Search Results

Abstract

Objective—To develop and analytically validate a radioimmunoassay (RIA) for the quantification of canine calprotectin (cCP) in serum and fecal extracts of dogs.

Sample Population—Serum samples (n = 50) and fecal samples (30) were obtained from healthy dogs of various breeds and ages.

Procedures—A competitive, liquid-phase, double-antibody RIA was developed and analytically validated by assessing analytic sensitivity, working range, linearity, accuracy, precision, and reproducibility. Reference intervals for serum and fecal cCP concentrations were determined.

Results—Sensitivity and upper limit of the working range were 29 and 12,774 μg/L for serum and 2.9 and 1,277.4 μg/g for fecal extracts, respectively. Observed-to-expected ratios for serial dilutions of 6 serum samples and 6 fecal extracts ranged from 95.3% to 138.2% and from 80.9% to 118.1%, respectively. Observed-to-expected ratios for spiking recovery for 6 serum samples and 6 fecal extracts ranged from 84.6% to 121.5% and from 80.3% to 132.1%, respectively. Coefficients of variation for intra-assay and interassay variability were < 3.9% and < 8.7% for 6 serum samples and < 8.5% and < 12.6% for 6 fecal extracts, respectively. Reference intervals were 92 to 1,121 μg of cCP/L for serum and < 2.9 to 137.5 μg of cCP/g for fecal extracts.

Conclusions and Clinical Relevance—The RIA described here was analytically sensitive, linear, accurate, precise, and reproducible for the quantification of cCP in serum and fecal extracts. This assay should facilitate research into the clinical use of serum and fecal cCP measurements in dogs with inflammatory bowel disease.

Abstract

Objective—To develop and analytically validate a gas chromatography–mass spectrometry (GC-MS) method for the quantification of lactulose, rhamnose, xylose, 3-O-methylglucose, and sucrose in canine serum.

Sample Population—Pooled serum samples from 200 dogs.

Procedures—Serum samples spiked with various sugars were analyzed by use of GC-MS. The method was analytically validated by determination of dilutional parallelism, spiking recovery, intra-assay variability, and interassay variability.

Results—Standard curves ranging from 0.5 to 500 mg/L for each sugar revealed a mean r ² of 0.997. The lower detection limit was 0.03 mg/L for lactulose, rhamnose, xylose, and methylglucose and 0.12 mg/L for sucrose. The observed-to-expected ratios for dilutional parallelism had a mean ± SD of 105.6 ± 25.4% at dilutions of 1:2, 1:4, and 1:8. Analytic recoveries for the GC-MS assays of sugars ranged from 92.1% to 124.7% (mean ± SD, 106.2 ± 13.0%). Intra-assay coefficients of variation ranged from 6.8% to 12.9% for lactulose, 7.1% to 12.8% for rhamnose, 7.2% to 11.2% for xylose, 8.9% to 11.5% for methylglucose, and 8.9% to 12.0% for sucrose. Interassay coefficients of variation ranged from 7.0% to 11.5% for lactulose, 6.4% to 9.4% for rhamnose, 6.8% to 13.2% for xylose, 7.0% to 15.9% for methylglucose, and 5.5% to 9.4% for sucrose.

Conclusions and Clinical Relevance—The GC-MS method described here was accurate, precise, and reproducible for the simultaneous measurement of sugar probes in canine serum.

Abstract

Objective—To test the hypothesis that intestinal pathologic changes are often concurrent with gastric pathologic changes in dogs and to characterize the historical, physical, clinicopathologic, imaging, and endoscopic findings in dogs with gastric histopathologic abnormalities.

Design—Retrospective case series.

Animals—67 dogs with gastric histopathologic abnormalities.

Procedures—Medical records from dogs that had undergone gastrotomy, gastroduodenoscopy, or gastroscopy between September 2002 and September 2007 were identified. Dogs were included in the study when histopathologic abnormalities were detected during evaluation of gastric tissue sections. History, clinical examination findings, results of diagnostic tests, diagnoses, treatments, and outcome were recorded for each dog.

