Capillaria aerophila: Lungworm

General Description: Slender worms, males up to 24.5mm long, females as long as 32mm.

Life Cycle: Dogs and foxes are the hosts for Capillaria aerophila (present only in cats in New Zealand), which has a direct life cycle. Eggs are coughed up and swallowed and pass in faeces. Infective larvae develop in the eggs 5 to 7 weeks after leaving the host. Ingestion and digestion of eggs by dogs release larvae which penetrate the intestinal wall and migrate to the lungs, where they develop into adults. The prepatent period is about 40 days.

Location: Larger airways of the lungs.

Significance: Irritation of lungs may predispose animals to pneumonia.

Effect on Host: Heavy infections cause chronic irritation of the trachea and bronchi. Breathing becomes difficult. A whistling noise may accompany breathing, and a deep, wheezing cough may be heard, especially at night. There may be nasal discharge; dogs may hold their mouths open to breathe better. Infected dogs become emaciated and anaemic. Secondary bacterial infection can cause pneumonia.

Diagnostic Information: Typical Capillaria -like eggs appear in the faeces.

Control: Faecal material should be removed from animal quarters. None of the currently available anthelmintics are known to be effective against this worm.

Capillaria - egg