Respiratory disease Flashcards
What diagnosis is strongly correlated with paradoxical breathing?
Pleural space disease
What breed is associated with congenital laryngeal malformation?
Norwich Terrier
Which breeds are associated with feline asthma?
Siamese
Havana
Ddx cough
Airway narrowing during expiration
Pleural space disease (D>C)
Cardiomegaly
Intrinsic airway narrowing secondary to dynamic small airway disease
Bronchitis
Asthma
Tracheal collapse
Restrictive lung disease
What are the possible causes of a restrictive breathing pattern?
Bronchopneumonia
Pulmonary fibrosis
Pleural space disease
What are the CT findings consistent with IPF?
Ground glass opacities, parenchymal bands, honeycombing, peribronchial vascular interstitial thickening, traction bronchiectasis with predominantly sub pleural distribution
How is lung scintigraphy performed depending on the region of interest?
IV radionucleatides - perfusion
Inhaled radionucleotides - ventilation
Simultaneous - ventilation/perfusion ratio
What is the most sensitive and specific test for documenting PTE?
Scintigrophy
Ddx hypoxaemia
Low partial pressure inspired oxygen, alveolar hypoventilation, ventilation-perfusion inequality, R => L shunt, diffusion impairment
What PaO2 is consistent with hypoxaemia?
<80mmHg
What upper airway abnormality has been described to develop secondary to IPF in WHWT?
Tracheal collapse
What other imaging findings are commonly associated with cranial lung lobe herniation?
Collapse of intrathoracic trachea and major bronchi
Redundant dorsal tracheal membrane
What tracheal tumours are found in a) young dogs and b)older dogs and cats?
a) Osteochondroma
b) MCT, SCC, adenocarcinoma, OSA, extra medullary plasmacytoma, leiomyoma, fibrosarcoma
What are the causes of parasitic tracheal granuloma in a) dogs and b) cats
a) Oslerus osleri, FIlaroides
b) Cuterebra
What are the limitations of culture and PCR for diagnosing bordetellosis in dogs?
Bb has been regularly isolated from healthy dogs by culture and PCR of upper airways and lungs
Positive could be incidental, indicate carrier state or infection
What is the characteristic cytological finding in bordatella infection?
Pleomorphic cocci or coccobacilli adhering to cilia of epithelial cells
What is the treatment of choice for bordetella infection? What about in unresponsive cases?
Doxycycline
Nebulised gentamicin
How is chronic bronchitis defined?
Chronic airway inflammation without any identifiable primary cause
What are the diagnostic criteria of chronic bronchitis?
Chronic cough
Evidence of excessive mucus
Exclusion of other chronic cardiopulmonary disease
Which breeds are predominantly associated with eosinophilic bronchopneumopathy
Huskies and Malamutes
What abnormalities can be seen in association with primary ciliary dyskinesia?
Otitis media, infertility in females, asthetoteratospermia in males, hydrocephalus, renal fibrosis or dilation of renal tubules
Situs inversus
What is bronchiectasis?
Abnormal and permanent dilation and distortion of sub segmental airways, resulting from chronic inflammation damaging the elastic components of the bronchi. Leads to bronchial wall destruction and impaired clearance of secretions
What causes bronchiectasis?
Usually secondary to acquired disease - aspiration, inhalation injury, chronic infections, bronchopneumonia, eosinophilic bronchpneumopathy, chronic bronchitis, possibly allergic bronchopulmonary aspergillosis
Cats - chronic bronchial inflammation
What age and breeds are predisposed to bronchiectasis?
American Cocker Spaniel, Poodles, Siberian Husky and English Springer Spaniels
≥7yo
What are the CT findings of bronchiectasis?
Abnormal bronchial dilation, with lack of tapering and identification of distinct airways within 1cm of pleural surface.
Secondary features - bronchial wall thickening, mucus plugging and peripheral air trapping
What is bronchomalacia?
Weakness of walls of principal/small bronchi, leading to collapse
What types of bronchomalacia are described? What are they associated with?
Static - brachycephalics
Dynamic - tracheal collapse (tracheobronchomalacia)
What is the difference between feline asthma and chronic bronchitis?
CB - secondary to previous insult causing permanent airway damage
Asthma - allergic
What infections can be associated with feline bronchial disease?
Mycoplasma
Aerulostorngylus and Trogostorngylus
What has potential as a biomarker of feline asthma?
BALF endothelin-1
What is the most common cause of spontaneous pneumothorax in cats?
Asthma
How does respiratory distress caused by parenchymal disease most often present?
With increase in both inspiratory and expiratory effort
What is the function of BNP?
Promotes natriuresis, increases GFR, causes vasodilation, antagonises RAAS in animals with increased extracellular fluid volume
What causes BNP to increase?
Volume overload, PHT, cardiac dysfunction
What is a non-cardiorespiratory cause of BNP elevation?
Azotaemia
What is Paragonimus kellicotti? How is it spread? How does it present? How is it diagnosed? How is it treated?
Trematode lung fluke
Eating crayfish
Eosinophilic and neutrophilic inflammation, bullae and cysts
Demonstrating ova in airway lavage fluid or in faeces
Fenbendazole/praziqunatel
What lungworms are reported in dogs and cats?
Paragonimus kellicotti (trematode lung fluke) - D+C
Filaroides - D
Aelurostrongylus abstrusus - C
Crenosoma tuples - D
Oslerus osleri
Eucoleus aerophilus (Capillary aerophila) - D+C
Trogostrongylus - C
Dirofilaria (D+C)
Angiostrongylus vasorum - D
Which parasites infect the pulmonary parenchyma?
Paragonimus kellicotti and filaroides
How is filaroides transmitted? How does it present? How is it diagnosed? How is it treated?