Results—67 dogs with gastric histopathologic abnormalities were included in the study. The most frequent clinical sign recorded was vomiting (36/67 [53.7%] dogs). The most common biochemical abnormality recorded was panhypoproteinemia (27/64 [42.2%] dogs). Lymphoplasmacytic gastritis was the most frequent histopathologic finding recorded (34/67 [50.7%] dogs). For dogs in which both intestinal biopsy specimens and gastric biopsy specimens were collected, concurrent pathologic changes were recorded in 43 of 60 (71.7%) dogs.

Conclusions and Clinical Relevance—Results of this study suggested that intestinal pathologic changes are commonly concurrent in dogs with gastric pathologic changes. This supports the practice of collecting both gastric and duodenal biopsy specimens every time gastroduodenoscopy is performed. Lymphoplasmacytic gastritis was the most commonly recorded gastric histopathologic finding and was often of minimal or mild severity.

Abstract

Objective—To elucidate the relationship between plasma ammonia concentration and severity of hepatic encephalopathy and determine whether factors that precipitate hepatic encephalopathy in humans are associated with the presence of clinical signs of hepatic encephalopathy in dogs previously treated for the disease.

Design—Retrospective case series.

Animals—118 dogs with hepatic encephalopathy.

Procedures—The medical records database of a veterinary teaching hospital was searched for records of dogs in which hepatic encephalopathy was diagnosed between October 1, 1991, and September 1, 2014. Hepatic encephalopathy severity was graded on a 5-point scale, and the correlation between disease severity and plasma ammonia concentration was determined. Respective associations between hepatic encephalopathy and systemic inflammatory response syndrome, gastrointestinal hemorrhage, dietary indiscretion, constipation, furosemide treatment, azotemia, hypokalemia, hyponatremia, alkalosis, and hyperammonemia were assessed by Fisher exact tests followed by multivariable logistic regression.

Results—Severity of hepatic encephalopathy at hospital admission was not significantly correlated with plasma ammonia concentration. Dogs treated for hepatic encephalopathy prior to hospital admission were significantly less likely to have clinical signs of the disease at hospital admission, compared with dogs that were not treated for the disease (OR, 0.36; 95% confidence interval, 0.17 to 0.78). None of the putative precipitating factors for hepatic encephalopathy were significantly associated with the presence of clinical signs of the disease at hospital admission.

Conclusions and Clinical Relevance—Results indicated that hepatic encephalopathy treatment alleviated clinical signs of the disease. Further investigation is necessary to identify precipitating factors for hepatic encephalopathy in dogs. (J Am Vet Med Assoc 2015;247:176–183)

Abstract

Objective—To determine the prevalence of hypocobalaminemia in dogs with multicentric lymphoma and to investigate any relationship between serum cobalamin concentration and disease outcome.

Design—Cohort study.

Animals—58 dogs with multicentric lymphoma.

Procedures—Serum cobalamin concentrations were measured in 58 dogs with multicentric lymphoma. Clinical signs, stage, and immunophenotype for dogs with hypocobalaminemia were compared with those for dogs with serum cobalamin concentrations above the lower end of the reference range. Survival times for dogs undergoing a cyclic multidrug chemotherapy protocol (n = 53) were similarly compared. Serum cobalamin concentrations for treated dogs that died or were euthanized before day 60 were compared with those of dogs still alive at day 60.

Results—Serum cobalamin concentrations ranged from < 150 to 1,813 ng/L, with a median concentration of 401 ng/L. Nine of the 58 (16%) dogs had hypocobalaminemia (serum cobalamin concentration < 252 ng/L). Three of 9 dogs with hypocobalaminemia survived to at least day 60, compared with 40 of 44 (91%) dogs without hypocobalaminemia (serum cobalamin concentration ≥ 252 ng/L). Ten (10/53 [19%]) dogs undergoing a cyclic multidrug chemotherapy protocol died before day 60, and the median serum cobalamin concentration for these dogs (232 ng/L) was significantly lower than for those still alive at the end point of the study (556 ng/L).

