VPA 211: General Veterinary Parasitology and Helminthology (3+1)

PATHOGENESIS

• The worms attach themselves firmly to the mucosa of the colon by means of their buccal capsule and draw in a plug of mucosa of the glandular layer and digest the layer by their secretions.
• The adjoining parts of the mucosa show an increased activity of goblet cells and infiltration with lymphocytes and eosinophils.
• The worms appear to move about frequently causing extensive destruction of the mucosa and thereby leading to bacterial infiltration.
• They also have a toxic action.
• In severe infections sheep lose condition and become anemic and die.