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  • Author or Editor: Larry D. Cowgill x
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Abstract

Objective—To characterize serologic and clinical features and outcome of dogs with leptospirosis that were treated conservatively (ie, medical management alone) or with hemodialysis.

Design—Retrospective study.

Animals—36 dogs with leptospirosis.

Procedure—History; results of physical examinations, ultrasonography, and serologic, hematologic, and serum biochemical analyses; time to resolution of azotemia; and outcome were obtained from medical records. Dogs were treated conservatively (n = 22) or with hemodialysis (14).

Results—Between 1990 and 1998, amount of rainfall was positively correlated with number of cases of leptospirosis identified per year. Serum antibodies against 6 Leptospira serovars were measured, and titers were highest to Leptospira pomonain 16 (44%) dogs, L bratislava in 9 (25%) dogs, and L hardjo in 1 (3%) dog. Eight (22%) dogs had equally high titers to L pomona and L bratislava, 1 (3%) had equally high titers to L grippotyphosa and L canicola, and 1 (3%) had high titers to L grippotyphosa, L pomona, L canicola, and L bratislava. During initial evaluation, all dogs were azotemic. Thirty (83%) dogs survived, including 12 of 14 (86%) dogs treated with hemodialysis and 18 of 22 (82%) treated conservatively. Serum creatinine concentration was similar in both groups after resolution of clinical signs.

Conclusion and Clinical Relevance—Infection with L pomona and L bratislava was recognized as a cause of leptospirosis in dogs, and resulted in development of acute renal failure with various degrees of azotemia. Prognosis for dogs with mild to moderate azotemia was good with conservative treatment, whereas treatment with hemodialysis appeared to improve prognosis for dogs with severe azotemia. (J Am Vet Med Assoc 2000;216:371–375)

Full access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE To compare dialysate sodium concentration and patient plasma sodium concentration of dogs during intermittent hemodialysis treatments.

SAMPLE 211 intermittent hemodialysis treatments performed on 40 client-owned dogs for the management of dialysis-dependent uremia.

PROCEDURES Medical records were reviewed to determine the plasma sodium concentration of each dog before and after routine hemodialysis treatments. Associations between detected changes in plasma sodium concentration and dialysate sodium concentration were evaluated by use of Spearman rank correlations and linear regression analysis.

RESULTS Significant linear correlations were found between the dialysate sodium concentration and patient sodium concentration. The starting dialysate-to-patient sodium gradient was associated with the strongest correlation to the change in patient sodium concentration at the end of the dialysis session. Modest correlations existed between the dialysate sodium concentration and postdialysis patient sodium concentration as well as between the predialysis dialysate-to-patient sodium gradient and postdialysis dialysate-to-patient sodium gradient.

CONCLUSIONS AND CLINICAL RELEVANCE The dialysate sodium concentration was correlated with the patient sodium concentration in dogs, and the dialysate-to-patient sodium gradient could be used to further refine this association to predict the postdialysis patient sodium concentration and potentially manage dysnatremia during hemodialysis. Prospective studies should be performed to determine how these associations can be used to correct aberrations as well as to avoid unwanted alterations in patient sodium concentrations.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate quantification of the amount of carbamylated hemoglobin (CarbHb), using capillary electrophoresis (CE) and a new dynamic capillary coating system to separate hemoglobin derivatives, and to assess the use of CarbHb amounts to evaluate long-term urea exposure and differential diagnoses of azotemia in dogs.

Animals—8 dogs with renal failure, 2 dogs with diabetes mellitus, and 7 control dogs.

Procedure—Optimal analytic conditions for separation of CarbHb and other hemoglobin derivatives in blood samples obtained from dogs were determined, using a commercial analysis system developed for the detection of glycohemoglobin Hb A1c (GlycHb) in human blood samples. Relative content of hemoglobin derivatives in blood from 10 dogs with renal failure or endocrine diseases were compared with values for 7 dogs without renal or endocrine diseases.

Results—Satisfactory resolution of hemoglobin derivatives was obtained, which permitted identification and quantitation of the amount of CarbHb as a percentage of the total amount of hemoglobin. Normal or increased amounts of GlycHb did not interfere with CarbHb analysis. Dogs with chronic renal failure had considerably higher peak amounts of CarbHb than dogs with acute renal failure, a dog with chronic renal failure that was treated by use of hemodialysis, or dogs without renal disease.

Conclusions and Clinical Relevance—Amounts of CarbHb in blood samples obtained from dogs can be readily quantified by use of capillary electrophoresis. Assessment of the amount of CarbHb can be used to facilitate evaluation of the cause of azotemia in dogs. (Am J Vet Res 2001;62:1302–1306)

Full access
in American Journal of Veterinary Research

Objective—

To determine the prevalence of hypergastrinemia in cats with naturally developing chronic renal failure (CRF) and the correlation between gastrin concentration in plasma and severity of CRF.