Conclusions and Clinical Relevance—Hypocobalaminemia was relatively uncommon in this population of dogs with multicentric lymphoma, but was associated with a poor outcome. Serum cobalamin concentrations may provide prognostic information in dogs with multicentric lymphoma.

Abstract

Objective—To evaluate serum feline-specific pancreatic lipase immunoreactivity (fPLI) concentrations and abdominal ultrasonographic findings in cats with trauma resulting from high-rise syndrome.

Design—Prospective case series.

Animals—34 client-owned cats.

Procedures—From cats evaluated because of high-rise syndrome between March and October 2009, a blood sample was obtained for measurement of serum fPLI concentration within 12 hours after the fall and at 24, 48, and 72 hours after the first blood collection. Pancreatitis was diagnosed in cats with an fPLI concentration > 5.4 μg/L. Each cat had abdominal ultrasonography performed twice 48 hours apart, and pancreatic trauma was assessed via detection of pancreatic enlargement, hypoechoic or heteroechoic pancreatic parenchyma, hyperechoic mesentery, and peritoneal effusion. Cats were assigned 1 point for each abnormality present, and a cumulative score ≥ 3 was considered suggestive of traumatic pancreatitis.

Results—Traumatic pancreatitis was diagnosed in 9 and 8 cats on the basis of serum fPLI concentration and ultrasonographic findings, respectively. For cats with pancreatitis, fPLI concentration was significantly higher at 12 and 24 hours after the fall than at 48 and 72 hours after the fall, and serum fPLI concentration decreased as time after the fall increased. Significant agreement existed between the use of serum fPLI concentration and abdominal ultrasonography for the diagnosis of traumatic pancreatitis.

Conclusions and Clinical Relevance—Cats with high-rise syndrome often had serum fPLI concentrations > 5.4 μg/L within 12 hours after the fall, and concurrent evaluation of those cats via abdominal ultrasonography twice, 48 hours apart, improved detection of traumatic pancreatitis.

Abstract

Objective—To determine the optimal sample handling and processing conditions for the carbon 13 (¹³C)-labeled aminopyrine demethylation blood test (ADBT; phase 1) and determine the reference range for test results (phase 2) in apparently healthy dogs.

Animals—44 apparently healthy dogs (phase 1, 19 dogs; phase 2, 44 dogs).

Procedures—In phase 1, a blood sample from each dog was collected before and 45 minutes after (day 0) IV administration of ¹³C-labeled aminopyrine (2 mg/kg); aliquots were immediately transferred into tubes containing sodium heparin and hydrochloric acid (samples A and B), sodium heparin alone (samples C, D, and E), or sodium fluoride (sample F). Hydrochloric acid was added to samples C through F at days 7, 14, 21, and 21, respectively. The baseline and 45-minute samples' absolute ¹³C:¹²C ratios were determined via fractional mass spectrometry on day 0 (control sample A) or 21 (samples B through F) and used to calculate the percentage dose of ¹³C recovered in CO₂ extracted from samples (PCD). In phase 2, blood samples from each dog were collected into tubes containing sodium fluoride and processed within 3 weeks.

Results—Compared with the control sample value, PCDs for samples C through E differed significantly, whereas PCD in sample F did not. The ¹³C-ADBT–derived PCD reference range (central 95th percentile) for apparently healthy dogs was 0.08% to 0.2%.

Conclusions and Clinical Relevance—Glycolytic CO₂ production in canine blood samples collected during ¹³C-ADBTs was sufficiently inhibited by sodium fluoride to allow delayed sample analysis and avoid transportation of hydrochloric acid–treated samples.

Abstract

Objective—To measure serum calprotectin concentration in dogs with inflammatory bowel disease (IBD) before and after initiation of treatment and evaluate its correlation with a clinical scoring system (canine IBD activity index), serum canine C-reactive protein concentration, and severity of histopathologic changes.

Animals—34 dogs with idiopathic IBD and 139 healthy control dogs.

