Search Results

Abstract

Objective—To determine the efficacy of trilostane, a 3β-hydroxysteroid dehydrogenase inhibitor, in dogs with pituitary-dependent hyperadrenocorticism (PDH).

Animals—11 dogs with PDH.

Procedure—The initial dose of trilostane was 30 mg, PO, q 24 h for dogs that weighed < 5 kg and 60 mg, PO, q 24 h for dogs that weighed ≥ 5 kg. A CBC count, serum biochemical analyses, urinalysis, ACTH stimulation test, and ultrasonographic evaluation of the adrenal glands were performed in each dog 1, 3 to 4, 6 to 7, 12 to 16, and 24 to 28 weeks after initiation of treatment.

Results—All dogs responded well to treatment. All had reductions in polyuria-polydipsia and panting and an increase in activity. Polyphagia decreased in 9 of 10 dogs, and 9 of 11 dogs had improvement of coat quality and skin condition. Concentration of cortisol after ACTH stimulation significantly decreased by 1 week after initiation of treatment. After treatment for 6 months, clinical signs resolved in 9 dogs. In the other 2 dogs, marked clinical improvement was reported for 1 dog, and moderate improvement was reported in the other dog. Ultrasonographically, there was a considerable change in the parenchyma and an increase in size of the adrenal glands. Adverse effects consisted of 1 dog with transient lethargy and 1 dog with anorexia.

Conclusions and Clinical Relevance—Trilostane is an efficacious and safe medication for treatment of dogs with PDH. Additional studies in a larger group of dogs and characterization of progressive changes in adrenal glands are needed. (Am J Vet Res 2002;63:506–512).

Abstract

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. (Am J Vet Res 2003;64:1161–1166)

Abstract

Objective—To evaluate owner compliance with longterm home monitoring of blood glucose concentrations in diabetic cats and assess the influence of home monitoring on the frequency of reevaluation of those cats at a veterinary hospital.

Design—Retrospective study.

Animals—26 cats with diabetes mellitus.

Procedure—Medical records of diabetic cats for which home monitoring was undertaken were reviewed, and owners were contacted by telephone. Signalment, laboratory test results, insulin treatment regimen, details of home monitoring, clinical signs during treatment, frequency of follow-up examinations, and survival times were evaluated.

Results—Monitoring of cats commenced within 12 weeks (median, 3 weeks) after initial evaluation; 8 owners were unable to perform home monitoring, and 1 cat was euthanatized after 1 week. In 17 cats, duration of home monitoring was 4.8 to 46.0 months (median, 22.0 months); 6 cats died after 7.0 to 18.0 months (median, 13.0 months). In 11 cats, home monitoring was ongoing at completion of the study (12.0 to 46.0 months' duration). Fourteen owners completed blood glucose curves every 2 to 4 weeks. Cats managed with home monitoring received higher dosages of insulin, compared with cats that were not monitored. Four of 17 cats managed by home monitoring had transient resolution of diabetes mellitus for as long as 1 year. Home monitoring did not affect the frequency of reevaluation at the veterinary hospital.

Conclusions and Clinical Relevance—Owner compliance with long-term home monitoring appeared to be satisfactory, and home monitoring did not affect the frequency of reevaluation of patients by veterinarians. (J Am Vet Med Assoc 2004;225:261–266)

Abstract

Objective—To evaluate the effect of trilostane on serum concentrations of aldosterone, cortisol, and potassium in dogs with pituitary-dependent hyperadrenocorticism (PDH), compare the degree of reduction of aldosterone with that of cortisol, and compare aldosterone concentrations of healthy dogs with those of dogs with PDH.

Animals—17 dogs with PDH and 12 healthy dogs.

Procedure—For dogs with PDH, the initial dose of trilostane was selected in accordance with body weight. A CBC count, serum biochemical analyses, and ACTH stimulation tests were performed in each dog. Dogs were evaluated 1, 3 to 4, 6 to 8, and 10 to 12 weeks after initiation of treatment. Healthy dogs were evaluated only once.

Results—Serum aldosterone concentrations before ACTH stimulation did not change significantly after initiation of treatment with trilostane. At each evaluation after initiation of treatment, serum aldosterone concentrations after ACTH stimulation were significantly lower than corresponding concentrations before initiation of treatment. The overall effect of trilostane on serum aldosterone concentration was less pronounced than the effect on serum cortisol concentration. Median potassium concentrations increased slightly after initiation of treatment with trilostane. Dogs with PDH had significantly higher serum aldo sterone concentrations before and after ACTH stimulation than healthy dogs.

Conclusions and Clinical Relevance—Treatment with trilostane resulted in a reduction in serum cortisol and aldosterone concentrations in dogs with PDH, although the decrease for serum aldosterone concentration was smaller than that for serum cortisol concentration. There was no correlation between serum concentrations of aldosterone and potassium during treatment. (Am J Vet Res 2004;65:1245–1250)

Abstract

OBJECTIVE To evaluate the effects of storage conditions and duration on cobalamin concentration in serum samples from dogs and cats.

