Prognostic Value of Cardiac Troponin I and L‐Lactate in Blood of Dairy Cows Affected by Downer Cow Syndrome

Abstract

BackgroundThe downer cow syndrome (DCS) is a challenging health issue in the dairy industry. No cow‐side test is available to provide an accurate prognosis for DCS cases in farm settings.Hypothesis/ObjectivesLocal or systemic hypoperfusion and myocardial lesions lead to an increase in blood concentration of biomarkers cardiac troponin I (cTnI) and L‐lactate. The objective was to determine the prognostic values of these biomarkers assessed cow‐sides in addition to clinical examinations in prognostication of a negative outcome (NO: death or euthanasia within 7 days).Animals218 client‐owned dairy cows affected by DCS.MethodsIn a prospective study, animals were monitored for 60 days after inclusion of each cow. Blood cTnI and L‐lactate concentrations were measured on the day of inclusion. The prognostic accuracy of both biomarkers and physical examination variables was estimated to predict NO. A mixed multivariable logistic regression model was used for data analysis.ResultsPrevalence of NO in this study was 63% on day 7. Troponin concentrations greater than 0.7 ng/mL had sensitivity and specificity of 54.1% (95% CI: 45.3–62.7%) and 78.4% (95% CI: 67.3–87.1%), respectively, for predicting NO. Blood L‐lactate was not associated with the outcome. The multivariable model revealed that heart rate >100 bpm (OR; 95% CI: 3.7; 1.3–10.2) and cTnI > 0.7 ng/mL (OR; 95% CI: 5.5; 2.1–14.6) were associated with the risk of NO.Conclusions and Clinical ImportanceHypertroponinemia and tachycardia were associated with reduced survival in DCS cases. The use of cow‐side blood cTnI concentrations and heart rate could help to rapidly identify cows in farm setting that have poor chances of recovery and would benefit from a more aggressive treatment or euthanasia.

Electrocardiogram and serum cardiac biomarkers changes in FMD in cattle

“…Variations are expected in measuring cTnI concentrations when samples are evaluated with different immunoassays (14). The cTnI level has recently been used for determination of myocardial cell damage in different pathologic conditions such as FMD in lambs (15), traumatic reticuloperitonitis (16), endotoxemia (17), monensin toxicosis (12), theileriosis (7), bovine respiratory disease (18) in calves and cattle, and downer cow syndrome (19). In our study, the serum cTnI concentration of healthy control cow was 0.14 ± 0.04 ng/mL, which is close to and consistent with the findings of Başbuğan et al (13), but does not agree with findings from other studies (1,12,14).…”

Survival and prognostic indicators in downer dairy cows presented to a referring hospital: A retrospective study (1318 cases)

“…In previous studies, survival percentage varied from 11% to 50% when downer cows were treated at the farm 2,7‐10 . For downer cows treated at a referring hospital, survival percentage was reported to be 37% 6 .…”

Comparison of Two Commercially Available Immunoassays for the Measurement of Bovine Cardiac Troponin I in Cattle With Induced Myocardial Injury

“…Similarly, a 15 day old calf that died of severe myocarditis had a circulating antemortem cTnI concentration of 37.24 ng/mL (55). Downer dairy cows with a cTnI concentration of >0.7 ng/mL have worse prognosis within 7 days of testing (27). Therefore, while analytical discrepancies may be largely ignored in some populations of cows, in particular when cTnI concentrations are low or below the lower limit of detection of the assay, they may become more important in animals with elevated cTnI where estimation of the severity of myocardial damage is clinically relevant.…”

“…Multiple toxicities have been reported to increase cTnI in ruminant species, ranging from plants such as Rayless Goldenrod ( Isocoma pluriflora ), ( 21 ) to anti-inflammatories such as diclofenac ( 22 ), as well as the ionophore antibiotics, such as monensin ( 23 – 25 ). As such, any increased blood concentration of cTnI is an indicator of myocardial injury and has been associated with an adverse clinical outcome in human patients ( 26 ), as well as downer cattle ( 27 ). There are currently multiple clinical applications for cTnI in bovine practice.…”