Mary K. Boudreaux, DVM, PhD, Professor, Department of Pathobiology
Hemostasis: Lecture Notes
About the Author:
Dr. Boudreaux has been teaching veterinary students about hemostasis for over 25 years. In an effort to provide veterinary students with concise, up-to-date, easy to understand information on hemostasis in domestic animals she developed her own hemostasis handout for Auburn veterinary students in 1986. Her research efforts in this area combined with the efforts of others has allowed continual updating of information each year. This document represents over 25 years of commitment to the teaching of hemostasis to veterinary students with an emphasis on normal hemostasis, acquired and inherited disorders of hemostasis, and methods of identification of hemostatic disorders in domestic animals.
About the Booklet:
The aim of the booklet is to educate veterinary students in a Clinical Pathology course setting about the various aspects of hemostasis in an easy to understand and concise format. A summary of the components of normal hemostasis is provided followed by sections on platelets, coagulation, and fibrinolysis. The platelet and coagulation sections provide brief descriptions of acquired and inherited disorders that have been described in animals along with appropriate methods of sample collection, available diagnostic assays, and interpretation of test results. Diagnostic assays presented include biochemical as well as molecular methods when available. Tables near the end of the document assist with summarizing the information in a concise format. A study guide is provided to help students focus on learning specific aspects of hemostasis. Sample cases are also provided to assist the students with applying the information learned in a case-based, clinical-type format. References are included for students who wish to obtain more information on a particular topic.
Evaluating the role of platelets in disease pathogenesis and identification and characterization of congenital platelet disorders.
My research interests include evaluating the role of platelets in disease pathogenesis and identification and characterization of congenital platelet disorders. Our platelet laboratory can isolate mammalian platelets from a variety of species for evaluation of platelet reactivity. We have developed a monoclonal antibody (CAP1) that detects a receptor-induced binding site (RIBS) on canine fibrinogen. The antibody has been useful in detection of platelet activation in dogs using flow cytometry and has also been useful in the characterization of congenital platelet disorders.
Recently we have begun using flow cytometry and CAP1 to identify and characterize platelet disorders in animals that cannot be taken to
As part of our interest in congenital platelet disorders we determined the normal gene sequences encoding platelet glycoproteins IIb and IIIa in dogs and horses. This work led to the discovery of the genetic basis for Glanzmann thrombasthenia (GT) in Great Pyrenees dogs and Otterhounds as well as the identification of 2 separate mutations causing GT in horses.
During the late summer and fall of 2006 distinct mutations in the gene encoding calcium diacylglycerol guanine nucleotide exchange factor I (CalDAG-GEFI) were identified as causing thrombopathia in Basset hounds, Eskimo Spitz, Landseers of European Continental Type (ECT), and Simmental cattle.
During the summer of 2007 a mutation in the gene encoding beta1-tubulin was found to correlate with the macrothrombocytopenia described in Cavalier King Charles Spaniels. Since that time the identical mutation has been identified in several other breeds including Chihuahua, Labrador retriever, Poodle, English Toy Spaniel, Shih Tzu, Labradoodle, Maltese, Jack Russell, and Havanese.
Recently a distinct mutation in the gene encoding beta1-tubulin has been identified in Norfolk and Cairn Terriers. In 2009 a mutation in the gene encoding Kindlin-3, a signal transduction protein important in integrin activation in platelets and leukocytes, was identified in a German Shepherd dog. The affected dog experienced life-long bleeding, high white cell counts, and susceptibility to infections. This syndrome is referred to as LAD-I Variant or LAD-III. Also in 2009 a mutation was identified in a gene encoding a platelet activating receptor in a Greater Swiss Mountain Dog. This dog experienced prolonged bleeding following a routine spay.
Information on testing for GT in Great Pyrenees or Otterhounds, for CalDAG-GEFI thrombopathias in Basset hounds, Eskimo Spitz, or Landseers-ECT, for congenital macrothrombocytopenia in Cavalier King Charles Spaniels and other breeds, for LAD-I Variant in German Shepherd dogs, and for a platelet disorder in Greater Swiss Mountain Dogs can be found below: