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Updated: May 13, 2026
Ferric Chloride-induced Canine Carotid Artery Thrombosis: A Large Animal Model of Vascular Injury
Published on: September 7, 2018
Evaluation of coagulation in dogs with partial or complete extrahepatic biliary tract obstruction by means of
Philipp D Mayhew1, Michelle R Savigny, Cynthia M Otto
1Department of Clinical Studies-Philadelphia, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA. philmayhew@gmail.com
Objective:
To characterize in vitro coagulation status in a cohort of dogs with extrahepatic biliary tract obstruction (EHBO) and to evaluate these patients for hypercoagulability by means of thromboelastography.
Design:
Prospective cohort study. Animals-10 dogs with EHBO and 19 healthy control dogs.
Procedures:
Partial or complete EHBO was confirmed via exploratory celiotomy. Venous blood samples were collected for evaluation of prothrombin time (PT) and activated partial thromboplastin time (APTT); fibrinogen and D-dimer concentrations; protein C and antithrombin activities; and factor VII, VIII, and XI coagulant activities in plasma as well as thromboelastography in whole blood. Thromboelastography variables were measured from the thromboelastography tracing, and a coagulation index was calculated. Thromboelastography results were compared with those of healthy control dogs previously evaluated by the same laboratory.
Results:
Hypercoagulability was diagnosed in all dogs with EHBO on the basis of a high coagulation index. Thromboelastography variables, including maximal amplitude, α-angle, and coagulation index, were significantly higher, and K (clot formation time) and R (reaction time) were significantly lower in these dogs than in control dogs. All dogs with EHBO had PT and APTT within respective reference ranges. Plasma D-dimer and fibrinogen concentrations were above reference ranges in 8 and 7 dogs, respectively, and protein C and antithrombin activities were below reference ranges in 3 and 1 dogs, respectively.
Conclusions And Clinical Relevance:
In vitro hypercoagulability was commonly detected in dogs with naturally occurring EHBO. The traditional view of EHBO as a disease that causes hypocoagulability may need to be reconsidered.
