First indication of the disease in cattle is fever accompanied by depression and a severe milk production drop. This can occur as short as 2-3 days after infection. Vesicles can develop within a day after the first signs are observed. These are first observed on the tongue, lips, gum and dental pad. They then appear in the interdigital cleft, coronary bands and heel bulbs and manifest as lameness.
Vesicles also appear on the teats.
The vesicles rapidly enlarge and generally rupture in 24 hours. In pigs, the lesions tend to be more pronounced on the feet, resulting in acute lameness. Vesicles are found on the snout, but vesicles on the tongue are not common, tend to be small and quickly heal. The pig is important in the spread of the infection. Numerous outbreaks have been attributed to the initial feeding of contaminated or infected material to pigs.