DESIGN Experiment.

SAMPLE Serum samples from 9 client-owned cats and 9 client-owned dogs.

PROCEDURES Serum harvested from freshly obtained blood samples was separated into 11 aliquots/animal. One aliquot (baseline sample) was routinely transported in light-protected tubes to the laboratory for cobalamin assay; each of the remaining aliquots was stored in a refrigerator (6°C; n = 5) or at room temperature (20°C) with exposure to daylight (5) for 24, 48, 72, 96, or 120 hours. Aliquots were subsequently wrapped in aluminum foil, frozen (−20°C), and then transported to the laboratory for measurement of cobalamin concentration, all in the same run. Percentage decrease in cobalamin concentration from baseline was analyzed by means of linear mixed modeling.

RESULTS No differences in cobalamin values were identified between cats and dogs; therefore, data for both species were analyzed together. Median baseline serum cobalamin concentration was 424 ng/L (range, 178 to 1,880 ng/L). Values for serum samples stored with daylight exposure at room temperature were significantly lower over time than were values for refrigerated samples. Although values for refrigerated samples did not decrease significantly from baseline values over time, values for the other storage condition did; however, the mean percentage decrease for serum samples stored at room temperature was small (0.14%/h; 95% confidence interval, 0.07% to 0.21%/h).

CONCLUSIONS AND CLINICAL RELEVANCE Overall, serum cobalamin concentration appeared stable for 5 days when feline and canine serum samples were refrigerated at 6°C. The effect of light and room temperature on serum cobalamin concentration, although significant, was quite small for samples stored with these exposures for the same 5-day period.

Abstract

Objective—To evaluate the use of high-resolution manometry (HRM) in awake and sedated dogs and to assess potential effects of a standard sedation protocol.

Animals—22 Beagles.

Procedures—An HRM catheter with 36 pressure sensors was inserted intranasally in each dog. After an adaption period of 5 minutes, each set of measurements included 5 swallows of a liquid and 5 swallows of a solid bolus. Measurements were repeated 30 minutes after IM administration of buprenorphine and acepromazine.

Results—HRM was successfully performed in 14 dogs. Data sets of 8 dogs were adequate for analysis. For the upper esophageal sphincter, median values of baseline pressure, residual pressure, relaxation time to nadir, and relaxation duration were determined for awake and sedated dogs for liquid and solid swallows. For the tubular portion of the esophagus, median values of peristaltic contractile integral, bolus transit time, and contractile front velocity were determined for awake and sedated dogs for liquid and solid swallows. For the lower esophageal sphincter, median values of baseline pressure and residual pressure were determined for awake and sedated dogs for liquid and solid swallows. Significant differences (awake vs sedated) were found for the upper esophageal sphincter residual pressure (liquid swallows), relaxation time to nadir (liquid swallows), bolus transit time (solid swallows), and contractile front velocity (solid swallows).

Conclusions and Clinical Relevance—HRM was feasible for evaluation of esophageal function in most awake dogs. Although sedation in uncooperative patients may minimally influence results of some variables, an overall assessment of swallowing should be possible.

Abstract

Objective—To evaluate the effects of cisapride and metoclopramide hydrochloride administered orally on the lower esophageal sphincter (LES) resting pressure in awake healthy dogs.

Animals—6 adult Beagles.

Procedures—Each dog was evaluated after administration of a single dose of cisapride (0.5 mg/kg), metoclopramide (0.5 mg/kg), or placebo (empty gelatin-free capsule) in 3 experiments performed at 3-week intervals. To measure LES pressure, a high-resolution manometry catheter equipped with 40 pressure sensors spaced 10 mm apart was used. For each experiment, LES pressure was recorded during a 20-minute period with a virtual electronic sleeve emulation before treatment (baseline) and at 1, 4, and 7 hours after drug or placebo administration. A linear mixed-effects model was used to test whether the 3 treatments affected LES pressure differently.

Results—In the cisapride, metoclopramide, and placebo experiments, median baseline LES pressures were 29.1, 30.5, and 29.0 mm Hg, respectively. For the cisapride, metoclopramide, and placebo treatments, median LES pressures at 1 hour after administration were 44.4, 37.8, and 36.6 mm Hg, respectively; median LES pressures at 4 hours after administration were 50.7, 30.6, and 31.1 mm Hg, respectively; and median LES pressures at 7 hours after administration were 44.3, 28.5, and 33.3 mm Hg, respectively. The LES pressures differed significantly only between the placebo and cisapride treatments.

Conclusions and Clinical Relevance—Results suggested that orally administered cisapride may be of benefit in canine patients for which an increase in LES pressure is desirable, whereas orally administered metoclopramide did not affect LES resting pressures in dogs.

