Systematic Veterinary Virology

ACUTE FORM

• Peracute infection
  • Observed in piglets, where young pigs may be found dead without any prior sign of illness.
• Acute infection
• In acute form the pigs appear sick, inactive and drowsy with arched back. Some pigs stand with droopy head and straight tail.
• They may huddle to a corner for warmth. Some pigs also vomit a yellow fluid containing bile.
• The most important symptom in acute infection is the high fever that may reach 108°F (42.2°C) with an average of 106°F (41.1°C) accompanied by anorexia and constipation.
• Conjunctivitis with encrustation of the eyelids and the presence of dirty streaks below the eyes is the other important symptom. Sick pigs will have a staggering gait and posterior weakness.
• In last stage of the infection, pigs will become recumbent, and convulsions may occur shortly before death. Sever diarrhoea will also occur during last stages.
• There may be purple discoloration of abdominal skin, or necrosis of the tips of extremities (ears, tail, vulva). Neurological signs may occur, which include incoordination, tremors, convulsions and circling. Death usually occurs 5-15 days after the onset of illness.