Validierung anamnestischer Angaben und ausgewählter klinischer Befunde im Hinblick auf Endokarditis beim Rind

Association of results of the glutaraldehyde coagulation test with plasma acute phase protein concentrations and hematologic findings in hospitalized cows

Introduction

The glutaraldehyde test (GAT) allows for animal-side semi-quantitative estimation of fibrinogen and gamma-globulin concentrations in blood samples of adult cattle and therefore detection of inflammatory disease conditions. However, the test has potential limitations, especially due to the latency period until sufficiently high fibrinogen and/or gamma-globulin concentrations are reached. The aim of the present study was therefore to assess the association between results of GAT with other inflammatory markers including hematologic variables, fibrinogen, plasma haptoglobin and serum amyloid A (SAA) concentrations.

Methods

For the purpose of this prospective observational study, a convenience sample of 202 cows with a broad range of inflammatory and non-inflammatory clinical conditions was included. The GAT was run on EDTA blood, fibrinogen was measured using the Clauss and the heat precipitation method, and commercially available ELISA tests were used for determination of plasma haptoglobin and SAA concentrations.

Results

Shortened GAT coagulation times were more closely correlated to serum globulin (rs  = -0.72) than to plasma fibrinogen concentrations measured with the heat precipitation (rs  = -0.64) and the Clauss method (rs  = -0.70). Cows with a markedly (≤3 min) or moderately (4-6 min) shortened coagulation time had higher (p < 0.001) plasma haptoglobin and SAA concentrations than cows with a negative test result. Total leukocyte, monocyte and neutrophil concentrations did not differ significantly between groups. An identified cut-off for the GAT coagulation time of ≤14 min had a sensitivity and specificity of 54.4 and 100%, respectively, for the prediction of an inflammatory state based on clinical findings and/or increased plasma haptoglobin or SAA concentrations.

Discussion

In conclusion, this study demonstrates considerable diagnostic agreement between positive GAT results and increased plasma concentrations of haptoglobin and SAA. Despite high specificity, the test lacks sensitivity in case of acute inflammatory conditions indicating that plasma acute phase protein concentrations and hematologic findings can provide additional diagnostic information if the GAT is negative.

The diagnostic criteria used in bovine bacterial endocarditis: a meta-analysis of 460 published cases from 1973 to 2011

Bacterial endocarditis (BE) is the most common valvular disease in cattle but diagnosis in the living animal remains a challenge for clinicians. The objective of the study was to report evidence-based veterinary medicine data concerning the clinical presentation and results of ancillary tests of necropsy-confirmed cases of bovine BE. A systematic review and subsequent meta-analysis was performed using Medline and CAB abstracts of every article on bovine BE published in English, Japanese, German and French. The clinical criteria that were specifically assessed for diagnosis of BE were: tachycardia, heart murmur, signs of congestive heart failure, presence of fever, evidence of lameness/polyarthritis, one or more positive blood cultures and positive echocardiograms for BE. A total of 34 studies (460 cases of BE) satisfied the inclusion criteria for the systematic review. The sensitivity (Se), specificity (Sp) and 95% confidence interval (CI) were obtained using a random-effect meta-analysis for studies reporting five or more cases. The Se (95% CI) were 86.9% (39.1-98.6%) for positive haemoculture, 84.3% (60.4-95.0%) for echocardiography, 79.7% (70.1-86.8%) for the presence of tachycardia, 60.3% (51.8-68.3%) for the presence of a murmur, 45.7% (32.5-59.5%) for the presence of fever, 43.5% (25.6-63.3%) for the presence of lameness/polyarthritis, and 37.3% (21.6-57.0%) for the presence of clinical signs of heart failure. The Sp (95% CI) was 95.3% (93.3-96.8%) for lameness, 72.6% (45.8-89.2%) for the presence of a murmur, 67.0% (55.5-76.7%) for the presence of fever, and 27.1% (14.3-45.2%) for the presence of tachycardia. This meta-analysis confirmed that the diagnosis of BE is a difficult process. Echocardiography seems to be a sensitive diagnostic tool despite the absence of any consensus on the ultrasonographic definition of the disease. However, from these results, it was impossible to determine whether multiple positive findings or clinical tests increase the sensitivity for the diagnosis of bovine BE.