Design—

Cohort study.

Animals—

30 cats with naturally developing CRF and 12 clinically normal control cats.

Procedure—

Gastrin concentrations in plasma were determined by double-antibody radioimmunoassay of blood samples obtained from cats after food was withheld 8 hours. Concentrations were compared, using a nonparametric Kruskal-Wallis ANOVA.

Results—

18 cats with CRF had high gastrin concentrations (median, 45 pg/ml; range, < 18 to > 1,333 pg/ml), compared with those for control cats (< 18 pg/ml). Prevalence of hypergastrinemia increased with severity of renal insufficiency. Three of 9 cats with mild CRF, 6 of 11 cats with moderate CRF, and 9 of 10 cats with severe CRF had high gastrin concentrations. Gastrin concentrations were significantly different between control cats and cats with CRF, regardless of disease severity.

Clinical Implications—

The potential role of high concentrations of gastrin on gastric hyperacidity, uremic gastritis, bleeding from the gastrointestinal tract, and associated clinical signs of hypergastrinemia (eg, anorexia and vomiting) may justify use of histamine2-receptor antagonists or proton pump inhibitors to suppress gastric acid secretion in cats with CRF that have these clinical signs. (J Am Vet Med Assoc 1998;213:826-828)

Free access
in Journal of the American Veterinary Medical Association

Objective

To compare blood pressure and heart rate measurements performed in a veterinary clinic to similar measurements performed in a dog's home.

Design

Prospective study.

Animals

14 client-owned, clinically normal dogs.

Procedure

Sequential blood pressure and heart rate measurements were recorded from the metatarsus and metacarpus of conscious dogs by indirect oscillometry. Measurements were performed in the dogs' homes and were repeated in a veterinary clinic. Blood pressures and heart rate were derived from 7 serial estimates over 8 to 10 minutes. Statistical differences between the home and clinic and between recording sites were calculated.

Results

Systolic, diastolic, and mean blood pressure and heart rate measurements obtained from the metatarsus and metacarpus in the dogs' homes were significantly lower than measurements from the metatarsus in the clinic, but were similar to measurements from the metacarpus in the clinic. Significant differences were not found between blood pressure measurements from the metatarsus and metacarpus in the dogs' homes, but systolic and mean blood pressure and heart rate measurements from the metacarpus in the clinic were significantly lower than measurements from the metatarsus. Whereas all dogs had normal blood pressure in their homes, 5 of 14 dogs had transient hypertension (systolic pressure > 165 mm of Hg or diastolic pressure > 95 mm of Hg) in the clinic.

Clinical Implications

Blood pressure and heart rate measurements obtained in the clinic initially overestimate comparable measurements in a dog's home. The differences are best explained by transient autonomic responses to the stress of the clinic. Blood pressure must be measured by use of standardized techniques on dogs acclimated to the clinic environment.

Free access
in Journal of the American Veterinary Medical Association

Objective

To describe 7 cases of acute postoperative azotemia in dogs and to examine by use of a case-control study the possible association between this complication and administration of nafcillin.

Design

Retrospective and case-control study.

Animals

7 case dogs and 28 matched control dogs.

Procedure

Cases of acute renal failure or acute renal insufficiency were identified by retrospective study of records of dogs treated between July 1, 1992, and Feb 28, 1995, and from information received from a practitioner. A random sample of records of dogs undergoing invasive procedures between Dec 1, 1992, and Nov 30, 1993, was examined to determine the prevalence of nafcillin use. Each case dog was matched with 4 control dogs, and data were subjected to logistic regression analysis, employing exact conditional inference on the parameter estimates.

Results

Case dogs were between 1 and 9 years old and weighed between 21 and 60 kg. Preoperatively, none of the dogs had a history of renal disease, and BUN concentrations, hematocrit, and plasma protein concentrations were within reference ranges. Postoperatively, each dog became azotemic and had clinical signs consistent with uremia. Hyponatremia was recorded in 6 case dogs. One dog did not respond to treatment and was euthanatized. Two dogs had persistent isosthenuria, and 4 dogs recovered. Nafcillin was used in approximately 502 of 2,184 (23%) dogs that underwent invasive procedures between Dec 1, 1992, and Nov 30, 1993. The use of nafcillin ceased on Nov 30, 1993, and no further cases were recorded in the following 15 months. In the case-control study, the only factor that was significantly associated with the occurrence of acute postoperative azotemia was administration of nafcillin.

