Clinical signs associated with parascaris equorum infection in worm-free pony foals and yearlings

The clinical signs associated with a single infection of 8 000 Parascasis equorum eggs in eight worm-free foals and two yearling ponies are described. Foals had mild respiratory disease 2–4 weeks after infection whilst the yearlings showed a more severe respiratory syndrome with systemic illness. The foals became progressively lethargic and emaciated from the third month onwards, but they yearlings maintained good condition.Infections became patent on days 101–104 post inoculation.