Abstract

Objective—To evaluate day-to-day variability in blood glucose curves (BGCs) generated at home and at the clinic for cats with diabetes mellitus.

Design—Prospective study.

Animals—7 cats with diabetes mellitus.

Procedures—BGCs generated at home on 2 consecutive days and within 1 week at the clinic were obtained twice. On each occasion, insulin dose, amount of food, and type of food were consistent for all 3 BGCs. Results of curves generated at home were compared with each other and with the corresponding clinic curve.

Results—Differences between blood glucose concentration determined after food was withheld (fasting), nadir concentration, time to nadir concentration, maximum concentration, and mean concentration during 12 hours had high coefficients of variation, as did the difference between fasting blood glucose and nadir concentrations and area under the curve of home curves. Differences between home curve variables were not smaller than those between home and clinic curves, indicating large day-to-day variability in both home and clinic curves. Evaluation of the paired home curves led to the same theoretical recommendation for adjustment of insulin dose on 6 of 14 occasions, and evaluation of home and clinic curves resulted in the same recommendation on 14 of 28 occasions. Four of the 6 paired home curves in cats with good glycemic control and 2 of the 8 paired home curves in cats with poor glycemic control led to the same recommendation.

Conclusions and Clinical Relevance—Considerable day-to-day variability was detected in BGCs generated at home. Cats with good glycemic control may have more reproducible curves generated during blood collection at home than cats with poorer control.

Abstract

Objective—To investigate agreement of a feline pancreas–specific lipase assay and a colorimetric lipase assay with a 1,2-o-dilauryl-rac-glycero-3-glutaric acid-(6′-methylresorufin) ester (DGGR) substrate with results of pancreatic ultrasonography in cats with suspicion of pancreatitis.

Design—Retrospective case series.

Animals—161 client-owned cats with suspicion of pancreatitis.

Procedures—Feline pancreas–specific lipase concentration and DGGR lipase activity were measured from the same blood sample in cats undergoing investigation for pancreatitis, with < 24 hours between ultrasonography and lipase determinations. Ultrasonographic variables evaluated were ultrasonographic diagnosis of pancreatitis, enlargement, margins, echogenicity, mesenteric echogenicity, peripancreatic free fluid, cysts, masses, and common bile and pancreatic duct dilation. Agreement was assessed by use of the Cohen κ coefficient.

Results—Agreement between the lipase assays was substantial (κ = 0.703). An ultrasonographic diagnosis of pancreatitis had fair agreement with feline pancreas–specific lipase concentration > 5.4 μg/L (κ = 0.264) and DGGR lipase activity > 26 U/L (κ = 0.221). The greatest agreement between feline pancreas–specific lipase concentration > 5.4 μg/L and DGGR lipase activity > 26 U/L was found for a hypoechoic and mixed-echoic (κ = 0.270 and 0.266, respectively), hypoechoic (κ = 0.261 and 0.181, respectively), and enlarged (κ = 0.218 and 0.223, respectively) pancreas.

Conclusions and Clinical Relevance—Agreement between pancreatic ultrasonography and lipase assay results was only fair. It remains unknown whether lipase results or pancreatic ultrasonography constitutes the more accurate test for diagnosing pancreatitis; therefore, results of both tests need to be interpreted with caution.

Abstract

Objective—To evaluate whether determination of parathyroid gland size by use of ultrasonography is helpful in differentiating acute renal failure (ARF) from chronic renal failure (CRF) in dogs.

Design—Prospective study.

Animals—20 dogs with renal failure in which serum creatinine concentration was at least 5 times the upper reference limit. Seven dogs had ARF, and 13 dogs had CRF. Twenty-three healthy dogs were used as controls.

Procedure—Dogs were positioned in dorsal recumbency for ultrasonographic examination of the ventral portion of the neck, A 10-MHz linear-array high-resolution transducer was used. The size of the parathyroid gland was determined by measuring the maximal length of the gland on the screen when it was imaged in longitudinal section. For comparison among groups, the longest linear dimension of any of the parathyroid glands of each dog was used.

Results—Size of the parathyroid glands in the control dogs varied from 2.0 to 4.6 mm (median, 3.3 mm). In the dogs with ARF, gland size ranged from 2.4 to 4.0 mm (median, 2.7), which was not significantly different from controls. In dogs with CRF, the glands were more distinctly demarcated from the surrounding thyroid tissue, than those of controls and dogs with ARF. Sizes ranged from 3.9 to 8.1 mm (median, 5.7 mm), which was significantly larger, compared with controls and dogs with ARF.

Conclusion and Clinical Relevance—In dogs with severe azotemia, ultrasonographic examination of the parathyroid glands was helpful in differentiating ARF from CRF. Size of the parathyroid glands appeared to be related to body weight. (J Am Vet Med Assoc 2000;217:1849–1852)