Lung disease- interstitial disease

Question 1

What is lungworm in dogs

Answer 1

angiostrongylus vasorum
Is a vascular worm- the adults live in the pulmonary arteries

Question 2

Describe the hosts of Angiostrongylus vasorum

Answer 2

Definitive host= dogs
Intermediate= slugs/snails
paratenic host= frogs

Question 3

Describe the lifecycle of angiostrongylus vasorum

Answer 3

L1 in faeces
L1-L3 develop in slug/snail
Dog eats slug/snail or secretion/faeces
L5 mesenteric lymph nodes
Migration via lymphatics to HP vein/liver
Adult in pulmonary artery
Eggs in pulmonary capillaries
L1 penetrates capillaries and alveolar wall
L1 coughed up and swallowed

Question 4

List 5 clinical signs of angiostrongylus vasorum

Answer 4

most common= breathlessness/ cough
bleeding
neuro signs
dyspnoea
tachypnoea

Question 5

What causes the clinical signs of angiostrongylus vasorum infection

Answer 5

larval migration through lung airway

Question 6

Egg deposition/ the presence of L1 A. vasorum leads to:
a) Type III hypersensitivity
b) complement activation
c) granuloma formation

Answer 6

c) granuloma formation
* And also pulmonary inflammation and pulmonary arteriolar vasoconstriction which contributes to pulmonary hypertension.
* There is end arteritis and fibrosis of vessels.

Question 7

Adult antigens of A. vasorum cause:
a) pulmonary inflammation and granuloma formation
b) Type III hypersensitivity and complement activation

Answer 7

b) Type III hypersensitivity and complement activation
This leads to immune infiltrate into the lungs and other tissue

Question 8

Why might it be hard to diagnose A. vasorum ?

Answer 8

Larvae are intermittently shed in faeces
Take a pooled sample to try and minimise the chances of this

Question 9

Describe how you can diagnose angiostrongylus vasorum

Answer 9

pooled faecal sample –> L1 in faeces and flotation techniques
L1 in BAL fluid
SNAP tests
PCR on BAL/ pharynx swabs
Supportive evidence: radiographs may show alveolar infiltartes

Question 10

Describe the radiographic changes you may see with angiostrongylus vasorum

Answer 10

mixed alveolar and interstitial pattern
there is haemorrhage into the alveoli and larval migration through the interstitium

Question 11

List 2 licensed treatments for A. vasorum in dogs

Answer 11

Imidacloprid + moxidectin
Milbemycin oxime + praziquantel

Question 12

What are the risks associated with treatment of A. vasorum ?

Answer 12

There is danger associated with treatment - killing lots of parasites at once, releasing lots of antigens at once and thereby provoking host response
Clotting problems may persist after treatment

Question 13

Describe how to prevent Angiostrongylus vasorum

Answer 13

moxidectin + imidacloprid
treatments in the PPP prevents establishment of the adult parasites

Question 14

What is the signalment for interstitial pulmonary fibrosis

Answer 14

westies and other terriers
middle aged to older dogs- because progressive disease
uncommonly seen in cats

Question 15

List 5 things in the history suggestive of interstitial pulmonary fibrosis

Answer 15

subtle onset
Chronic breathlessness which is slowly progressive
Coughing can be a feature
Exercise intolerance
Owner may notice cyanosis

Question 16

List 2 clinical exam findings that you may get with interstitial pulmonary fibrosis

Answer 16

crackles throughout the lung fields
prolonged expiratory phase with expiratory effort

Question 17

List 3 things you may see on thoracic radiography with intersitial pulmonary fibrosis

Answer 17

generalised interstitial pattern
+/- right sided cardiomegaly
+/- pulmonary hypertension

Question 18

Describe how you diagnose intersititial pulmonary fibrosis

Answer 18

suggestive clinical signs = Diffuse crackles on auscultation, dyspnoea, coughing
Thoracic radiographs- generalised interstitial lung pattern
Bronchoscopy - rules out other inflammatory conditions
Lung biopsy is the only definitive method- not really done

Question 19

How do you treat interstitial pulmonary fibrosis

Answer 19

avoid collars and smoke
inhaled therapy= bronchodilators, corticosteroids
oral therapy= bronchodilators, corticosteroids
Management of pulmonary hypertension= phosphodiesterase inhibitors = Sidenafil

Question 20

Describe the prognosis for interstitial pulmonary fibrosis

Answer 20

guarded as progressive and generally seen in later stages
long-term palliation of clinical signs
dogs will continue to cough

Question 21

Describe how metastatic lung disease may present

Answer 21

rarely cause coughing if secondary tumour
often incidental finding

Question 22

How will neoplasia show up on a radiograph

Answer 22

well demarcated soft tissue opacity

Question 23

Why doees interstitial pulmonary fibrosis lead to right sided heart enlargement

Answer 23

increased pressure in the lungs leads to pulmonary hypertension and this causes right sided enlargement

Question 24

Treatment for metastatic lung tumours

Answer 24

can do surgery ifjust 1 present
chemotherapy can be given locally