Aelurostrongylus abstrusus

Also known as:

Cat lungworm

Scientific Classification

Class	Nematoda
Superfamily	Metastrongyloidea

Hosts

Intermediate hosts: Molluscs, including snails and slugs, as well as paratenic hosts, including rodents, birds, amphibians, and reptiles.

Definitive host: Cat.

Identification

A. abstrusus are small parasites, measuring around 1cm in length. The worms are long and thing, and the male has a bursa, but it is small and poorly developed.

Life Cycle

This is an indirect lifecyle, involving two intermediate hosts, and a definitive host. The female is ovo-viviparous, and passes L1 within the host faeces. The L1 then infect the molluscs, and later develop into L2, the infective L3. The paratenic host ingests the molluscs. The cat, acting as the definitive host then ingests the L3, and becomes infected with the parasite.

The larvae then travel to the lungs via the lymphatic system or the bloodstream. These can be seen as nodules on the lungs. They then hatch out, and ar coughed up and swallowed. The parasite enters the alimentary tract, and is passed out in the faeces.

Clinical

Aelurostrongylosis

• Often asymptomatic; serious respiratory problems usually due to deficient immunity.
• Prognosis poor.
• Post mortem examination reveals greenish nodules in lungs.
• Histopathology diferentiates these from tuberculosis.

• Infections often asymptomatic, but can cause serious respiratory problems, especially in immunocompromised cats.

Fenbendazole is licensed for treatment.

• Live in lung parenchyma and small bronchioles
• Grossly:
  • Firm yellow nodules scattered throughout parenchyma, more frequently at periphery
• Microscopically:
  • Eggs and larvae in the alveolar spaces cause a foreign body type reaction (surrounded by mononuclear cells and giant cells)
  • Submucosal gland hypertrophy and smooth muscle hypertrophy in airway and vessel walls
• Associated clinical signs are mild although heavy infestations may -> chronic coughing
• The airway eosinophilia which may be detected can be confused with a diagnosis of asthma