIDs) are effective in reducing pain and inflammation, these agents have adverse effects. Selective inhibitors of COX-2 are an alternative to traditional NSAIDs. Deramaxx^® [Novartis Animal Health US, Inc. (NAH), Greensboro, NC, USA] contains the selective COX-2 inhibitor, deracoxib, and is approved for the relief of pain and inflammation associated with orthopedic surgery and osteoarthritis in dogs. The safety of Deramaxx was evaluated in two target animal safety studies: 40 dogs (four dogs/sex/group) received 0, 4, 6, 8, or 10 mg/kg/day deracoxib once daily for 21 days; and 60 dogs (five dogs/sex/group) received 0, 2, 4, 6, 8, or 10 mg/kg/day deracoxib once daily for 6 months. There was a dose-dependent trend towards increased blood urea nitrogen (BUN) in treated dogs, however mean BUN values remained within the reference range at the labeled doses. In both trials, histopathology revealed focal renal tubular degeneration/regeneration in some dogs receiving ≥6 mg/kg/day deracoxib. Focal renal papillary necrosis was seen in one dog treated with 8 mg/kg/day and in three dogs receiving 10 mg/kg/day deracoxib on the 6-month study. No other parameters of renal function were adversely affected for either study. Results show that Deramaxx is safe and well-tolerated in dogs when administered as directed.     

Acute intrinsic renal failure in cats: 32 cases (1997-2004)

OBJECTIVE: To determine patient demographics, clinicopathologic findings, and outcome associated with naturally acquired acute intrinsic renal failure (ARF) in cats. DESIGN: Retrospective case series. ANIMALS: 32 cats with ARF. PROCEDURES: Cats were considered to have ARF if they had acute onset of clinical signs (< 7 days), serum creatinine concentration > 2.5 mg/dL (reference range, 0.8 to 2.3 mg/dL) and BUN > 35 mg/dL (reference range, 15 to 34 mg/dL) in conjunction with urine specific gravity < 1.025 or with anuria or increasing serum creatinine concentration despite fluid therapy and normal hydration status, and no signs of chronic renal disease. Cases were excluded if cats had renal calculi or renal neoplasia. RESULTS: Causes of ARF included nephrotoxins (n = 18 cats), ischemia (4), and other causes (10). Eighteen cats were oliguric. For each unit (mEq/L) increase in initial potassium concentration, there was a 57% decrease in chance of survival. Low serum albumin or bicarbonate concentration at initial diagnosis was a negative prognostic indicator for survival. Initial concentrations of BUN, serum creatinine, and other variables were not prognostic. Seventeen (53%) cats survived, of which 8 cats had resolution of azotemia and 9 cats were discharged from the hospital with persistent azotemia. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that survival rates of cats with ARF were similar to survival rates in dogs and that residual renal damage persisted in approximately half of cats surviving the initial hospitalization.     

Histopathologic features of canine uremic gastropathy: a retrospective study

Uremic gastritis is a term commonly used to describe the gastrointestinal signs and histopathologic changes associated with renal failure in the dog. This retrospective study reviews the clinical, serum biochemical, and postmortem histopathologic data from 28 dogs with renal failure to determine the prevalence of gastric histopathology, characterize the gastric histopathology, and identify associations between gastric histopathology and serum concentrations of blood urea nitrogen (BUN), creatinine (Cr), calcium-phosphorus product (Ca x Phos), and hematocrit. Affected and control dogs with available renal and gastric tissue, serum biochemistry data, and urinalysis data were identified over a 10-year period (1992-2002) in the pathology department postmortem examination database at the Cornell University College of Veterinary Medicine. The serum biochemistry data and histopathologic findings were scored as normal, mild, moderate, and severe. All affected dogs had derangements of BUN, Cr, or Ca x Phos with gastric histopathology in 22 of 28 dogs (79%). Dogs with renal failure had a higher prevalence of gastric histopathologic changes compared with the control group. Associated histopathologic changes in the stomach were edema (P = .008), mineralization (P = .03), and vasculopathy (P = .03). Only 1 dog had evidence of gastric ulceration. Gastric necrosis was an uncommon finding (4/28, 14%). Gastric histopathology appears to be common in dogs with renal failure and is associated with increasing severity in the serum biochemistry data. Unlike humans with renal failure, in whom gastric ulceration predominates, gastric necrosis and ulceration appear to be uncommon in dogs with renal failure.     

