Heart water is a tick borne infectious disease of ruminants affecting cattle, sheep, goats and antelope which is caused by the rickettsia organism cowdria ruminatium. The objective of this seminar is to review on heart water disease (cowdrosis) with the successful control of the disease. Heart water occurs only where vector ticks of the genus amblyomma are active and was limited in its occurrence to Africa, Madagascar and three countries in the West Indies. It is one of the main causes of death in imported breeds of cattle, sheep and goats in Africa south of the Sahara desert. A tentative diagnosis of heart water is based on the presence of amblomma vectors, of clinical nervous signs, and of transudates in the pericardium and thorax at postmortem examination, which must then be confirmed by demonstration of the causative organism or its DNA. Methods of control and prevention of cawdriosis is through chemotherapy, vaccination and vector control. Therefore calves of less than 4 weeks and lambs in the first week of life should be immunized.