What are examples of primary benign neoplasias of the lung that are epithelial origin?
Primary benign: rare
- Papillary adenoma
- Bronchiolar‐alveolar adenoma
What are examples of malignant primary lung neoplasia that are epithelial in origin?
Bronchiolar‐alveolar carcinoma: esp. dogs
Adenocarcinoma: esp. cats
Squamous cell carcinoma: rare in lung
Retroviral pulmonary carcinoma (sheep)
What is ￼￼￼￼￼￼Jaagsiekte sheep retrovirus?
Exists in most sheep raising parts of the world
A significant problem in south Africa
Disputed breed differences in susceptibility
A retrovirus has been identified
What are examples of benign primary neoplasia that are mesenchymal in origin?
- hemangioma → pretty rare, potential because of BV in lungs
What are examples of malignant neoplasia's of the lungs that are mesenchymal in origin?
Osteosarcoma, chondrosarcoma - both rare
Malignant histiocytosis (canine) → Bernese Mtn Dog
Granular cell tumor (equine) → common in horses
Mesothelioma → pleural kind
What do granular cell tumors look like grossly?
- Bulge into bronchial lumen and obstruct airways
- half of lung blocked off → becomes atelectic
Describe the histology of granular cell tumors?
Round cells with eosinophilic cytoplasm
and PAS‐positive granules
What are examples of metastatic tumors?
Uterine carcinoma cow
Sarcoma‐ dogs and cats → HSA, OSA, mast cell tumor
Carcinoma → urinary bladder, thyroid gland, pancreas, intestine
What does pneumothorax result in?
- atelectasis because negative thoracic
pressure cannot be maintained
- something cause negative pressure to change
What should you listen to during the opening of a thorax during a necropsy?
- listen for entry of air → normal
What are causes of pneumothorax?
Trauma‐ bite wound, projectile, hit‐by‐car ****
Rupture of emphysematous bullae
Rupture of abscess or granuloma that
communicates with airway.
Describe the mediastinum in the:
1. Communication between the two pleural cavities
2. No communication between the two pleural cavities → only 1/2 will be affected
3. The partition is very delicate but complete
What is hydrothorax?
- noninflammatory pleural effusion
- clear to yellow (amber) fluid (transudate)
What might cause a hydrothorax?
- increased venous pressure
- lymphatic obstruction
What might be seen microscopically with chronic hydrothorax?
- can cause reactive hyperplasia of
- fibrotic pleura
In what Clinical Dz's is chylothorax seen?
- Feline cardiomyopathy
- right‐sided heart failure
- Obstruction of thoracic duct by thoracic masses → prevent release of lymph into vena cava
What are possible causes of a hemothorax? 6
1. Blood loss into thorax
2. Rupture of blood vessels‐ trauma
3. Inherited coagulopathy
4. Anticoagulant rodenticide → brodifacoum, diphacinone
5. Rupture of lung neoplasm → hemangiosarcoma
6. Aortic ruptures in horse
What is the most common cause of pleuritis?
- infectious agents (usually bacteria)
- most often reach pleura from
blood or from lesions of bronchopneumonia, aspiration pneumonia or lung abscesses
- pyothorax/pleuritis, unilateral
- against wall, see reactive mesothelial cells and fibrin
What kind of infections usually cause bacterial pleuritis?
What condition does it usually occur with?
1. usually mixed
2. primary pneumonia
What is mesothelioma? ****
What structures does it arise from? 2
- neoplasia of the pleura
- from pleura and pericardium
Where do pleural mesothelioma spread from?
What do they cause in the thorax?
- spreads along pleura
- thoracic effiusion
- plaques along pleura, diaphragm
- will often extend to wall thru extension not metastasis
How do neoplasms metastisize to the pleura?
- Transpleural dissemination of carcinomas and sarcomas
- from the lung, chest wall and mediastinum
What is herpesvirus?
Where do they primarily cause disease in most animals?
Where does the virus hide out?
DNA virusesIntranuclear inclusion bodies
At least one for every species
Many of which are primarily respiratory pathogens
like to hide in nerves and come out when stressed → trigeminal
What is the fline respiratory complex?
Secondary bacterial infections
Describe the pathogenesis of feline resp. complex?
Mostly URT → moves to LRT
- viral infection of cells
→ epithelial necrosis/disruption
→ acute inflammation
→ mixed secondary bacterial infection
→ severe infection can extend to LRT
Feline Herpes Virus
- lots of ulceration = nasal planum
- exudate from around eyes
- often have FeLeuk and FIP
What is Cryptococcus neoformans?
- Most common systemic fungal infection in cats
- less common in dogs
- from spores in dirt - unusual to get from necropsy
What pathogens are involved in kennel cough?
1. Bordetella bronchiseptica
2. Parainfluenza type 2
3. Canine Adenovirus‐2
4. Mycoplasmas → s/t cultured
5. CAV‐1, CHV‐1 and CRCoV
What does bordetella bronchiseptica do to respiratory tract?
- Attach to the cilia and causes ciliostasis
What does CAV-2 do to the redo. tract?
Tracheal epithelial necrosis → so bord can get in and set up
What are sources of kennel cough infections?
Off‐lease dog parks Dog shows
What can kennel cough progress to?
What bacteria may be involved?
Streptococcus Escherichia coli Pseudomonas
What effect does CDV (distemper) have on the immune response?
- decreases it
- Down‐regulates cytokines
- Persists in tissues
What kind of pneumonia can CDV cause? ****
- PRIMARY viral pneumonia → broncho‐interstitial
- SECONDARY bacterial pneumonia
- interstitial pneumonia
What conditions can an interstitial pneumonia be accompanied with?
Type II pneumocyte hyperplasia
Intranuclear and intracytoplasmic eosinophilic inclusion bodies
What is Blastomycosis? **NAVLE**
Endemic to Mississippi, Missouri, Ohio river valleys
Soil saprophyte, associated with water
What organs or tissue become involved after inhalation>
Lung and regional lymph nodes usually involved
Describe gross lesions of blastomycois?
What must you rule out?
- Granulomatous pneumonia, usually multiple nodules
- Have to rule out neoplasia
What are the influenze A virus hosts?
humans, swine, horses, birds
H1N1, H1N2, H3N2
What are CS of Influenza in swine?
Poor weight gain
Labored breathing to "thumping"
When do lung lesions resolve?
What is the prognosis of influenza in pigs?
- in 14 -21 days
- self limiting in uncomplicated cases
When did pigs experimentally inoculated begin to show CS?
When did these CS end?
What did CS coincide with?
- Starts: 1‐3 days after infection
- Ends: 4‐8 days after infection
- virus shedding → nasal secretions
What can reduce virus shedding?
48‐72 hours with protective antibodies