Progression of chronic renal disease in the dog

Progressive loss of nephron function may be caused by persistence of factors that initiated renal disease. However, newer studies suggest that nephron damage is self-perpetuating once renal mass is reduced to some critical level. Original theories on mechanisms of self-perpetuated nephron injury focused on intraglomerular hypertension and glomerular hypertrophy, but several other factors have now been incriminated, including tubulointerstitial responses, proteinuria, and oxidative stress. Studies of dogs with surgically reduced renal mass (remnant kidney model of chronic renal disease) have allowed investigation of the self-progression theory in this species. Use of this model eliminates pre-existing renal disease as a confounding factor. Data from these studies indicate that self-perpetuated renal injury is initiated when mild azotemia is induced (plasma creatinine concentration = 2 to 4 mg/dL). Thus, with naturally occurring renal disease(s), it is likely that self-perpetuated nephron damage is occurring before or at the time when most cases of chronic renal disease are diagnosed. In dogs with remnant kidneys, loss of renal function often occurs at a linear rate over time, but non-linear patterns are common as well. The reciprocal of plasma creatinine concentration, which has been used to monitor rate of progression, is only a fair marker of renal function when compared to GFR. Thus, clinical results from creatinine measurements on cases of naturally occurring disease should not be interpreted too stringently. In remnant kidney dogs, the magnitude of proteinuria (UPC ratio) was not predictive of the rate in decline of GFR, casting doubt on importance of proteinuria in causing progression of renal disease. However, progressive increases in UPC may be a marker of an accelerated rate of renal injury. Self-perpetuation of renal injury in dogs could be the sole mechanism by which naturally occurring renal diseases progress. When more information is available on the rate of progression of naturally occurring diseases, it may become apparent whether factors initially inciting renal damage have an additive effect on rate of progression.     

Canine hypertrophic cardiomyopathy.

Necropsy findings in 10 dogs with naturally occurring cardiac disease closely resembled hypertrophic cardiomyopathy in human beings and cats. Each dog had marked cardiac hypertrophy, and 8 dogs had disproportionate thickening of the ventricular septum with respect to the left ventricular free wall (compared with dogs with normal hearts or with cardiac hypertrophy due to acquired or congenital heart disease). Ratios of septum to free wall thickness in the 10 dogs ranged from 1.1 to 1.5, and 6 had ratios greater than or equal to 1.3. Marked cardiac muscle cell disorganization in the ventricular septum, characteristic of human patients with hypertrophic cardiomyopathy, was found in only 2 of the 10 dogs. Death occurred while the dogs were under anesthesia during the course of operative procedures (5 dogs) or unexpectedly in animals without previous manifestations of cardiac disease (3 dogs). Four dogs had clinical signs of congestive heart failure, including 2 with marked cardiac decompensation. Two of these 4 dogs with heart failure and 1 dog that died during unrelated surgery, but without prior signs of heart disease, had electrocardiographic evidence of complete heart block.     

犬慢性肾衰竭进程中肠道菌群代谢物短链脂肪酸水平的变化及其对肾功能的影响

本研究旨在评估短链脂肪酸在慢性肾衰竭患犬和健康犬中的水平,探究短链脂肪酸变化的原因及其对肾功能的影响.选取22例轻度慢性肾衰患犬(M-CRF组)、29例重度慢性肾衰患犬(S-CRF组)和26例健康对照犬(HC组),用16S rDNA测序技术分析肠道菌群多样性,气相色谱法检测粪中短链脂肪酸浓度.通过粪菌移植和补充丁酸钠给...     

Efficacy and safety of cefovecin in treating bacterial folliculitis, abscesses, or infected wounds in dogs

OBJECTIVE: To evaluate the efficacy and safety of administration of cefovecin, compared with cefadroxil, for treatment of naturally occurring secondary superficial pyoderma, abscesses, and infected wounds in dogs. DESIGN: Multicenter, randomized, positive-controlled clinical trial. ANIMALS: 235 client-owned dogs. PROCEDURES: Dogs with clinical signs of skin infection confirmed via bacteriologic culture were randomly allocated to receive a single SC injection of cefovecin (8 mg/kg [3.6 mg/lb]) followed by placebo administered PO twice daily for 14 days or cefadroxil (22 mg/kg [10 mg/lb]) administered PO twice daily for 14 days following a placebo injection. Two 14-day treatment courses were permitted. Treatment success was defined as reduction of clinical signs to mild or absent at the final assessment. RESULTS: Clinical efficacy achieved with cefovecin in dogs was equivalent to that observed with cefadroxil. At the final assessment, 14 days following the completion of treatment (on day 28 or 42), 92.4% (109/118) of the cefovecin group and 92.3% (108/117) of the cefadroxil group were treatment successes. There were no serious adverse events or deaths related to treatment. CONCLUSIONS AND CLINICAL RELEVANCE: A single cefovecin injection (8 mg/kg) administered SC, which could be repeated once after 14 days, was safe and effective against naturally occurring skin infections in dogs and as effective as cefadroxil administered PO twice daily for 14 or 28 days.     

