The disease is characterised by vesicles on the legs and around the mouth of affected pigs, hence the possible confusion with foot and mouth disease.
The pigs may be lame while the vesicles appear and subsequently rupture. Less commonly, they may also be feverish and reluctant to eat. The clinical signs vary with the strain of the virus (there is one serotype containing several distinct strains): the disease can be severe, mild or subclincal (shows no clinical signs but is infected and will still be infectious to others).
Younger animals tend to show more severe clinical signs than older pigs, and animals housed on wet concrete are usually worse affected than those on straw or grass (abrasion from hard floors bursts the vesicles and promotes secondary infection).
Severe disease is unusual, outbreaks more often feature disease with mild clinical signs. Generally, the illness is short-lived and most pigs make a full recovery in 2-3 weeks. It is unusual for pigs to die of swine vesicular disease.