Direct fecal-oral transmission
What contributes to the pathogenicity of bordetella?
Secretion of exotoxins which disrupt the mucociliary escalator
What illness is causes by strep equi subspecies zooepidemicus? Which species are affected?
Haemorrhagic pneumonia. Dogs and cats
What is a ddx for feline pneumonia in midwestern and far western USA?
Yersinim pestis (plague)
What are the natural hosts of yersinia pestis?
Rodents spread by ingestion or transmitted by fleas
How does yersinia pestis present?
Suppurative lymphadenitis
Can develop into septicaemia or secondary pneumonic form
How is yersinia pestis treated?
Aminoglycosides, fluoroquinolone, chloramphenicol and tetracyclines have all been used
What two influenza strains have been implicated in outbreaks in dogs?
H3N8
H3N2
Which breeds are associated with pneumocystis carinii infection?
Miniature dachshunds and CKCS
What immunodeficiency is associated with pneumocytosis?
CKCS - IgG
Miniature Dachsunds and Pomeranians - common variable
Which lung lobe is most effected by aspiration pneumonia?
Right middle, right cranial and caudal portion of left cranial
What is the pathogenesis of non-cardiogenic pulmonary oedema?
Increased vascular permeability following lung injury
Damaged epithelial cells are unable to pump NaCl across the epithelial cell to resolve oedema
How do cardiogenic and non-cardiogenic oedema fluid differ?
NCO fluid higher protein
Why is hypoalbuminaemia not a common cause of pulmonary oedema?
Pulmonary lymphatics are very efficient
What are the possible causes of non-cardiogenic pulmonary oedema?
Neurogenic (seizures, electrocution, head trauma)
Postobstructive
Systemic disease (sepsis, shock, pancreatitis, babesiosis, paraquat poisoning, envenomation, gastric/splenic/mesenteric torsion, parvovirus, uraemia)
Pulmonary injury (aspiration pneumonia, bacterial pneumonia, lung lobe torsion, smoke inhalation)
Miscellaneous (near drowning, altitude, pheochromocytoma)
What is pulmonary lymphomatous granulomatosis? How is it diagnosed?
Lymphoproliferative cancer
Atypical cells infiltrate around and destroy blood vessels
Biopsy needed to diagnose
What is the prognosis for pulmonary lymphomatous granulomatosis?
Durable remission possible
Recurrence of pulmonary involvement or development of lymphoma can occur months to years after treatment
Which lung lobe is most commonly affected by malignant histiocytosis?
Right middle
Do dogs or cats get primary lung neoplasia most often?
Dogs
What is the most common primary lung tumour?
Adenocarcinoma
Which lung lobes are most often affected by solitary nodular tumours (other than histocytic)?
Caudal lung lobes
What gender and breeds are predisposed to eosinophilic pneumonia?
Females
Siberian Husky, Alaskan Malamute, Rottweiler
What respiratory disease in dogs is associated with loud inspiratory crackles?
Idiopathic pulmonary fibrosis
What radiographic finding is a negative prognostic indicator following drowning?
Sand bronchograms
What PaO2:FiO2 ratio is associated with severe respiratory compromise?
<300
What are:
a) Bullae
b) Blebs
c) Pulmonary cysts
a) Air pocket resulting from destruction of alveolar walls and confluence of adjacent alveoli. Not lined with epithelium
b) Accumulations of air escaped from the lung trapped within the visceral pleura. Always found on rung surface
c) Lined with pulmonary epithelium
What are the causes of bullae?
Idiopathic, parasitic, neoplastic, infectious, congenital (bronchopulmonary dysplasia)
What breeds are overrepresented for lung lobe torsion?
Pugs and Afghan Hounds
What are the CXR findings in lung lobe torsion?
Pleural effusion
+/- abnormal bronchus position
Narrowed proximal bronchus
Vesicular gas pattern
Which lung lobe is most commonly affected by torsion?
Left cranial and right middle
What are the inducers of pulmonary vasoconstriction?
Hypoxia
Endothelin-1
Serotonin
What is the stimulus for endothelin-1 release? What are its effects?
Changes in blood flow, vascular stretch, increased thrombin
Smooth muscle growth, collagen synthesis, vascular remodelling
What conditions are associated with increased endothelin-1 concentrations?
Heartworm
Left heart disease
What effects do prostacyclin and thromboxane A2 have on pulmonary artery cells?
Prostacyclin - vasodilator, platelet inhibitor, anti proliferative effects
Thromboxane A2 - vasoconstrictor, platelet activator
How does nitrous oxide cause vasodilation?
Activates cGMP - vasodilation
What test can be useful in ruling out a PTE?
D-dimers
What clinical findings are considered highly suggestive of PHT?
Syncope
Respiratory distress at rest
Activity/exercise terminating in respiratory distress
R-CHF
How is pulmonary artery pressure estimated?
Modified Bernoulli equation
PG = 4xTRV-squared
Estimated RA pressure + PG = PAP
What factors alter TRV?
PAP
PVR
RV function
Pericardial restraint
What is the primary metric used to estimate PAP in dogs?
TRV
How can PHT secondary to left heart disease be diagnosed?
Evidence of PHT
+ documentation of LHD + LA enlargement
What condition could potentially cause PHT secondary to LHD, with an elevated PAWP without LA enlargement?
Acute onset LHD (eg chord tendineae rupture)
Describe the classification system for PHT?
Consensus pg 6
Ddx chylothorax
Idiopathic (>50%)
Cardiac disease
Cranial vena caval thrombus or mass
Heartworm disease
Neoplasia
In dogs, which lung lobes are most commonly affected by bulbous lesions?
Left cranial, right cranial
What clinical signs are associated with mediastinitis?
Tachypnoea, dyspnoea, cough, head/neck oedema, regurgitation
