Scientific name: Dictyocaulus arnfieldi
Common name: Lungworms

Description: Adult lungworms are long and slender, measuring between 25 and 70 mm (2 inches). Lungworms irritate the lining of the small air sacs in the lungs and may cause an infected horse to develop a severe cough and other signs of bronchitis. Adult and older horses usually develop a resistance to lungworms. Foals, however, are susceptible to infection due to their lack of immunity.

Life Cycle: Horses ingest lungworm eggs that have passed through the manure of an infected horse and into a food source. Once a horse has ingested the eggs, infective larvae work through the walls of the intestine and into the circulatory system. They are carried through the circulatory system into the lungs where they mature. Female lungworms lay eggs that are passed with manure.

Symptoms: Horses and foals infected with lungworms may develop parasitic bronchitis, a severe or persistent cough and have difficulty breathing.

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