Procedures—From dogs with IBD, blood samples were collected immediately before (baseline) and 3 weeks after initiation of 1 of 2 treatments: prednisone (1 mg/kg, PO, q 12 h; n = 21) or a combination of prednisone and metronidazole (10 mg/kg, PO, q 12 h; 13). Blood samples were collected once from each of the control dogs. For all samples, serum calprotectin concentration was determined via radioimmunoassay.

Results—Mean serum calprotectin concentrations for dogs with IBD at baseline (431.1 μg/L) and 3 weeks after initiation of treatment (676.9 μg/L) were significantly higher, compared with that (219.4 μg/L) for control dogs, and were not significantly correlated with the canine IBD activity index, serum C-reactive protein concentration, or severity of histopathologic changes. The use of a serum calprotectin concentration of ≥ 296.0 μg/L as a cutoff had a sensitivity of 82.4% (95% confidence interval, 65.5% to 93.2%) and specificity of 68.4% (95% confidence interval, 59.9% to 76.0%) for distinguishing dogs with idiopathic IBD from healthy dogs.

Conclusions and Clinical Relevance—Serum calprotectin concentration may be a useful biomarker for the detection of inflammation in dogs, but the use of certain drugs (eg, glucocorticoids) appears to limit its clinical usefulness.

Abstract

Objective—To develop a fecal sample collection strategy and quantification method for measurement of fecal IgA concentrations in dogs.

Sample Population—Fecal samples from 23 healthy pet dogs of various breeds.

Procedures——Immunoglobulin A was extracted from fecal samples. An ELISA for the measurement of fecal IgA concentrations was established and analytically validated. Intraindividual variation of fecal IgA was determined by calculation of coefficients of variation. A sample collection strategy was developed on the basis of results of intraindividual variation of fecal IgA concentrations. A reference range for fecal IgA concentrations was determined.

Results—The method for extraction and quantification of fecal IgA was determined to be sufficiently sensitive, reproducible, accurate, and precise. On the basis of the intraindividual variability of our results, the determined fecal sample collection strategy required analysis of a total of 4 fecal samples/dog, with each fecal sample collected on 2 consecutive days with 28 days between sample collection periods (ie, days 1 and 2 followed by days 28 and 29). Reference range values for fecal IgA concentration were 0.22 to 3.24 mg/g of feces.

Conclusions and Clinical Relevance— Methods of fecal IgA extraction and quantification used in our study allow for identification of dogs with consistently low fecal IgA concentrations. Use of these techniques will enable future investigations into possible associations between low fecal IgA concentrations and signs of gastrointestinal disease in dogs.

Abstract

Objective—To evaluate the qualitative variation in bacterial microflora among compartments of the intestinal tract of dogs by use of a molecular fingerprinting technique.

Animals—14 dogs (similarly housed and fed identical diets).

Procedure—Samples of intestinal contents were collected from the duodenum, jejunum, ileum, colon, and rectum of each dog. Bacterial DNA was extracted from the samples, and the variable V6 to V8 region of 16S ribosomal DNA (gene coding for 16S ribosomal RNA) was amplified by use of universal bacterial primers; polymerase chain reaction amplicons were separated via denaturing gradient gel electrophoresis (DGGE). Similarity indices of DGGE banding patterns were used to assess variation in the bacterial microflora among different compartments of the intestine within and among dogs. Bacterial diversity was assessed by calculating the Simpson diversity index, the Shannon-Weaver diversity index, and evenness.

Results—DGGE profiles indicated marked differences in bacterial composition of intestinal compartments among dogs (range of similarity, 25.6% to 36.6%) and considerable variation among compartments within individual dogs (range of similarity, 36.7% to 57.9%). Similarities between neighboring intestinal compartments were significantly greater than those between non-neighboring compartments. Diversity indices for the colon and rectum were significantly higher than those of the duodenum, jejunum, and ileum.

Conclusions and Clinical Relevance—Results indicated that the different intestinal compartments of individual dogs appear to host different bacterial populations, and these compartmental populations vary among dogs. In dogs, fecal sample analysis may not yield accurate information regarding the composition of bacterial populations in compartments of the gastrointestinal tract. (Am J Vet Res 2005;66:1556–1562)