title: Hemostatic analysis of dogs naturally envenomed by the African puffadder (Bitis arietans) and snouted cobra (Naja annulifera).
abstract: OBJECTIVE
  To investigate hemostatic changes in dogs envenomed by cytotoxic (African puffadder) and neurotoxic snakes (snouted cobra) using thromboelastography (TEG) and plasma-based coagulation assays.
  
  
  METHODS
  Prospective observational clinical study.
  
  
  METHODS
  University teaching hospital.
  
  
  METHODS
  Eighteen client-owned dogs; 9 envenomed by African puffadder (Bitis arietans) and 9 by snouted cobra (Naja annulifera). Ten healthy dogs served as controls.
  
  
  METHODS
  None.
  
  
  RESULTS
  Blood was collected at presentation and 24 hours post envenomation. Platelet count, TEG, prothrombin time, activated partial thromboplastin time (aPTT), antithrombin activity, and fibrinogen (Fib) and C-reactive protein (CRP) concentrations were measured. Outcomes were analyzed using linear mixed models at 5% significance. At presentation, R time was significantly prolonged in the puffadder group compared to the cobra (P = 0.01) and control groups (P = 0.05). Platelet count was significantly lower in the puffadder compared to the cobra (P = 0.04) and control groups (P = 0.001), respectively. Antithrombin activity was significantly decreased in the puffadder (P = 0.002) and cobra groups (P = 0.004) compared to the control group. Both prothrombin time and activated partial thromboplastin time were significantly prolonged in the cobra group compared to the control group (P = 0.03 for both). The TEG variables, maximum amplitude (MA) and G, were significantly increased 24 hours post envenomation in the puffadder group compared to their values at presentation (P = 0.05 for both). Fib and CRP concentrations were significantly increased 24 hours post envenomation in both snake-envenomed groups.
  
  
  CONCLUSIONS
  Prolonged clot initiation was a common feature in puffadder-envenomed dogs at presentation and this was likely venom induced. Snouted cobra-envenomed dogs were normo- to hypercoagulable at presentation. Dogs from both puffadder and cobra groups progressed to a more hypercoagulable by 24 hours post envenomation, most likely due to marked inflammation as indicated by the increased Fib and CRP concentrations. TEG proved a sensitive tool for detecting abnormal hemostasis in snake-envenomed dogs.
authors.affiliation: From the Departments of Companion Animal Clinical Studies (Nagel, Schoeman, Goddard).
authors.forename: Susanna S
authors.initials: SS
authors.lastname: Nagel
authors.forename: Johan P
authors.initials: JP
authors.lastname: Schoeman
authors.forename: Peter N
authors.initials: PN
authors.lastname: Thompson
authors.forename: Bo
authors.initials: B
authors.lastname: Wiinberg
authors.forename: Amelia
authors.initials: A
authors.lastname: Goddard
mesh_terms: D000818:Animals; D002097:C-Reactive Protein / Q000378:metabolism; D004283:Dog Diseases / Q000097:blood*; D004285:Dogs; D017815:Elapidae; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D008137:Longitudinal Studies; D008297:Male; D010314:Partial Thromboplastin Time / Q000662:veterinary; D010976:Platelet Count / Q000662:veterinary; D011446:Prospective Studies; D011517:Prothrombin Time / Q000662:veterinary; D012909:Snake Bites / Q000097:blood / Q000662:veterinary*; D013916:Thrombelastography / Q000662:veterinary; D017819:Viperidae
chemical_list: D005340:Fibrinogen; D002097:C-Reactive Protein
keywords: coagulopathy; snake; thrombocytopenia; thromboelastography; venom