Bleeding disorders in dogs 2. Acquired disorders

THIS article reviews the pathogenesis, clinical and laboratory diagnosis, and treatment of the major acquired haemostatic disorders that have been described in the dog. As with inherited haemostatic disorders (see Part 1, In Practice, January 2002, pp 2-10), the clinical expression of the bleeding associated with acquired disorders can sometimes be helpful in differentiating between primary (platelet or vascular) and secondary (coagulation) defects. However, unlike their inherited counterparts, acquired bleeding disorders usually result from multiple defects in the haemostatic response; since both primary and secondary defects may occur concurrently, the nature of the bleeding can vary considerably, and may show characteristics of both coagulation and platelet deficiencies. Appropriate haemostatic screening tests can provide valuable assistance in the detection and differentiation of these disorders.