Dictyocaulus filarial (1)

Question 1

What are the hosts?

Answer 1

Goats

Sheep

Question 2

Describe an adult

Answer 2

Long, slender, white

3-8 cm

In bronchi and trachea

Question 3

Describe the larvae

Answer 3

L1 recovered in feces

400-500 micro m long

Bronchoalveolar lavage can be used to recover eggs and larvae

Question 4

Describe the life cycle

Answer 4

Direct

L1 found in feces instead of eggs

L3 infective

L3 migrates through intestinal wall via the lymph and blood, travels to lungs

Mature in trachea and bronchi

Question 5

What is the site of infection?

Answer 5

Bronchi and trachea

Question 6

Describe the Pathogenesis

Answer 6

Pathology associated with bovine infection UNCOMMON

Unthriftiness

Penetration
     - Larval migration
     - No clinical signs
Prepatent
     - Larvae develop to adults in lungs
     - Alveolitis and bronchitis
Patent
     - Presence of adult worms in lungs
     - Bronchitis and pneumonia
Post patent 
     - If animal survives, recovery starts
     - Relapse can occur; entire lungs diseased

Goats suffer no more than sheep

No strong immunity development

Question 7

Describe the clinical signs

Answer 7

Prepatent phase alveolitis followed by bronchiolitis

Bronchitis

Pneumonia - result of aspirated eggs + L1

Edema and emphysema

Alveolar epithelialization of entire lung lobes

Frequent bouts of coughing at rest

Squeaks and crackles over posterior lung lobes

“Air hunger” position of mouth breathing with the head and neck outstretched

Question 8

How do you diagnose?

Answer 8

Clinical signs

History

Endemic area

Identification of L1

Necropsy

Question 9

How do you treat and prevent?

Answer 9

Anthelmintics

Management

Question 10

What is the common name?

Answer 10

Husk, Hoose, Verminous Pneumonia