Clinical Implications

Intraoperative use of nafcillin may be associated with development of acute postoperative azotemia in dogs. (J Am Vet Med Assoc 1996; 208:1043–1047)

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To compare plasma clearance of inulin and iohexol determined by use of 9 plasma samples for evaluation of glomerular filtration rate in dogs and to evaluate limited-sample approaches for evaluation of plasma clearance of these markers.

Animals—43 dogs of various breeds that weighed between 5.5 and 63 kg and that had various degrees of renal function.

Procedures—9 plasma samples were obtained from each dog at 5 minutes to 6 hours after IV bolus injection of iohexol and inulin. Clearance was calculated by use of results for all 9 samples (ie, reference method). Results for 3 limited-sample strategies for determination of plasma clearance of iohexol and inulin were compared with results for the reference method.

Results—Mean clearance of inulin and iohexol for the reference method was 2.72 and 2.48 mL/min/kg, respectively. The mean difference between clearance of these 2 markers for the reference method was 0.24 mL/min/kg. In general, use of the limited-sample strategies yielded clearance values similar to those for the reference method. More accurate estimates of clearance were obtained for iohexol than for inulin by use of the limited-sample methods.

Conclusions and Clinical Relevance—Use of iohexol and inulin yielded similar but not identical results for plasma clearance. Accuracy for limited-sample methods would be acceptable for many clinical and research situations. (Am J Vet Res 2010;71:1100–1107)

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To determine whether ultrasonographic features in dogs with protein-losing nephropathy (PLN) were associated with renal biopsy findings and compare corticomedullary ratios between dogs with PLN versus non-renal disease.

ANIMALS

71 dogs with PLN and 33 dogs without renal disease.

PROCEDURES

Medical records and archived ultrasonographic images for dogs with PLN that underwent renal biopsy between 2008 and 2018 were reviewed. Corticomedullary ratios were measured.

RESULTS

In dogs with PLN, median serum creatinine and BUN concentrations and urine-protein-to-creatinine-ratio prior to renal biopsy were 3.4 mg/dL (interquartile range [IQR], 1.2 to 5.3 mg/dL), 80 mg/dL (IQR, 28 to 105 mg/dL), and 11.4 (IQR, 6.4 to 18.3), respectively. Histologic abnormalities within the tubulointerstitial space were associated with cortical echogenicity. Gastric wall thickness > 5 mm was associated with a histologic diagnosis of acute glomerular disease. Dogs with immune complex–mediated glomerular disease were more likely to have abnormal gastric mural architecture. Other ultrasonographic features of the kidneys, liver, and stomach and the presence of ascites did not help to differentiate immune complex–mediated from non-immune complex–mediated glomerular disease, acute from chronic disease, or amyloid from non-amyloid disease or distinguish whether tubulointerstitial disease was present or absent. Median left corticomedullary ratio for 66 dogs with PLN (1.2) was significantly higher than that for the 33 dogs without renal disease (1.0).

Clinical Relevance

Ultrasonographic features were poorly associated with specific pathological disorders in dogs with PLN. In this study, the corticomedullary ratio was higher in dogs with PLN, indicating the presence of cortical thickening, but the clinical relevance is unknown.

Open access
in American Journal of Veterinary Research

Abstract

Objective—To characterize the effect of maintenance hemodialysis on plasma amino acid concentrations and to quantitate free amino acid losses into the dialysate during hemodialysis in healthy dogs.

Animals—8 healthy adult dogs.

Procedure—Five dogs received hemodialysis treatments 3 times per week for 4 weeks. Plasma amino acid concentrations were evaluated once per week for 4 weeks in each of the 5 dogs prior to hemodialysis (time 0), 90 minutes during hemodialysis, and immediately after hemodialysis (180 minutes). Total free amino acid concentrations and plasma amino acid concentrations (time 0, 90 minutes, and 180 minutes) in the dialysate were evaluated in 3 dogs that received 1 hemodialysis treatment.

Results—Significant time versus week interactions with any plasma amino acid were not detected; however, significant decreases in all plasma amino acid concentrations measured were detected at the midpoint of dialysis (46 ± 2%) and at the end of each dialysis session (38 ± 2%). Mean (± SEM) total free amino acid loss into the dialysate was 2.7 ± 0.2 g or 0.12 g/kg of body weight.

Conclusions and Clinical Relevance—Hemodialysis is associated with significant alterations in plasma amino acid concentrations and loss of free amino acids into the dialysate. Loss of amino acids into the dialysate, coupled with protein calorie malnutrition in uremic patients, may contribute to depletion of amino acid stores.(Am J Vet Res 2000;61:869–873)

Full access
in American Journal of Veterinary Research