Respiratory system pathology Flashcards
What can cause airway inflammation?
Infectious agents
Allergic disease
Neoplasia
Physical injury - foreign body
What occurs during acute inflammation?
Detachment of cells Increased secretions Oedema Vasodilation Leukocyte emigration
What are the different types of resp airway discharges/exudates?
Serous
Catarrhal
Purulent
Fibrinous/fibrinonecrotic
What causes catarrhal airway discharge?
Increase in mucous production from goblet cells
What causes purulent airway discharge?
Bacterial infection - contains leukocytes
What causes fibrinous/fibrinonecrotic airway discharge?
Severe inflammation/mucosal injury with fibrin exudate
What occurs during chronic inflammation of the airways?
Increased mucus production due to hypertrophy/hyperplasia of seromucus glands and goblet cells
Mucosal thickening
Increased resistance
Loss of mucociliary apparatus
What is Bronchiectasis?
Bronchus full of exudate causes obstruction
The enzymes within exudate destroy the bronchial wall
What may form as a result of chronic airway inflammation?
Fibrous inflammatory polyps
What are the 4 different types of pneumonia?
Bronchopneumonia
Interstitial pneumonia
Granulomatous pneumonia
Embolic pneumonia
What type of pneumonia is the most common?
Bronchopneumonia
What can cause bronchopneumonia?
Bacteria
Viruses
Aspiration
What is the distribution of bronchopneumonia?
Cranioventral distribution
What occurs during acute bronchopneumonia?
Infection causes inflammation
Suppurative/fibrinous exudate accumulates within alveolar spaces/bronchioles/lobules
What can chronic bronchopneumonia result in?
Fibrosis
Airway obstruction
Bronchiectasis
Abscess formation
What is interstitial pneumonia?
Injury to lung parenchyma – alveolar wall
Hyperaemia and exudate in alveoli
What makes up the alveolar wall/lung parenchyma?
Basal lamina
Endothelial cells
Type 1 pneumocytes
What is the distribution of interstitial pneumonia in the lungs?
Diffuse/generalised
What can cause interstitial pneumonia?
Inhalation/haematogenous spread of Viruses Parasites Toxins - fog fever Allergens - fungal spores Septicaemia
What histological change occurs during interstitial pneumonia?
increased Type 2 pneumocytes at the margins of the alveoli – to repair damaged Type 1 pneumocytes
What does chronic interstitial pneumonia cause?
Thickened alveolar walls - fibrosis
Persistent type 2 pneumocytes
What causes embolic pneumonia?
Bacteria from septic emboli
What is the route of entry for embolic pneumonia?
Haematogenous
What is the distribution of embolic pneumonia?
Random foci
What are some sources of septic emboli?
Liver abcesses
Bacterial endocarditis
Mastitis
Endometritis
What causes granulomatous pneumonia?
Agents that are resistant to phagocytosis/inflammatory response so are persistent in tissues
What are some examples of agents that cause granulomatous pneumonia?
Mycobacteria (TB)
Actinomyces
Lungworms
Feline infectious peritonitis
What is the distribution of granulomatous pneumonia?
Variable
Focal/multifocal
Nodular
What are the general characteristics of malignant sinonasal tumours?
Slow growing
Space occupying
Invasive and destructive
With mucopurulent discharges
What non neoplastic nasal mass is found in horses?
Progressive ethmoid haematoma
What lung tumour can be caused by a virus in sheep?
Ovine pulmonary adenocarcinoma
Jaagsiekte
What can cause pulmonary oedema?
LsCHF - increased hydrostatic pressure
Inflammation
Reduced lymphatic drainage
What can cause pulmonary haemorrhage?
Inflammation Neoplasm Progressive ethmoid haematoma Exercise induced pulmonary haemorrhage in horses Trauma
Where are paranasal sinus cysts located in horses?
Cyst at maxillary sinus/ ventral turbinates
What part of the trachea is extrathoracic?
Cervical trachea
What part of the trachea is intrathoracic?
Thoracic trachea
In dogs with tracheal collapse, what does inspiration cause?
Collapse of cervical trachea
In dogs with tracheal collapse, does expiration cause?
Collapse of the thoracic trachea
What are the primary features of BOAS?
Stenotic nares Elongated soft palate Large tongue Turbinate protrusion Hyperplastic trachea
What side does laryngeal paralysis occur on in horses?
Left side
What causes laryngeal paralysis?
Degeneration of recurrent laryngeal nerve
atrophy of cricoarytenoid muscles
What causes Sino-nasal Aspergillosis?
Aspergillus fumigatus
What does Sino-nasal Aspergillosis cause?
Aflatoxin production
Inflammatory response
Turbinate and bone destruction
What are the clinical signs of Sino-nasal Aspergillosis?
