Search Results

Abstract

Objective—To compare glomerular filtration rate (GFR) measured via urinary clearance of inulin (UCI) with plasma clearance of technetium Tc 99m pentetate (^99mTc-pentetate) and creatinine in dogs.

Animals—6 healthy Beagles and 18 Beagles with reduced renal function.

Procedure—13 blood samples were obtained between 5 and 600 minutes after IV bolus injections of ^99mTc-pentetate and creatinine. Plasma clearance of ^99mTc-pentetate was computed on the basis of 1, 2, or 13 samples, and plasma clearance of creatinine was computed on the basis of 2, 5, or 13 samples. During plasma clearance procedures, constant IV infusion of carboxyl carbon 14 inulin was begun and UCI was determined in urine collected from 90 to 120, 120 to 180, and 180 to 240 minutes. Clearance procedures were repeated in 12 dogs to evaluate reproducibility of results.

Results—Significant association between UCI and plasma clearance was determined via all methods. However, plasma clearances were moderately to markedly different from UCI, depending on test substance, GFR, and sample numbers used for plasma clearance computations. Comparisons were particularly discordant when some methods of limiting samples were used to define plasma clearance.

Conclusions and Clinical Relevance—Values derived from plasma clearance methods for ^99mTc-pentetate and creatinine were not interchangeable with UCI results, which raises questions about their reliability as clinical research tools for measurement of GFR. Plasma clearance methods that are relative indices of renal function should not be interpreted as accurate measures of GFR without validation. (Am J Vet Res 2005;66:1046–1055)

Abstract

Objective—To determine owner impressions of 3 premium canine diets when factors such as price and retail source were removed; to compare body condition scores (BCSs) assigned by owners versus a veterinarian; and to determine consistency of owner impressions of diets when owners were not informed that they were feeding the same diet during 2 consecutive periods.

Design—Randomized controlled trial.

Animals—44 healthy adult dogs.

Procedure—During the initial 12 months of the study, dogs were each fed 3 premium diets for 4 months in random order. After feeding each diet for 1 and 4 months, owners completed questionnaires regarding palatability of the diet; the dog's attitude, energy level, fecal consistency, frequency of defecation, hair coat quality, and BCS; and whether they would feed the diet if available commercially. During the last 4 months of the study, owners fed the same diet they had been feeding during the previous 4 months.

Results—Scores for most variables did not differ among diets. However, mean BCS assigned by owners was significantly lower than mean BCS assigned by an investigator, with a moderate correlation between scores. When asked at the end of the third and fourth study periods whether they would consider feeding the diet long-term, 12 of the 44 (27%) owners gave inconsistent responses.

Conclusions and Clinical Relevance—Results indicate that when unaware of retail price and source, owners have similar impressions of 3 premium diets fed to healthy adult dogs, suggesting that factors other than the diets themselves may affect owner impressions. Owners also underestimate their dog's BCS. (J Am Vet Med Assoc 2005;227:1931–1936)

Abstract

Objective—To determine whether the angiotensin converting enzyme inhibitor enalapril would lower systemic arterial and glomerular capillary pressure and reduce the magnitude of renal injury in a canine model of renal insufficiency.

Animals—18 adult dogs that had renal mass reduced by partial nephrectomy.

Procedure—After surgical reduction of renal mass and baseline measurements, dogs in 2 equal groups received either placebo (group 1) or enalapril (0.5 mg/kg, PO, q 12 h; group 2) for 6 months.

Results—Values for systemic mean arterial blood pressure determined by indirect and direct measurement after 3 and 6 months of treatment, respectively, were significantly lower in group 2 than in group 1. During treatment, monthly urine protein-to-creatinine ratios were consistently lower in group 2 than in group 1, although values were significantly different only at 3 months. At 6 months, significant reduction in glomerular capillary pressure in group 2 was detected, compared with group 1, but glomerular filtration rate in group 2 was not compromised. Glomerular hypertrophy, assessed by measurement of planar surface area of glomeruli, was similar in both groups. Glomerular and tubulointerstitial lesions were significantly less in group 2, compared with group 1.

Conclusions and Clinical Relevance—Data suggest that inhibition of angiotensin converting enzyme was effective in modulating progressive renal injury, which was associated with reduction of glomerular and systemic hypertension and proteinuria but not glomerular hypertrophy. Inhibition of angiotensin converting enzyme may be effective for modulating progression of renal disease in dogs. (Am J Vet Res 2003;64:321–327)

Abstract

Objective—To determine whether pharmacokinetic analysis of data derived from a single IV dose of iohexol could be used to predict creatinine clearance and evaluate simplified methods for predicting serum clearance of iohexol with data derived from 2 or 3 blood samples in clinically normal foals.

Animals—10 healthy foals.

Procedure—Serum disposition of iohexol and exogenous creatinine clearance was determined simultaneously in each foal (5 males and 5 females). A 3-compartment model of iohexol serum disposition was selected via standard methods. Iohexol clearance calculated from the model was compared with creatinine clearance. Separate limited-sample models were created with various combinations of sample times from the terminal slope of the plasma versus time profile for iohexol. Correction factors were determined for the limited-sample models, and iohexol clearance calculated via each method was compared with exogenous creatinine clearance by use of method comparison techniques.

Results—Mean exogenous creatinine clearance was 2.17 mL/min/kg. The disposition of iohexol was best described by a 3-compartment open model. Mean clearance value for iohexol was 2.15 mL/min/kg and was not significantly different from mean creatinine clearance. A method for predicting serum iohexol clearance based on a 2-sample protocol (3- and 4-hour samples) was developed.

Conclusions and Clinical Relevance—Iohexol clearance can be used to predict exogenous creatinine clearance and can be determined from 2 blood samples taken after IV injection of iohexol. Appropriate correction factors for adult horses and horses with abnormal glomerular filtration rate need to be determined. (Am J Vet Res 2003;64:1486–1490)

Abstract

Objective—To determine effects of an extract of Serenoa repens on dogs with prostatic hyperplasia.

Animals—20 mature male dogs with benign prostatic hyperplasia.

Procedure—Dogs were assigned to 3 comparable groups on the basis of prostatic volume per kg of body weight and degree of prostatic hyperplasia determined histologically. Dogs in 2 groups were treated for 91 days (8 received 500 mg, PO, q 8 h [1,500 mg/d], and 6 received 100 mg, PO, q 8 h [300 mg/d]). The control group of 6 dogs did not receive medication. Effects of treatment on prostatic volume, prostatic weight, prostatic histologic characteristics, radiographic and ultrasonographic assessment of prostatic size, results of CBC, serum biochemical analyses, and urinalysis, serum testosterone concentration, and semen characteristics were determined. At the termination of the study, all dogs were euthanatized, and necropsies were performed. Investigators conducting tests and interpreting results were not aware of treatment group of each dog.

Results—Treatment did not affect prostatic weight, prostatic volume, or prostatic histologic scores, libido, semen characteristics, radiographs of the caudal portion of the abdomen, prostatic ultrasonographs, or serum testosterone concentrations. Results of CBC, serum biochemical analyses or urinalysis, and body weights did not change during treatment.

Conclusions and Clinical Relevance—Treatment with an extract of S repens for 91 days did not significantly affect the prostate gland of dogs. Adverse effects were not evident. Although products containing extracts of S repens are widely advertised for men with prostatic hyperplasia, beneficial or harmful effects of this plant extract were not found in dogs with prostatic hyperplasia. (Am J Vet Res 2000;61:880–885)