Evaluation of prognostic factors in the surgical treatment of adrenal gland tumors in dogs: 41 cases (1999-2005)

OBJECTIVE: To identify preoperative predictors of survival and assess intraoperative and postoperative complications and survival rates for dogs undergoing adrenalectomy. DESIGN: Retrospective case series. ANIMALS: 41 dogs that underwent adrenalectomy. PROCEDURES: Records were reviewed to collect data regarding preoperative variables. Intraoperative and postoperative variables were also recorded. Variables were evaluated for association with survival duration via log-rank analysis for categoric variables and by use of Cox proportional hazards. Median survival times were calculated by use of Kaplan-Meier life table analysis. RESULTS: 9 (22.0%) dogs did not survive to discharge. Intraoperative mortality rate was 4.8%. Overall Kaplan-Meier median survival time was 690 days. Variables significantly associated with shorter survival times included preoperative weakness or lethargy, thrombocytopenia, increased BUN concentration, increased partial thromboplastin time (PTT), increased aspartate transaminase (AST) activity, hypokalemia, intraoperative hemorrhage, and concurrent nephrectomy. Postoperative variables significantly associated with shorter survival times included pancreatitis and renal failure. In multivariate analysis, preoperative hypokalemia, preoperative increased BUN concentration, and concurrent nephrectomy were significantly associated with a shorter survival time. CONCLUSIONS AND CLINICAL RELEVANCE: A high mortality rate was associated with adrenalectomy in dogs; however, those that survived until discharge from a hospital had long survival times. Preoperative factors associated with a shorter survival time were weakness or lethargy, thrombocytopenia, increased BUN concentration, increased PTT, increased AST activity, and hypokalemia. Studies are needed to evaluate how treatment for these factors may affect or change outcome after adrenalectomy. Dogs with adrenal masses that require concurrent nephrectomy and cause intraoperative hemorrhage have a guarded prognosis.     

Plasma and urinary trypsinogen activation peptide in healthy dogs, dogs with pancreatitis and dogs with other systemic diseases

OBJECTIVE: To determine the specificity and sensitivity of plasma and urinary trypsinogen activation peptide (TAP) concentrations in diagnosing pancreatitis in dogs. DESIGN: Retrospective analysis of clinical cases. PROCEDURE: Dogs were classified into three groups: healthy animals, dogs with confirmed pancreatitis and dogs with nonpancreatic disease, which clinically or biochemically resembled pancreatitis. This last group was further subdivided into dogs with renal and those with nonrenal disease. The plasma and urinary TAP concentration was determined by a competitive enzyme immunoassay. Clinical cases additionally had serum trypsin-like immunoreactivity concentration measured, as well as radiography and ultrasound of the abdomen and further diagnostic procedures. Nonparametric analysis of variance (Kruskal-Wallis test) was performed using Statistix 4.0 program. RESULTS: There was a wide range of urinary TAP concentration in healthy dogs (mean 52.30 nmol/L, standard deviation 55.25) that made interpretation of urinary TAP concentrations difficult in the other groups. There was a narrow reference range for plasma TAP (mean 2.67 nmol/L, standard deviation 0.93). Plasma and urinary TAP concentrations, as well as urinary TAP to creatinine ratio, were all increased in dogs that died with necrotising pancreatitis. Values were not increased in mild, interstitial pancreatitis. Increased plasma TAP concentrations were also present in dogs with severe renal disease. CONCLUSION: Plasma TAP concentration is a good prognostic indicator in naturally occurring pancreatitis in dogs. The failure of TAP to increase in mild pancreatitis, and the increase present in severe renal disease, suggests its measurement has limited application as a sole diagnostic tool for canine pancreatitis. Further investigations are required in order to explain the large variability of urinary TAP concentration and the presence of circulating TAP in healthy dogs.     

