Definition of primary and secondary amenorrhea. Amenorrhea is the medical term for the absence of menstrual periods, either on a permanent or temporary basis. Amenorrhea can be classified as primary or secondary.
Most inherited bleeding disorders are the result of abnormal platelet function or a deficiency in one or more of the factors involved in the blood clotting system. The most serious and common inherited coagulation disorders in dogs are hemophilia(deficiency of factor VIII or IX) and von Willebrand's disease (lack of von Willebrand factor). Other coagulation disorders are discussed here.
This then reacts with factor III and so on to factor XII. In Von Willebrand's Disease, the dog is missing a substance, which helps the platelets form clots and stabilizes Factor VIII in the clotting process. This substance is called 'Von Willebrand's factor.' Because of the deficient clotting of blood, dogs with Von Willebrand's disease have excessive bleeding upon injury. This would be similar to hemophilia in humans. Certain breeds have a higher incidence of vWD than others.