Pulmonary parasites

Question 1

Dictyocaulus viviparus clinical signs

Answer 1

Deep harsh cough
Tachypnoea
Squeaks & crackles during lung auscultation

Question 2

Dictyocaulus arnfeldi clinical signs & treatment

Answer 2

Main clinical sign is persistent cough & lung sounds

Clinical signs don’t respond to certain drugs

Tracheal wash may reveal worms

Treatment:
Ivermectin, Fenbendazole, Moxidectin

Question 3

Aelurostringylus abstrusus diagnosis & treatment

Answer 3

Diagnosis:
Larvae in faeces
Larvae in BAL fluid
Radiograph of lung

Treatment:
Fenbendazole, Ivermectin, Levamisole

Question 4

What are non-true lung worms

Answer 4

Only have lung phase during migration & residing tissue for adults aren’t lungs (commonly intestine)

Ascaris suum in pigs & Toxocara canis in dogs

Question 5

What is Dictyocaulus spp.

Answer 5

D viviparus (cattle, camelids, deer)

D filaria (sheep & goats)

D arnfeldi (donkeys & horses)

Adult lungworms live in trachea & bronchi causing parasitic bronchitis

Deposition of eggs/newly hatched larvae may lead to parasitic pneumonia

Question 6

Life cycle of cattle lung worm Dictyocaulus viviparus

Answer 6

Seen in cattle on permanent pastures used for seasonal grazing
Cattle exposed develop rapid immunity

1. Adult worms lay eggs in bronchioles
2. Eggs coughed up & swallowed by host & passed out in faeces
3. Eggs hatch & release L1 which develop into L3
4. L3 ingested by cattle & enter bloodstream & carried to lungs
5. Develop into L4 in bronchioles

Question 7

Life cycle of Angiostrongylus vasorum

Answer 7

Adults mainly live in pulmonary arteries
Life cycle indirect: dog definitive host, slug intermediate host
Becoming more widespread in UK due to increased fox urbanisation

1. Adult lays eggs in pulmonary capillaries
2. L1 coughed up, swallowed & excreted
3. L1-L3 develop in snail
4. Dog eats snail
5. L5 develop in mesenteric lymph nodes
6. Travel to pulmonary artery

Question 8

Life cycle of Aelurostrongylus abstrusus

Answer 8

1. Adults lay eggs in alveoli
2. L1 hatched in trachea & coughed up & swallowed
3. L1 passed in cat faeces
4. Enters intermediate host
5. L3 arrest in paratenic host
6. Paratenic host ingested by definitive host (cat)
7. Become L5 in alveoli