Anaplasmosis: A Disease of Cattle

ANAPLASMOSIS was probably introduced into the United States by the Spaniards at the same time that splenic or cattle tick fever entered this country (IS),^ The disease, which is not transmissible to man, chiefly affects cattle, although the antelope, black wildebeest, blesbok, buffalo, camel, deer, duiker, elk, goat, and sheep are reported to be susceptible. Mature cattle are more subject to infection than young animals. Although calves doubtless acquire mild cases, they are seldom observed to be sick or dying in anaplasmosis-infected herds. Cattle of all breeds may acquire the disease. Some immunity appears to develop in herds in which anaplasmosis has long been prevalent, but a few authentic cases have been reported of a second attack after a year in cows that have recovered. Anaplasmosis is generally considered to be a tropical or semitropical disease, but it also occurs in localities that have low winter temperatures. It has been reported from Africa, Argentina, Brazil and several other South American countries, Cochin-China, France, Italy, Java, the Philippine Islands, the Union of Soviet Socialist Republics, and the Island of Taiwan. Ill the United States tlie malady is known to exist in 23 States— Alabama, Arizona, Arkansas, California, Colorado, Delaware, Flor-