Angiostrongylus vasorum

ANGIOSTRONGYLUS VASORUM

• Infects dogs and foxes.
• A typical metastrongyloid, with the adult worms living in the pulmonary arteries and the right side of the heart.

Life-Cycle

Adults (approximately 2cm), produce anticoagulants to reduce thrombus formation leading to coagulation disorders:

→ eggs laid into pulmonary arteries

→ trapped in lung capillaries

→ larvae (with merastrongyloid kinky tail) hatch out

→ alveoli (causing a small injury)

→ trachea

→ swallowed

→ passed in faeces

→ slug (intermediate host)

→ eaten by dog or fox (final hosts)

→ larvae migrate via mesenteric lymph nodes

→ blood stream

→ heart.

Epidemiology

Once restricted to Southern Ireland and Cornwall, this lungworm is spreading across the British Isles and is now endemic in the South-East. The fox may act as a reservoir of infection.

Angiostrongylosis

• Clinical signs of angiostrongylosis are associated with:
  • accumulating lung damage caused by eggs and larvae (respiratory distress)
  • coagulation disorders caused by adult worms (bruising, haematomas, e.g. in spinal cord)
• Diagnosis: demonstration of large numbers of L1 in faeces (with Barmann technique).

Treatment of Lungworms in Dogs and Cats

• Angiostrongylus vasorum is easy to treat with suitable anthelmintics, but the others require high daily doses of benzimidazoles for 3-7days.
• Two or more courses of treatment may be necessary (with a rest period between each).