Glanzmann Thrombasthenia Great Pyrenees type (GT) is a form of thrombasthenia, a bleeding disorder caused by a disfunction in blood clotting. GT can be divided into three groups, type I, type II and variant GT. Type I is characterized by severe quantitative deficiency, type II by moderate quantitative deficiency and variant by relatively normal quantity but reduced function.The disorder in dogs is characterized by prolonged bleeding time and formation of hematomas at sites of injury. Other manifestation of the disease includes purpura, epistaxis, gingival hemorrhae, petechial hemorrhages on buccal mucosa and sporadically on the abdomen. Epistaxis and melena are common among affected dogs. Age of initial onset, from birth. Affected dog appears to be smaller than breed average. The dog will have also prolonged clotting times post-operatively.