Từ điển thú y vần M | M M B 693 The code name given by the manufacturer May Baker now part of Merial to sulphapyri-dine one of the SULFONAMIDE DRUGS. It was the first sulfonamide to be introduced into the UK in 1938. Macaw-Worm Fly This is a parasite of cattle and other animals in Central America. It is another name for the warble-fly Dermarobia homini. See under FLIES. Macrocyte Macrocyte is the term applied to an abnormally large erythrocyte especially characteristic of the blood in some forms of anaemia. Macrophage A former monocyte type of white blood cell which has migrated into the tissues and become larger. See under BLOOD INFECTION. Macules Macules are spots or stained areas of skin or mucous membrane usually brownish red or purple in colour. Mad Cow Disease see BOVINE SPONGIFORM ENCEPHALOPATHY Madness in Dogs see RABIES ENCEPHALITIS MENINGITIS Maedi Visna A slowly progressive disease of sheep and goats first recognised in 1939 in Iceland and believed to have been introduced into that country by karakul sheep imported from Germany. Iceland is now free from the disease following 2 eradication programmes but maedi occurs in the UK continental Europe North America Africa and Asia. Although maedi visna has never been recorded in Australia a retrovirus was isolated from goats there and shown to produce antibodies indistinguishable from those produced by maedi visna virus in goats. Cause A lentivirus. It is usually seen in animals over 2 years old. Transmission to the lamb is often via the ewe s milk. Maedi is the Icelandic word for dyspnoea and the disease is a type of pneumonia with a very long incubation period 1 to 3 years or even more. An early sign is dyspnoea after physical exertion the breathing becomes very rapid and shallow. Later breathing becomes difficult even when the animal is at rest and death often follows. Visna is a name applied to the same viral infection when the brain or spinal cord rather than the lungs are involved. Demyelination occurs. Diagnosis can be .
