Association of admission plasma D-Dimer concentration with diagnosis and outcome in horses with colic

Background: Coagulopathies detected in horses with gastrointestinal problems seem to be associated with poor outcome. Plasma D-Dimer concentration is a sensitive test for assessing coagulopathies. Hypothesis: Plasma D-Dimer concentration tested on admission is related to diagnosis and outcome in horses with colic. Animals: Four hundred and ninety three horses referred for evaluation of abdominal pain. Methods: Prospective observational clinical study. Horses were grouped according to diagnosis (medical and surgical intestinal obstructions, ischemic disorders with and without intestinal resection, enteritis, peritonitis), outcome (survivors, nonsurvivors), and number of coagulopathies (normal profile, 1 or 2 coagulopathies, subclinical disseminated intravascular coagulation [DIC]). Blood samples were collected on admission and plasma D-Dimer concentration, clotting times (PT and aPTT), and antithrombin activity were determined. Positive likelihood ratios (LR1) were calculated for evaluation of D-Dimer cut-off values, which were later tested in a logistic regression model. Results: Horses with enteritis or peritonitis had significantly (P o .001) higher plasma D-Dimer concentrations and more severe coagulopathies on admission than horses with other diagnoses. Nonsurvivors also had significantly (P o .001) higher plasma D-Dimer concentrations at presentation than did survivors, and those horses with subclinical DIC on presentation had an odds ratio (OR) 8.6 (95% confidence interval [CI], 3.3-22.5, P o .001) for nonsurvival. Finally, D-Dimer concentrations 44,000 ng/mL had a LR1 of 5.9 and an OR 8.8 (95% CI, 4.5-17.1, Po .001) for nonsurvival. Conclusion and Clinical Importance: Plasma D-Dimer concentration measured on admission can be used to facilitate diagnosis and outcome prediction in horses with colic. A potential cut-off value for nonsurvival was found at approximately 4,000 ng/m

Low-molecular-weight heparin dosage in newborn foals

Background: Heparin is used in humans as prophylaxis of hypercoagulable states and disseminated intravascular coagulation (DIC). However, babies need a higher heparin dose than do adults. Septic neonate foals are at high risk of hypercoagulable state and DIC, and there is limited objective information about heparin dose for equine neonates. Objective: To assess whether neonate foals require higher dosages of low-molecular-weight heparin (LMWH) than adults. Animals: Eighteen healthy and 11 septic neonate foals. Methods: Experimental and clinical studies. Firstly, healthy foals were randomly distributed in 2 groups, 1 receiving 50 IU/ kg SC of dalteparin and the 2nd group receiving 100 IU/kg SC of dalteparin, once daily for 3 days. Blood samples were collected before and 3, 6, 27, and 51 hours after the 1st LMWH administration. Plasma antifactor-Xa activity was measured, together with hemostatic and hematologic parameters used to assess the risk of bleeding. Subsequently, septic foals were treated blindly either with placebo (saline) or 100 IU/kg of dalteparin for 3 days. Plasma antifactor-Xa activity and other hemostatic parameters were determined before and after treatment. Results: Plasma antifactor-Xa activity in healthy foals was below prophylactic activity when using the adult dosage (50 IU/ kg), whereas prophylactic activities were achieved when using the double dosage (100 IU/kg). No hemorrhagic events and erythrocyte-related complications were observed with either dosage. In the clinical study, only 4/6 septic foals had plasma antifactor-Xa activity adequate for prophylaxis. Conclusions and Clinical Importance: Equine neonates require higher dosages of LMWH compared with adults to reach prophylactic heparinemia