SA Metastrongyles

Question 1

Name four species of metastrogyles which can affect dogs and cats.

Answer 1

• Angiostrongylus vasorum
• Crenosoma vulpis
• Oslerus osleri
• Aelurostrongylus abstrusus

Question 2

Where in the body would adult Angiostrongylus vasorum be found?

Answer 2

Pulmonary arteries and right heart chambers

Question 3

How big would a Angiostrongylus vasorum be?

Answer 3

2cm

Question 4

Describe the morphology of adult Angiostrongylus vasorum.

Answer 4

Barber pole - reproductive and GI systems intertwine. Dorsal notch

Question 5

Name the intermediate hosts of Angiostrongylus vasorum.

Answer 5

Molluscs - slugs - Arion rufus

Question 6

Outline the lifecycle of Angiostrongylus vasorum.

Answer 6

Eggs hatch in the dogs lungs and are released into the pulmonary vessels they moult to L1, these are coughed up and swallowed. L1 are passed in the faeces and taken up by the intermediate host, which is then eaten by the dog. Larvae mature and to adults which migrate to the heart.

Question 7

What is the PPP of Angiostrongylus vasorum?

Answer 7

5-8 weeks

Question 8

Outline the migratory route of Angiostrongylus vasorum.

Answer 8

Migrates via blood, lymph, heart and pulmonary arteries

Question 9

How long do A. vasorum larvae spend in the intermediate host?

Answer 9

17 days

Question 10

How is A. vasorum transmitted to the definitive host?

Answer 10

L1-L3 in the slug or possibly free L3

Question 11

Name a minor paratenic host of A. vasorum.

Answer 11

Frog

Question 12

Outline the clinical signs associated with A. vasorum infection.

Answer 12

Respiratory - exercise intolerence, lethergy, soft moist cough, dyspnoea. Coagulopathies Fluctuating Haematoma Neuro Wt loss

Question 13

Which group of dogs are at higher risk of A. vasorum infection?

Answer 13

Young - up to 10 months

Question 14

Radiographic signs of A. vasorum include…

Answer 14

Patchy alveolar and interstitial pattern Cardiomegaly Enlarged pulmonary artery Need to differentiate from other lung worms via BAL and faecal examination

Question 15

How can A. vasorum infection be diagnosed?

Answer 15

BAL Faecal examination Antigen blood test Radiography Clinical signs

Question 16

Outline the treatment and control of A. vasorum.

Answer 16

Milbemycin oxime MOX, FBZ Corticosteroids Prophylactic anthelmintics Reduce exposure to fox and slug habitats

Question 17

Describe the morphology of Crenosoma vulpis.

Answer 17

Slender white worms 1.5cm Spiny cuticular folds

Question 18

Where can Crenosoma vulpis be found in the dog?

Answer 18

Mucus of trachea, bronchi and bronchioles

Question 19

Name two species of metastrongyle, on with a direct and one with an indirect lifecycle.

Answer 19

Direct - Oslerus osleri, Indirect - Angiostrongylus vasorum

Question 20

Where would adult Oslerus osleri be found in the definitive host?

Answer 20

In nodules in the trachea (particularly the tracheal bifurcation

Question 21

How is Oslerus osleri transmitted between dogs?

Answer 21

Through the faecal-oral route Through sputum - such as bitch grooming puppies

Question 22

What is the PPP of Oslerus osleri?

Answer 22

10-18 weeks

Question 23

How can Oslerus osleri infection be diagnosed?

Answer 23

Bronchoscopy to visualise nodules Larvae in faeces (low sensitivity)

Question 24

What clinical signs would be suggest Oslerus osleri infection?

Answer 24

Respiratory signs due to obstructive nodules - chronic cought, tracheo-bronchitis, exercise intolerence.

Question 25

What characteristic feature characterises Aelurostrongylus abstrusus?

Answer 25

S-shaped tail of L1 larvae

Question 26

Birds and mice act as paratenic hosts of which metastrongyle?

Answer 26

Aelurostrongylus abstrusus

Question 27

What clinical signs are assocaited with A. abstrusus?

Answer 27

Usually asymptomatic but can cause coughing and respiratory disease.

Question 28

What treatment would be used in an A. abstrusus infection?

Answer 28

FBZ