Epidemiology of malignant form of foot-and-mouth disease in susceptible cattle and buffalo population of Punjab and Uttar Pradesh

The unusual heavy mortality in cattle and buffp1ges involving 140 villages in 4 blocks of Moga district, 25 villages under Zira subdivision (Firozpur), several others in Ludhiana and Faridkot of Punjab, and more than 17 villages in Bagpat (7 villages), Meerut (8 villages), Muzzafarnagar (1 village) and Ghaziabad (1 village) of Uttar Pradesh were investigated during February and March 1998. Altogether 3,663 cattle and buffaloes died and more than 6,000 others got affected in Moga (Dattiwala village), Firozpur (Rainwala village), Faridkot, and Ludhiana (Shah Bucker and Mohie villages) districts. In UP, 10412150 cattle and buffaloes had died in Basuli (Baghpat), 6012500 in Bhamori (Meerut) and 60/6000 in Kharad (Muzaffemagar) villages. The affected animals showed high fever (104-105°F), anorexia, dullness, dehydration, stomatitis, frothy/ropy salivation and lameness. The buccal mucosa, tongue, rumen and the skin of hooves were hyperemic and had intact/ruptured or healed vesicles. Few animals also showed vesicles on their teat orifices. In majority of the cases, necrotizing non-suppurative myocarditis (tigroid heart) was recorded in association with presence of serosanguinous fluid in the intestinal lumen. Sudden death, severe congestion of intestines and lungs were confused with pasteurellosis. The immunocapture ELISA assays in tissues from both the states detected FMD type O virus. However, no other pathogenic bacteria/virus could be isolated on culture examination. The affected pigs, that migrated through Dattiwala village (Punjab), were the suspects for FMD virus spread, while a Murrah buffalo translocated from affected area of Punjab was the source of FMD outbreaks in Basuli (Baghpat, Uttar Pradesh). The reasons for wide spread transmission and high mortality (mostly in suckling/weaned, younger and highly productive animals) in cattle and buffaloes at both the places were attributed to conducive cold-fogy weather, rapid trading and mobility of animals, presence of large number of susceptible livestock (pure/crossbred) and involvement of FMD type '0' virus.