title: Viscoelastic pharmacodynamics after dalteparin administration to healthy dogs.
abstract: OBJECTIVE
  To evaluate the pharmacodynamic effects of dalteparin in dogs by means of viscoelastic coagulation monitoring with a thromboelastograph and a dynamic viscoelastic coagulometer.
  
  
  METHODS
  6 healthy adult mixed-breed dogs.
  
  
  METHODS
  Dalteparin (175 U/kg, SC, q 12 h) was administered for 4 days (days 1 through 4). Viscoelastic coagulation monitoring was performed hourly on the first and last days of treatment and included intermittent measurement of anti-activated coagulation factor X activity (AXA).
  
  
  RESULTS
  Dalteparin administration resulted in progressive hypocoagulability. On both day 1 and 4, activated clotting time and clot rate for the dynamic viscoelastic coagulometer differed significantly from baseline values, whereas the platelet function parameter did not change on day 1 but did on day 4. The R (reaction time), time from reaction time until the amplitude of the thromboelastography tracing is 20 mm, α-angle, and maximum amplitude differed from baseline values on days 1 and 4, although many thromboelastographic variables were not determined. The AXA was increased from baseline values at 3 and 6 hours after administration of the dalteparin injection on days 1 and 4, and all dogs had AXA values between 0.5 and 1.0 U/mL at 2 and 4 hours after administration. The AXA correlated well with activated clotting time (r = 0.761) and with R (r = 0.810), when values were available. Thromboelastography could not be used to distinguish AXA > 0.7 U/mL.
  
  
  CONCLUSIONS
  Viscoelastic coagulation monitoring with strong coagulation activators may be used to monitor treatment with dalteparin in healthy dogs.
authors.affiliation: Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA. brainard@uga.edu
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Brainard
authors.forename: Amie
authors.initials: A
authors.lastname: Koenig
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Babski
authors.forename: April E
authors.initials: AE
authors.lastname: Blong
authors.forename: Jordan R
authors.initials: JR
authors.lastname: Scherk
mesh_terms: D000818:Animals; D000925:Anticoagulants / Q000008:administration & dosage / Q000494:pharmacology*; D001777:Blood Coagulation / Q000187:drug effects*; D001780:Blood Coagulation Tests / Q000379:methods* / Q000662:veterinary; D017985:Dalteparin / Q000008:administration & dosage / Q000494:pharmacology*; D004285:Dogs / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005170:Factor X / Q000378:metabolism*; D005260:Female; D007267:Injections / Q000662:veterinary; D008297:Male; D013916:Thrombelastography / Q000379:methods / Q000662:veterinary
chemical_list: D000925:Anticoagulants; D005170:Factor X; D017985:Dalteparin