PHARMACOKINETIC STUDY OF ORAL ε-AMINOCAPROIC ACID IN THE NORTHERN ELEPHANT SEAL (MIROUNGA ANGUSTIROSTRIS)

Viscoelastic Coagulation Testing in Exotic Animals

Whole blood viscoelastic coagulation testing (VCT) allows global assessment of hemostasis and fibrinolysis. Although not widely used in exotic animal practice, VCT has been used in exotic animal research settings. Differences in patient demographics and analytical variables can result in dramatically different results with the same analyzer. To improve the utility of VCT in exotic animal medicine, standardization of protocols is necessary to facilitate the establishment of reference intervals. Despite these challenges, the quantitative/qualitative nature of VCT has already proved its real-world value to some clinicians.

Diagnostic Performance of Clinicopathological Analytes in Otostrongylus circumlitis-Infected Rehabilitating Juvenile Northern Elephant Seals (Mirounga angustirostris)

The nematode lungworm, Otostrongylus circumlitis (OC), is a significant cause of northern elephant seal (NES; Mirounga angustirostris) mortality at The Marine Mammal Center (TMMC, Sausalito, CA). The current lack of specific antemortem diagnostic tests for pre-patent OC infection in NES makes diagnosis, proper treatment, and assessment of efficacy of medications challenging. Severe inflammation and disseminated intravascular coagulation (DIC) develop rapidly and are difficult to treat once clinical signs develop. Certain blood inflammatory and hemostasis biomarkers for early diagnosis have recently been investigated. The objective of this study was to investigate the diagnostic performance of complete blood count, serum chemistry, acute phase proteins, protein electrophoresis, and coagulation parameters for diagnosis of OC clinical infection in NES. Samples from NES with OC infection confirmed by gross pathology with blood collected antemortem during clinical disease (n = 9) and NES initially admitted for malnutrition and sampled shortly before release after successful rehabilitation (n = 20) were included in the study. Using Receiver operator characteristic (ROC) curve analysis, the diagnostic performances (area under the curve [AUC]) of albumin (0.994), albumin:globulin ratio (0.983), serum amyloid A (0.972), activated partial thromboplastin time (0.936), total bilirubin (0.975), and gamma-glutamyl transferase (0.939) were high (AUC > 0.9). These results confirm systemic inflammation and DIC, and support previously reported clinical and gross pathological findings in NES infected with OC. In addition to AUC values, this study produced cut-off points, sensitivity, specificity, confidence intervals, and predictive values for analytes with high diagnostic performance. This data will be useful in the diagnosis and clinical management of OC-infected NES and will aid in assessment of treatment efficacy.

Plasmatic coagulation and fibrinolysis in healthy and Otostrongylus-affected Northern elephant seals (Mirounga angustirostris)

BACKGROUND

Prepatent Otostrongylus arteritis results in hemorrhagic diathesis in free-ranging Northern elephant seals (Mirounga angustirostris) attributed to aberrant larval migration of the lungworm, Otostrongylus circumlitus. Clinical signs are often nonspecific, including lethargy, anorexia, and blepharospasm, but can progress to spontaneous frank hemorrhage and death within 72 hours of onset. Previously published case reports describe coagulopathy with prolonged PT and APTT, normal to elevated platelet counts, normal antithrombin concentrations, and low concentrations of fibrinogen degradation products. Disseminated intravascular coagulation was proposed as the cause of hemorrhage, but is inconsistent with some of the reported clinicopathologic changes.

OBJECTIVE

The purpose of this study was to compare plasmatic coagulation and fibrinolysis in healthy and Otostrongylus-affected elephant seals, in order to identify potential therapy. We hypothesized that hyperfibrinolysis contributed to hemorrhage in these cases.

METHODS

Citrated plasma samples were collected from 3- to 4-month-old Northern elephant seals in a wildlife rehabilitation hospital. The sampled population included 25 healthy, prerelease seals and 32 clinically ill seals diagnosed with presumptive Otostrongylus arteritis. Twenty-one of the included seals had Otostrongylus infestation confirmed at necropsy. Standard coagulation tests and plasma thromboelastography were performed for a complete assessment of coagulation and fibrinolysis.

RESULTS

Northern elephant seals with definitive Otostrongylus infestation were hypocoagulable and hypofibrinolytic compared to healthy controls.

CONCLUSIONS

Results were most consistent with disseminated intravascular coagulation. Treatment with antifibrinolytic drugs to control hemorrhage may be unrewarding; alternative therapies such as plasma transfusions or coagulation factor concentrates should be investigated.