An Investigation of the Action of Neutral Protamine Hagedorn Human Analogue Insulin in Dogs with Naturally Occurring Diabetes Mellitus

Background: Neutral Protamine Hagedorn human analogue insulin (Humulin N) is commonly used for treatment of canine diabetes mellitus (DM). However, blood glucose and serum insulin concentrations in Humulin N-treated dogs with naturally occurring DM have not been reported.
Objective: To investigate blood glucose and serum insulin concentrations in the clinical setting of client-owned Humulin N-treated dogs with naturally occurring, well-regulated DM.
Animals: Ten client-owned dogs with naturally occurring, well-regulated DM.
Methods: In this clinical study, blood glucose and serum insulin concentrations were measured when dogs received food and insulin (T₀), at approximately every half hour for the next 2 hours, and then approximately every 2 hours for an additional 8 hours. Insulin duration of action was defined as the number of hours from T₀ to the lowest blood glucose concentration and until blood glucose concentration returned to an interpolated value of 70% of basal blood glucose concentration (Glucose_b).
Results: Mean percent of insulin-induced blood glucose suppression was 49.9 ± 17.1% (median, 46%; range, 29–78%). Insulin duration of action ranged from 4 to 10 hours. Blood glucose concentration increased initially and returned to Glucose_b within 0.6–2.2 hours after T₀ in 5 dogs. This initial blood glucose surge then was followed by blood glucose suppression in all 5 dogs.
Conclusions and Clinical Importance: These results suggest that Humulin N administered SC twice daily is an effective mode of treatment for dogs with naturally occurring DM. Postprandial hyperglycemia is present in some well-regulated diabetic dogs treated with Humulin N.     

Associations between proteinuria, systemic hypertension and glomerular filtration rate in dogs with renal and non-renal diseases

Proteinuria and systemic hypertension are well recognised risk factors in chronic renal failure (CRF). They are consequences of renal disease but also lead to a further loss of functional kidney tissue. The objectives of this study were to investigate the associations between proteinuria, systemic hypertension and glomerular filtration rate (GFR) in dogs with naturally occurring renal and non-renal diseases, and to determine whether proteinuria and hypertension were associated with shorter survival times in dogs with CRF. Measurements of exogenous creatinine plasma clearance (ECPC), urine protein:creatinine ratio (UPC), and Doppler sonographic measurements of systolic blood pressure (SBP) were made in 60 dogs with various diseases. There was a weak but significant inverse correlation between UPC and ECPC, a significant inverse correlation between SBP and ECPC and a weak but significant positive correlation between UPC and SBP. Some of the dogs with CRF were proteinuric and almost all were hypertensive. Neoplasia was commonly associated with proteinuria in the dogs with a normal ECPC. CRF was the most common cause leading to hypertension. In the dogs with CRF, hypertension and marked proteinuria were associated with significantly shorter survival times.     

New form of X-linked dominant hereditary nephritis in dogs

OBJECTIVE: To determine features of a new form of hereditary nephritis (HN) in dogs. ANIMALS: Parents and 16 first-generation offspring (8 males, 8 females). PROCEDURE: Adolescent dogs that developed renal failure were euthanatized and necropsied. Unaffected dogs were monitored until they were at least 2 years old. Studies included light and electron microscopy of kidneys obtained from affected and unaffected dogs and immunolabeling for collagen-IV chains in renal and epidermal basement membranes (BM). The nucleotide sequence of a portion of exon 35 of the COL4A5 gene was determined in genomic DNA isolated from affected and unaffected males. RESULTS: 7 of 8 male and 2 of 8 female offspring had proteinuria and juvenile-onset chronic renal failure, which progressed more rapidly in the males. Labeling for alpha3-alpha6(IV) chains was completely absent in renal BM of affected males and segmentally absent in affected females. Expression of alpha1-alpha2(IV) chains in glomerular BM (GBM) of affected dogs was increased. Labeling for alpha5-alpha6(IV) chains in epidermal BM was absent in affected males and segmental in affected females. Ultrastructural changes characteristic of HN were observed in GBM of affected dogs. The sequence of exon 35 of COL4A5 was normal in affected dogs. CONCLUSIONS: This renal disease is an example of X-linked dominant HN, with typical abnormalities of GBM ultrastructure and alpha(IV) chain expression. CLINICAL RELEVANCE AND IMPLICATIONS FOR HUMAN MEDICINE: Dogs with this naturally acquired progressive renal disease can be used to investigate the pathogenesis and treatment of similar disorders in human beings and dogs.     

