Thromboelastographic Evaluation of Dogs with Congenital Portosystemic Shunts

Abstract

Background: On plasma-based assays, dogs with congenital portosystemic shunts (CPSS) have changes in serum concentrations of both pro-and anticoagulant proteins, but how these abnormalities affect whole blood coagulation assays (eg, thromboelastography) are unknown.Objectives: To conduct kaolin-activated thromboelastography (TEG) analysis in dogs with CPSS and to compare TEG coagulation status with clinical presentation, routine serum biochemistry, and plasma-based coagulation tests.Animals: Twenty-one client-owned dogs with CPSS confirmed by ultrasound examination or nuclear scintigraphy. Methods: In a prospective study, signalment, clinical presentation, TEG analysis, CBC, serum biochemistry, and hemostatic tests (platelet count, prothrombin time [PT], activated partial thromboplastin time [aPTT], quantitative fibrinogen, antithrombin [AT] activity, protein C [PC] activity, d-dimers, and factor VIII activity) were analyzed in dogs with CPSS.Results: Dogs with CPSS had significantly shorter K values and increased angle, maximum amplitude (MA), and G values compared with the reference population. On plasma-based coagulation testing, dogs with CPSS had significantly prolonged PT, lower platelet counts, lower AT and PC activities, and increased d-dimers and factor VIII activity. Evaluation of G value defined 9/21 dogs with CPSS as hypercoagulable. These dogs were more likely to have hepatic encephalopathy (HE) than CPSS dogs that had normal coagulation.Conclusions and Clinical Importance: TEG analysis detected hemostatic abnormalities consistent with a hypercoagulable state in some dogs with CPSS. The presence of a hypercoagulable state was 40 times more likely in dogs with symptomatic HE.

Thromboelastographic Evaluation of Dogs with Acute Liver Disease

“…After a 30‐minute hold period at room temperature, a single operator performed kaolin‐activated TEG. Reference ranges for TEG variables were established in the Coagulation Laboratory in the Foster Hospital at the Cummings School . The remaining citrated plasma was stored at −80°C for analysis of PT, , aPTT, , quantitative fibrinogen, , AT activity, , PC activity, , d‐dimers, , and vWF activity , .…”

“…Similar to humans with cholestasis, dogs with extrahepatic bile duct obstruction most often are hypercoagulable . In addition, dogs with portosystemic shunts appear to be mildly hypercoagulable . No studies to date have reported TEG findings in dogs with ALD.…”

“…13 In addition, dogs with portosystemic shunts appear to be mildly hypercoagulable. 14 No studies to date have reported TEG findings in dogs with ALD.…”

ACVIM consensus statement on the diagnosis and treatment of chronic hepatitis in dogs

“…At this time, the value of TEG in predicting coagulation status in dogs with CH is unknown. Plasma fibrinogen concentrations seemingly reflect TEG indices of clot strength in dogs with liver disease . As such, plasma fibrinogen concentration is recommended for bleeding risk assessment in CH …”

Haematology and coagulation profiles in cats with congenital portosystemic shunts

“…Most studies assessing coagulation in dogs with a CPSS or other hepatic disease have investigated for the presence of hypocoagulability, [1][2][3][4] and one study has identified hypercoagulability in some dogs with a CPSS. 5 Previous studies of dogs with CPSS have shown that 35-84% had microcytosis and 16-70% were anaemic, whilst 7-53% had a prolonged prothrombin time, and 5-64% had a prolonged activated partial thromboplastin time (aPTT). 1,[3][4][5][6][7][8][9][10] A leukocytosis is variably present with documented prevalence of between 15.4-40%.…”