VMED 02610: Pathobiology II Systemic Pathology – Respiratory System Lecture 4

Lung Lobe Torsion occurs rarely in what animal

dogs and cats

But we mentioned that Lung Lobe Torsion rarely occurs in dogs and cats but animal is actually predisposed

Afghan hounds are predisposed

Lung Lobe Torsion leads to what

to infarction, pleural effusion, and dyspnea

What is Hyperemia

 Increased blood flow

Hyperemia is associated with what disease

 Associated with acute inflammation

Congestion is associated with what

Associated with left-sided heart failure

What does Congestion look like grossly in the lungs

Lung is dark red, but not firm

When do we find congestion in the lungs

Common incidental finding at necropsy

Pulmonary edema results in (in Increased permeability)

 Results in leakage of protein-rich fluid

What causes pulmonary edema ( Increased permeability)

Causes include infectious agents, corrosive gasses, and toxins

Pulmonary edema damages what ( Increased permeability)

 Damage to type I pneumocytes and/or capillary endothelium

Pulmonary Edema under Increased Hydrostatic Pressure usually occurs when

 Usually from left-sided heart failure (cardiogenic edema)

Pulmonary Edema under Increased Hydrostatic Pressure why does it occur what are the causes (under increased hydrostatic pressure)

 Generally lower protein content than with edema from increased permeability

 Other causes include iatrogenic fluid overload and acute brain injury (neurogenic edema)

Pulmonary Edema under Increased Hydrostatic Pressure why does it occur what are the causes (under decreased osmotic pressure)

 Less important the other two mechanisms

 From hypoproteinemia

Pulmonary Hemorrhage causes what

 Causes include sepsis, ruptured aneurysms, trauma, and clotting abnormalities

Pulmonary Hemorrhage can lead to what in horses

Exercise-induced pulmonary hemorrhage in horses

Pulmonary Emboli does what to eh lungs

 Lungs trap emboli from systemic venous circulation

Non-septic emboli includes what

tumors and fat

Septic emboli can arise from (this is under pulmonary emboli)

valvular endocarditis, other sites of infection (liver), or thrombosed vessels

What are the three mechanisms of pulmonary edema (circulatory disturbance)

• increased hydrostatic pressure

• increased capillary permeability

• decreased lymphatic drainage

Thrombi form because of

Virchow’s triad

What are the components of Virchow’s triad

1. Blood Flow Stasis (Slow Circulation)

2. Endothelial Damage (Vessel Wall Injury)

3. Hypercoagulability (Blood Clots Too Easily)

Pulmonary Thrombus Causes include

Dirofilaria immitis in dogs and DIC

Glomerular amyloidosis in dogs leads to

proteinuria and loss of antithrombin III, increasing the risk of thrombosis

Is Pulmonary Infarction rare or common

its rare

Pulmonary Infarction occurs when

Occurs only when lung is already compromised

Pulmonary infarction is most common in what organ system

Most common in caudal lung lobes

Can Pulmonary Infarction be hemorrhagic ?

Yes: Hemorrhagic and often bulge from pleural spaces

What are the two main causes of Pulmonary Hypertension

1. Increased blood flow from the right heart to the lungs (ventricular septal defect)

2. Increased resistance in the pulmonary vascular system

Pulmonary Hypertension leads to what

Leads to arteriosclerosis and potentially to right-sided heart failure

Pulmonary Hypertension occurs due to

 High Altitude Disease

 Disease of cattle pastured in high altitudes

 Also called brisket disease

Chronic hypoxia leads to what

vasoconstriction, chronic hypertension, and right-sided heart failure

Bronchial Tree causes what clinical sign

• Sneezing and coughing

• Mucociliary apparatus

What Immunoglobulins do bronchial tree produce

Immunoglobulins (esp. IgA)

Alveoli create what

Alveolar macrophages

Alveolar lining liquid contain

IgG, lysozyme, lactoferrin, and complement

Phagocytosis is less efficient than

mucociliary blanket

Which lung is normal: showing the distribution pattern of bronchi and brochides

Which is a suppurative bronchiopneumonia

Which is fibrinous bronchopneumonia

Which one is intersitial (diffuse) pneumonia (viral influenza)

Which one is embolic pneumonia

Which one is granulomatous pneumonia (TB, deep seated mycoses)

Which one is a tumor metastases from a nonpulmonary primary site

Which one is a primary lung tumor with secondary metastases

Which one is a locally extensive dorsal diaphragimatic pnemonia

Which one is verminous (parastic) pne

WHat is aspiration pneumonia (improper stomach tubing)

Which one of these photos is the hypostatic congestion (prolonged recumbency)

Bronchopneumonia is usually what bacteria or fungal

 Usually bacterial

1. Mannheimia hemolytica

2. Pasteurella multocida

3. Actinobacillus pleuropneumoniae

4. Streptococcus sp.

Pulmonary defenses must be compromised by

shipping stress, chilling, viral infections, metabolic disorders, etc.

in Bronchopneumonia Inflammation centered on

terminal bronchioles and adjacent alveoli

Bronchopneumonia is described by

Typically suppurative, fibrinous, or necrotizing

What are the gross lesions for Acute Bronchopneumonia

 Lung is consolidated, firm, rubbery, dark red (red consolidation) and not depressed

 Mucopurulent exudate can often be expressed from airways

 Fibrin may be present on pleural surface

What are the histologic lesions of bronchopneumonia

 Alveolar spaces contain neutrophils, erythrocytes, fibrin, edema fluid, and a few macrophages

 Capillaries are distended with erythrocytes (hyperemia)

 Alveolar lining cells may become necrotic

 Bronchiolar epithelium may be normal, necrotic, or hyperplastic

Subacute to Chronic Bronchopneumonia what is the gross lesion description

Lung is grey-red to grey (grey consolidation) and very firm

Grey color is due to what (in Subacute to Chronic Bronchopneumonia)

more macrophages and fewer erythrocytes