Serum concentrations of 1,25-dihydroxycholecalciferol and 25-hydroxycholecalciferol in clinically normal dogs and dogs with acute and chronic renal failure

OBJECTIVE: To compare serum concentrations of 1,25-dihydroxycholecalciferol (1,25-[OH]2D3) and 25-hydroxycholecalciferol (25-[OH]D3) in healthy control dogs and dogs with naturally occurring acute renal failure (ARF) and chronic renal failure (CRF). ANIMALS: 24 control dogs, 10 dogs with ARF, and 40 dogs with CRF. PROCEDURE: Serum concentrations of 1,25-(OH)2D3 were measured by use of a quantitative radioimmunoassay, and serum concentrations of 25-(OH)D3 were measured by use of a protein-binding assay. RESULTS: Mean +/- SD serum concentration of 1,25-(OH)2D3 was 153 +/- 50 pmol/L in control dogs, 75 +/- 25 pmol/L in dogs with ARF, and 93 +/- 67 pmol/L in dogs with CRF. The concentration of 1,25-(OH)2D3 did not differ significantly between dogs with ARF and those with CRF and was in the reference range in most dogs; however, the concentration was significantly lower in dogs with ARF or CRF, compared with the concentration in control dogs. Mean +/- SD concentration of 25-(OH)D3 was 267 +/- 97 nmol/L in control dogs, 130 +/- 82 nmol/L in dogs with ARF, and 84 +/- 60 nmol/L in dogs with CRF. The concentration of 25-(OH)D3 was significantly lower in dogs with ARF or CRF, compared with the concentration in control dogs. CONCLUSIONS AND CLINICAL RELEVANCE: The concentration of 1,25-(OH)2D3 was within the reference range in most dogs with renal failure. Increased serum concentrations of parathyroid hormone indicated a relative deficiency of 1,25-(OH)2D3. A decrease in the serum concentration of 25-(OH)D3 in dogs with CRF appeared to be attributable to reduced intake and increased urinary loss.     

Influence of ascorbic acid on BUN, creatinine, resistive index in canine renal ischemia-reperfusion injury

Renal ischemia as a course of renal transplantation is a common cause of renal dysfunction as renal failure. The purpose of this study was to investigate the influence of ascorbic acid on blood urea nitrogen (BUN), creatinine (Cr) and resistive index (RI) for dog models with renal ischemia-reperfusion (I/R) injury. Renal ischemia was induced on 6 Beagle dogs. The left kidney was exposed to normothermic ischemia for a short period at 30 min followed by reperfusion. On the blood Cr level and RI, there was no significant difference comparing both groups. 14 days after I/R injury a significant reduction on the blood BUN level was observed in the vehicle group (34.06 mg/dl) compared to that of ischemia induced treated group (10.3mg/dl) (p < 0.05). In conclusion, administration of ascorbic acid for renal ischemic-reperfusion injury had influence on blood BUN level, but it was not revealed the influence on blood Cr and RI.     

Complications and outcomes associated with use of gastrostomy tubes for nutritional management of dogs with renal failure: 56 cases (1994-1999)

OBJECTIVE: To evaluate complications and outcomes associated with use of gastrostomy tubes in dogs with renal failure. DESIGN: Retrospective study. ANIMALS:56 dogs. PROCEDURE: Medical records were reviewed for dogs with renal failure that were treated by use of gastrostomy tubes. RESULTS: Mean +/- SD BUN concentration was 134 +/- 79 mg/dl and mean serum creatinine concentration was 9.0 +/- 3.8 mg/dl. Low-profile gastrostomy tubes were used for initial placement in 10 dogs, and traditional gastrostomy tubes were used in 46 dogs. Mild stoma-site complications included discharge, swelling, erythema, and signs of pain in 26 (46%) of dogs. Twenty-six gastrostomy tubes were replaced in 15 dogs; 11 were replaced because of patient removal, 6 were replaced because of tube wear, and 3 were replaced for other reasons. Six tubes were replaced by low-profile gastrostomy tubes. Gastrostomy tubes were used for 65 +/- 91 days (range, 1 to 438 days). Eight dogs gained weight, 11 did not change weight, and 17 lost weight; information was not available for 20 dogs. Three dogs were euthanatized because they removed their gastrostomy tubes, 2 were euthanatized because of evidence of tube migration, and 1 died of peritonitis. CONCLUSIONS AND CLINICAL RELEVANCE: Gastrostomy tubes appear to be safe and effective for improving nutritional status of dogs with renal failure.