ABSTRACT
CLINICAL PRESENTATION The incubation period is 2-10 days. Initially, one or two cattle present with pyrexia (>40.0°C), depression (604), anorexia, a marked drop in milk yield and salivation (605). Other cattle in the group at pasture may not yet show clinical signs, but the increase in disease morbidity within 24 hours in housed cattle is very dramatic. Vesicles on the tongue, dental pad and hard palate quickly rupture, leaving shallow ulceration with shreds of mucosa at the periphery (606, 607). The submucosa is markedly
hyperaemic. There are no ocular or nasal discharges. Vesicles may be present on the teats and at the coronary band (608, 609). They may become secondarily infected and cause lameness. Cattle under intensive management conditions with appropriate supervision would be detected at this stage, and in many countries compulsory slaughter of all cloven-hooved animals on the farm would ensue.
