A species of gram-negative bacteria in the family ANAPLASMATACEAE, that causes HEARTWATER DISEASE in ruminants.

A tick-borne septicemic disease of domestic and wild ruminants caused by EHRLICHIA RUMINANTIUM.

Small, often pleomorphic, coccoid to ellipsoidal organisms occurring intracytoplasmically in circulating LYMPHOCYTES. They are the etiologic agents of tick-borne diseases of humans; DOGS; CATTLE; SHEEP; GOATS; and HORSES.

A species of gram-negative bacteria that is the causative agent of human EHRLICHIOSIS. This organism was first discovered at Fort Chaffee, Arkansas, when blood samples from suspected human ehrlichiosis patients were studied.

Species of gram-negative bacteria in the family ANAPLASMATACEAE, causing EHRLICHIOSIS in DOGS. The most common vector is the brown dog tick. It can also cause disease in humans.

Curved bacteria, usually crescent-shaped rods, with ends often tapered, occurring singly, in pairs, or short chains. They are non-encapsulated, non-sporing, motile, and ferment glucose. Selenomonas are found mainly in the human buccal cavity, the rumen of herbivores, and the cecum of pigs and several rodents. (From Bergey's Manual of Determinative Bacteriology, 9th ed)

A tick-borne disease characterized by FEVER; HEADACHE; myalgias; ANOREXIA; and occasionally RASH. It is caused by several bacterial species and can produce disease in DOGS; CATTLE; SHEEP; GOATS; HORSES; and humans. The primary species causing human disease are EHRLICHIA CHAFFEENSIS; ANAPLASMA PHAGOCYTOPHILUM; and Ehrlichia ewingii.