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.
Autoimmune diseases, most notably thyroiditis, are being reported in dogs with increasing frequency. The increase is in part due to better veterinary knowledge of this type of disease and improved diagnostic techniques. Environmental conditions (toxic exposure, diet, stress, etc.) can induce autoimmune disease. A dog's genetic make-up plays a role. It is vital that breeders inform themselves about the treatment and inheritance factors of autoimmune disease. Autoimmune disease does not just happen; it requires a trigger, an event that starts the disease process.