8 – Disease of Pleura & Intro to Pneumonia

Question 1

Chylothorax

Answer 1

• Accumulation of chyle (lymphatic fluid)
• ‘milky’ appearance (white, maybe pink ting)
• *rupture or damage to thoracic duct
• Commonly idiopathic
  o May have heart failure or neoplasms which obstruct the thoracic duct
• Dogs and cats

Question 2

Hemothorax

Answer 2

• Blood in thorax cavity
• No specific etiology
  o Trauma or ruptured neoplasms
• Can be associated with ingestion of anti-coagulant rodenticides

Question 3

Hydrothroax

Answer 3

• Edema in thorax cavity
  o Any causes of edema (heart failure or hypoproteinemia, lymphatic obstruction is possible)
• *R-sided heart failure=common

Question 4

Pleuiritis (pleuropneumonia)

Answer 4

• Not common by itself
• Infection/inflammation of the lining of pleural cavity
• *extension of pneumonia (bacterial infection from adjacent lung)
• Primary lesion in: *feline infectious peritonitis (FIP)

Question 5

FIP (Feline Infectious Peritonitis)

Answer 5

• Accumulation of fluid in thorax cavity
  o THICK and viscous

Question 6

Pneumothorax

Answer 6

• Presence of air in pleural space (atelectasis)
• Result of penetrating wound
• Detected at necropsy by puncture of diaphragm from abdominal side

Question 7

Pyothorax

Answer 7

• Accumulation of neutrophil rich (suppurative exudate)
• *often associated with a PENETRATING wound

Question 8

Mesothelioma

Answer 8

• ONLY tumour of the pleura (malignant)
• *tumour of the mesothelium
• NOT common in animals
• People: exposure to asbestos (develop over decades) NOT case in animals
• *grows ALONG the pleural surfaces

Question 9

Overview of patterns of pneumonia (BASED ON WHERE INFLAMMATION IS OCCURING ON A MICROSCOPIC LEVEL)

Answer 9

• Bronchopnemnoia=BACTERIAL
• Interstitial lung disease (pneumonia)=VIRAL
• Bronchointerstitial pneumonia=VIRAL
• Embolic pneumonia=EMBOLISMS
• Airway disease=HYPERSENSITIVITIES

Question 10

Bronchopneumonia

Answer 10

• Inflammation is centered on ALVEOLI and small airways
  o Fill with inflammatory cells

Question 11

Bronchopneumonia causes

Answer 11

• Highly suggestive of BACTERIAL INFECTION
• Often start with a viral infection, then secondary bacterial infection
  o Bacterial infection=worse=causes disease

Question 12

Bronchopneumonia grossly

Answer 12

• RED in cranioventral portion
• May be covered by fibrin
• First area that the particle ‘falls’
• Purple-red

Question 13

Lobar or lobular bronchopneumonia

Answer 13

• Effects all a lung lobe OR just individual lobules within the lung
• *more severe if a whole lobe

Question 14

Bronchopneumonia affecting dorsal portion of lung

Answer 14

• In PIGS

Question 15

Aspiration pneumonia

Answer 15

• *black and green colour
• Often unilateral
• Cranial-ventral
• Ruminants=smells bad

Question 16

Aspiration pneumonia can be associated with

Answer 16

• Vomiting
• Regurgitation
• Swallowing issues
• Iatrogenic

Question 17

Severe cases of bronchopneumonia

Answer 17

• Bronchiectasis
• Fibrin adhesions
• Could get sequestrum formation: more common for lesions caused by Mycoplasma bovis

Question 18

Bronchiectasis: resolution

Answer 18

• Looks like an abscess, but is a small airway (bronchiole) that is PLUGGED and FILLED with an exudate
• More cylindrical (since in an airway)

Question 19

Interstitial lung disease (aka interstitial pneumonia)

Answer 19

• Lesion is within WALL OF ALVEOLAR SEPTA
  o Widened alveolar septa

Question 20

Interstitial lung disease causes

Answer 20

• VIRUSES
• Toxins
• Septicemia’s
• Thermal injury, smokie inhalation

Question 21

Interstitial lung disease grossly

Answer 21

• DIFFUSELY affected
• pale
• Lung that fails to collapse (INFLATED)
  o Rib impressions
  o Widened inter-lobular septa
• HEAVIER
• FIRMER
• RUBBERY appearance

Question 22

Interstitial lung disease resolution

Answer 22

• Wide spread damage of type I pneumonocytes
• *when replaced, get type II pneumonocytes=impaired gas exchange for a while

Question 23

Bronchointerstitial pneumonia (‘subcategory’)

Answer 23

• ALVEOLAR SEPTA(bronchiolar) and ALVEOLI

Question 24

Bronchointerstitial pneumonia causes

Answer 24

• VIRAL
• Not common

Question 25

Bronchointerstitial pneumonia grossly

Answer 25

• Widened interlobular septa
• Areas of dark red in cranioventral
• *broncho and interstitial pneumonias

Question 26

Embolic pneumonia

Answer 26

• Embolism in the lungs
• *randomly scattered areas of inflammation within the lung
• Commonly confused with a tumour
• *suppurative lesions or abscesses
• Maybe granulomatous lesions (fungal origin)

Question 27

Embolic pneumonia causes

Answer 27

• Ex. liver abscess in cattle
  o Rupture into big vessel on venous side and then ‘shower’ into the lungs

Question 28

Embolic pneumonia grossly

Answer 28

• RANDOM polka dot (multifocal pattern)
• Acute: hyperemia

Question 29

Airway disease (aka bronchitis, bronchiolitis)

Answer 29

• Inflammation in smaller airways NOT the alveoli or alveolar septa
  o AIRWAY EPITHELIUM DAMAGE
• Result of smooth muscle contraction and accumulation of material within airways

Question 30

Airway disease causes

Answer 30

• VIRUSES
• HYPERSENSITIVITY REACTIONS
• Poor living/pollution
• Less commonly bacteria

Question 31

Airway disease grossly

Answer 31

• Little areas of white (‘small cylinders’)
  o Inflammation in very small airways
• NOT very dramatic lesions

Question 32

Airway disease resolution (chronic)

Answer 32

• Bronchiolitis obliterans
  o Damage lining of airway epithelium, when heals=scar underneath it (mass of fibrous tissue)=impaired airflow
   Atelectasis
• Squamous metaplasia
• Increased fibrosis (cor pulmonale)

Question 33

Cor pulmonale

Answer 33

• Anything that causes widespread inflammation and then healing and repair in the lungs
• Fibrosis in lung=less elastic=increase resistance
  o Over time, can lead to R-sided heart failure as it is very difficult to pump the blood