resp notes Q and A 3 Flashcards
List two nasal diseases of dogs for which biopsy provides a definitive diagnosis.
Nasal neoplasia, aspergillosis.
Is immunosuppression a risk factor for nasal aspergillosis?
No, immunosuppression predisposes to systemic aspergillosis, but not nasal aspergillosis.
List three predisposing factors for aspiration pneumonia in adult dogs, and two for puppies less than 5 months old.
Adults: anesthesia, neurologic disease, laryngeal disease, megaesophagus, myasthenia gravis, … Puppies: cleft palate, parvoviral enteritis.
List two bacterial pathogens that can cause outbreaks of lung disease. What form of lung disease is expected?
Bordetella bronchiseptica, Streptococcus canis. Bronchopneumonia.
What gross lesions in the lung are expected with heart failure?
Diffuse pulmonary edema and congestion: red, heavy lungs that ooze fluid from the cut surface and have excessive foam in the trachea.
What 2 histologic lesions are characteristic of acute interstitial lung disease (ARDS) in dogs?
Hyaline membranes, alveolar edema.
Briefly explain how a thymoma in an adult dog leads to bronchopneumonia.
Thymoma —> megaesophagus —> regurgitation —> aspiration pneumonia
What is the most inexpensive method of identifying pulmonary emboli at postmortem examination?
Open the pulmonary arteries all the way to the caudal lobes of the lung!
Other than lung, what 3 tissues are most often affected by blastomycosis?
Skin, eye, bone.
What are the two main differential diagnoses for swelling and red discolouration of the right middle lung lobe?
Aspiration pneumonia, lung lobe torsion.
Bastard strangles vs. purpura hemorrhagica: which of these is a consequence of bacteremia, and which is an immune complex-mediated disease?
- Bacteremia —> bastard strangles (visceral abscesses)
- Circulating immune complexes —> purpura hemorrhagica (vasculitis, petechiae, and edema)
What is the gross appearance of guttural pouch mycosis?
A focal plaque of fungal growth, often with necrosis and inflammation of the adjacent tissue, and sometimes, with hemorrhage filling the pouch.
List 2 clinically serious sequelae to mycosis of the guttural pouch in horses.
Hemorrhage from carotid artery, facial nerve paralysis, and others.
What anatomic structure is targeted by the lesions of heaves (severe equine asthma)?
Bronchioles: small airways.
What are 3 mechanisms of airway obstruction in heaves?
Bronchoconstriction. Mucus and neutrophils in the lumen. Edematous swelling of the airway mucosa.
Describe the expected gross lesions of Rhodococcus equi infection of the respiratory tract.
Cranioventral bronchopneumonia, with abscessation or granulomas within the consolidated cranioventral areas of lung.
Why is Rhodococcus pneumonia resistant to many antibiotics that are effective for other forms of pneumonia in horses?
Intracellular location within macrophages. Presence within abscesses. (Drug delivery is poor to both of these locations).
In Rhodococcus infection, what are the two pathogeneses of the lesions in the colonic lymph nodes?
Ingestion of Rhodococcus equi from the environment (dust, soil)
Bacteria are coughed up from lung lesions, swallowed, and reach the intestine.
How does the pathogenesis of fibrinous pleuritis in a feedlot calf differ from that in a racehorse?
- Feedlot calf: hematogenous spread of Histophilus somni results in pleuritis with normal lung tissue.
- Racehorse: the pleuritis is usually secondary to an underlying bacterial pneumonia.
In 2–8-month-old foals with interstitial (bronchointerstitial) pneumonia, what is the gross appearance of the lung?
Diffusely firm, rubbery texture, fails to collapse.
In 2–8-month-old foals with interstitial (bronchointerstitial) pneumonia, what is the common concurrent disease?
Rhodococcus equi pneumonia, which may be either mild or severe.
What are three causes of diffuse interstitial lung disease in neonatal foals?
Hyaline membrane disease, septicemia, Equine herpesvirus-1, meconium aspiration syndrome.
Indicate the distribution and likely cause of bronchopneumonia in a neonatal foal.
Cranioventral distribution.
Streptococcus zooepidemicus & others.
Indicate the distribution and likely cause of interstitial lung disease in a neonatal foal.
- Generalized/diffuse distribution.
- Hyaline membrane disease, septicemia, EHV-1 infection, meconium aspiration.
What is the pathophysiologic basis for dyspnea in a foal with interstitial lung disease? That is, what are two alterations in lung physiology that cause respiratory failure?
Obstruction to gas exchange, reduced lung compliance, reduced functional lung volume.
List two ways that nasal tumours of dogs differ from those of sheep.
Sheep: infectious (retrovirus), expansile (benign).
Dogs: non-infectious, invasive (malignant).
How do the lesions of pneumonic pasteurellosis differ from those of septicemic pasteurellosis in lambs?
- Pneumonic pasteurellosis: cranioventral consolidation of the lung.
- Septicemic pasteurellosis: widespread petechial hemorrhages in lung and other organs.
Which could cause diffuse interstitial pneumonia in animals less than 6 months of age: Maedi visna virus or Caprine arthritis encephalitis virus, or both?
Only Caprine arthritis encephalitis virus affects youngsters. Maedi occurs only in adult sheep.
What is the common lungworm of sheep? Can you see the worms in the centre of the nodules?
Muellerius capillaris; the worms are microscopic, not seen grossly.
What is the key point in the pathogenesis of Pneumocystis infections in foals, pigs, and humans?
The fungus Pneumocystis is thought to only cause disease in immunosuppressed individuals.
How do Mycoplasma hyopneumoniae and PRRS virus predispose to bacterial pneumonia?
- Mycoplasma hyopneumoniae binds to cilia and prevents mucociliary clearance of inhaled bacteria.
- PRRS virus infects macrophages, and suppressed macrophage function accounts for the secondary
pneumonia or septicemia.
What is the cause of fibrinous and necrotizing inflammation of the caudal lung lobe in a grower-finisher pig?
Actinobacillus pneuropneumoniae or Actinobacillus suis.
List 2 specific causes of diffuse interstitial pneumonia in pigs.
PRRS virus, Porcine circovirus-2, septicemia, and others.
What clinical sign is typical with porcine cytomegalovirus infection?
Sneezing and nasal discharge in baby pigs. Also stillbirths, mummies, and perhaps “failure-to-thrive” syndrome.
What are the five locations of exudates, in pigs with polyserositis?
Pleura, pericardium, peritoneum, joints, meninges.
What two bacteria are the most important causes of polyserositis in pigs?
- Streptococcus suis, Glaesserella (Haemophilus) parasuis, Mycoplasma hyorhinis (Mycoplasma hyopneumoniae causes pneumonia; M. hyorhinis causes septicemia)
- Erysipelothrix rhusiopathiae also causes septicemia, but without exudate in body cavities.
Name a reportable disease of pigs that affects the respiratory system.
Pseudorabies