Mucopurulent discharge, epistaxis, nasal depigmentation
How can you treat Sino-nasal Aspergillosis?
Mechanical debridement +/- trephination
Topical antifungal – clotrimazole
Are nasal tumour benign or malignant
Malignant - 80-90%
Locally invasive - cribiform plate
What is the most common nasal tumour in dogs?
Adenocarcinoma
What is the most common nasal tumour in cats?
Lymphoma
How can you treat nasal tumours?
Radio/chemotherapy +/- NSAIDs
What is the cause of chronic rhinosinusitis in cats?
Bacterial/Viral/ idiopathic
How can you treat chronic rhinosinusitis in cats?
Bacteria – Doxycycline
Viruses – Famciclovir, Bromhexine, NSAIDs
What is chronic rhinitis in dogs?
Allergen/ irritant/ immune mediated gradual progressive nasal disease
How can you treat chronic rhinitis in dogs?
Reduce exposure
Steam/nebulize
Antihistamines
Doxycycline (bacteria)
What is a cough?
Sudden expiratory effort against closed glottis (protective reflex)
What is coughing controlled by?
Cough centre (Medulla Oblongata)
What are the 4 regions of the respiratory system that are affected during dyspnoea?
Upper resp tract
Lower resp tract
Pulmonary parenchyma
Pleural space
Where do obstructive disorders affect in the resp tract?
Upper/lower resp tract
Where do restrictive disorders affect in the resp tract?
Pulmonary parenchyma
Pleural space
What are haematological causes of tachypnoea?
Reduced O2 carrying capacity (anaemia, MetHb)
What are metabolic causes of tachypnoea?
Compensatory mechanism to acidosis, muscular weakness
What causes inspiratory dyspnoea?
Dynamic upper airway obstruction
What causes expiratory dyspnoea?
Dynamic lower airway obstruction
What sounds are made during dynamic upper airway obstruction/inspiratory dyspnoea?
Stridor (roar) and stertor (snoring)
What sounds are made during dynamic lower airway obstruction/espiratory dyspnoea?
Wheezes
Where does stertor originate from?
Nasopharyngeal
Nasal
Where does stridor originate from?
Larynzz
What do crackles and/or wheezes indicate?
Adventitious Lung sounds - pulmonary parenchyma
What does shallow breathing and reduced/muffled lung sounds indicate?
Pleural space disease
What type of dyspnoea does BOAS cause?
Inspiratory obstructive dyspnoea
What type of dyspnoea does pneumonia cause?
Restrictive mixed pattern dyspnoea
What is canine chronic bronchitis?
Chronic bronchial inflammation with over secretion of mucous
How do you diagnose canine chronic bronchitis?
X ray - doughnuts and tramlines
Bronchoscopy, Bronchioalveolar Lavage
What does canine chronic bronchitis cause in the lungs?
Obstructive dyspnoea - mucous
Emphysema - air trapped in alveoli
Altered mucociliary escalator
Inflammation
How do you treat canine chronic bronchitis?
Weight management
Avoid allergens/irritants Bronchodilators - theophylline, salbutamol inhalant
Inhaled corticosteroids - fluticasone
What diseases are in feline lower airway disease?
Feline asthma and feline chronic bronchitis
What does feline lower airway disease cause?
Chronic bronchial inflammation
Mucous hypersecretion
BRONCHOCONSTRICTION of smooth muscle (dogs cant do this)
What is the cause of feline lower airway disease?
Type I hypersensitivity - IgE mediated
Histamine and serotonin production by mast cells
How is feline lower airway disease diagnosed?
Imaging, bronchoscopy, BAL
How is feline lower airway disease treated?
Bronchodilators - terbutaline
Corticosteroids - Dexamethasone
What is the Angiostrongylus Vasorum migration?
Migration from intestine to heart to alveoli
What symptoms does Angiostrongylus Vasorum cause?
Chronic cough, cor pulmonae, syncope, pulmonary hypertension
What is the distribution of Angiostrongylus Vasorum in the lungs?
Peripheral
How do you treat Angiostrongylus Vasorum?
Moxidectin
Fenbendazole
How do you diagnose bacterial pneumonia?
Haematology (neutrophilia)
C-reactive protein - inflammation marker
Bronchoscopy, BAL
What is important when treating bacterial pneumonia?
Wait for culture result - high resistance risk
How do you treat aspiration pneumonia?
IV amoxicillin and clavulanic acid
How do you treat septic pneumonia?
fluoroquinolones + ampicillin/clindamycin
What is Eosinophilic Bronchopneumopathy?
Eosinophilic inflammation of lungs and bronchi
How does Idiopathic Pulmonary Fibrosis present?
Interstitial fibrosis - honeycomb appearance
Not at all bronchial pattern
