Porcine Ascaris suum Infection Study Guide

Overview and Clinical Importance

Ascaris suum (the large roundworm of pigs) is the most common and economically important internal parasite of swine worldwide. This soil-transmitted helminth causes significant economic losses through liver condemnation at slaughter (milk spots), reduced feed efficiency, and decreased growth rates. Understanding A. suum is critical for the NAVLE as it appears frequently in questions about swine parasitology, zoonotic potential, and herd health management.

The parasite undergoes a complex hepato-tracheal migration that causes characteristic pathological lesions. A. suum is closely related to the human roundworm (Ascaris lumbricoides), and cross-species infection is documented, making this parasite a One Health concern.

Etiology and Classification

Taxonomic Classification

Morphology

Adult Worms

A. suum adults are among the largest nematodes parasitizing domestic animals. They are characterized by their pinkish-white color when freshly passed and possess three prominent lips surrounding the mouth, each containing a dentigerous ridge.