Lungworms

Crenosoma vulpis With Cuticular Annulations

• Found in the lungs or adjacent blood vessels.
• L1 in faeces.
• Kinky tails= diagnostic features. 
• Indirect lifecycles with mollusc intermediate hosts.
• Lymphotracheal migration. 

Metastrongylus Apri

Notice the small bulb at the end
of the tail.

• Pigs in the small bronchi and bronchioles.
• White worms up to 6cm long.
• Live larvae when faeces passed with a bulb at the end of the tail.
• Not very pathogenic.
• Decreased weight and exacerbates other respiratory pathogens.
• L1 is ingested by the earthworm which is the intermediate host. L1-L3 development in the earthworm. L3 is the infective stage. 
• Outdoor pig problem- 4-6 months fenbendazole in feed. 
• PPP= 4 weeks. 

Muellerius Capillaris

• Common.
• Non pathogenic in sheep but pathogenic in goats.
• Hair like adults in the lung parenchyma presenting as eosinophilic grey-green nodules. 
• L1 in faeces.
• Intermediate host= slug/snail.
• No anterior cuticular knob as in dictyocaulus filaria but has a kink and spike on the tail. 
• D.filaria= cuticular knob and straight tail.

Oslerus Osleri

• Direct life cycle. 
• Form tracheal nodules.
• Passed from bitch to pup via L1 in sputum which is the infective stage.
• Commonly seen in young dogs with symptoms of tracheo-bronchitis and a cough.
• Bronchoscopy can identify the nodules as there is a low sensitivity to faecal larvae. 
• Larvae possess an s-shaped tail.
• L1 moults to L2 in the small intestine and then migrates via the lymphatics and vascular system to the lungs. 

Crenosoma Vulpis

• Fox reservoir host- affects the dog.
• 1.5cm and white. Spiny cuticular folds and a straight tail.
• Mucus of trachea, bronchi and bronchioles.
• L1 to L3 in snails.
• Seasonality important. 

Angiostrongylus Vasorum 

• Highly pathogenic.
• Resides in the pulmonary artery and right atrium and is around 2cm big.
• Intermediate hosts are both slugs and snails.
• Paratenic host is the frog (no development takes place but another method of where the dog may eat the frog thus infecting the host).
• L1 is released from the adult female, and breaks through the pulmonary capillaries into the alveoli and trachea. These are then coughed up, swallowed and pass out as L1 in the faeces. 
• L1 in faeces and BAL where samples should be repeated. 
• L1-L3 occurs in the snail/slug. They are then ingested by the dog. The L3 migrates via the blood and lymph to the heart and pulmonary arteries.
• PPP= 5-8 weeks.

Clinical Signs 

• Often asymptomatic for a large period of time followed by sudden death. 
• Respiratory.
• Coagulopathies.
• Dyspnoea.
• Weight loss.
• Flunctuating haematoma.
• Bleeding disorders.

Diagnosis

• Clinical signs.
• Radiography interstitial pattern- enlarged heart and pulmonary artery. Patchy alveolar and interstitial pattern.
• L1 in respiratory tract and take repeat samples. 
• Infection foci extending due to fox reservoir host and dog movements. 

Treatment 

• Milbemycin Oxime.
• Moxidectin.
• Fenbendazole.
• Corticosteroids. 

Aelurostrongylus Abstrusus

• Cats.
• Adults in the lung parenchyma.
• L1 in faeces have a S shaped tail.
• Snail horse and mouse/bird paratenic host.
• Aymptomatic.
• Cough/respiratory disease.
• Treatment= fenbendazole.
• Snail eaten by rodent/bird= paratenic host so no development in this host.

Larvae in H & R from lung parenchyma