Flashcards in Respiratory diseases of pigs Deck (85)
What is the gross pathology of swine influenza?
1. conjunctivitis and nasal discharge
2. consolidation of cranial and middle lobes
3. enlarged and edematous bronchial/mediastinal LN
4. blood tinged fibrinous exudate
5. interlobular edema
6. gross lesions similar to mycoplasma hyopneumoniae
What is the distribution of swine influenza in lung pathology?
What is the histopathology of swine influenza?
airways/alveoli filled with exudate
How is swine influenza diagnosed?
1. histopathology (necrotizing bronchiolitis and bronchitis)
2. confirmation via PCR, IHC
Why might a false negative occur with swine influenza?
lesions come and go very quickly
may get false negative >8 days post infection
What kind of antibody is used with SIV IHC?
type A antibody
works in all species
How is diagnosis of SIV done on a population level?
1. serology--serotypes specific or generic
2. PCR--nasal swabs
3. genomic analysis
When is the best time to collect a sample for SIV?
48 hr post exposure (24hr of showing signs)
What are 4 aspects of treatment and control of SIV?
2. antimicrobials (2ndry infection)
3. improve indoor air quality
4. vaccination--commercial vs autogenous
What are the most virulent serotypes of actinobacillus pleuropneumoniae?
What is the epidemiology of actinobacillus pleuropneumoniae?
1. primarily horizontal transmission
2. not likely to transmit between herds
3. short incubation periods (6-12hrs)
Which resp disease is likely to transmit between herds in hog dense areas: SIV or actinobacillus pleuropneumoniae?
Severity of actinobacillus pleuropneumoniae depends on what?
2. exposure dose
3. immune status of herd
4. concurrent dz
Which resp disease has an incubation period of 6-12hrs?
What is the pathogenesis of actinobacillus pleuropneumoniae?
1. colonize tonsils, alveolar epithelium
2. phagocytosed by macrophages
3. produce 4RTX exotoxins
4. inflammatory cytokine production
5. septic shock
6. arteriolar thrombosis and alveolar necrosis
What exotoxins does actinobacillus pleurpneumoniae produce?
4 RTX exotoxins (Apo I, II, III, IV)
What do the exotoxins and the cytokines involved in actinobacillus pleuropneumoniae infection cause?
1. septic shock (peracute death)
2. arteriolar thrombosis and alveolar necrosis
What are the clinical signs of actinobacillus pleuropneumoniae?
1. peracute: cyanosis, foamy bloody nasal discharge, found dead
2. acute: dyspnea, coughing, agonal breathing
3. chronic: chronic pleuritis-->chronic cough; reduced appetite/growth
What is the pathology of peracute and acute actinobacillus pleuropneumoniae?
necrotizing and hemorrhagic pneumoniae
well demarcated, usually CAUDAL LOBES
What is the pathology of chronic actinobacillus pleuropneumoniae
1. chronic pleuritis and adhesions
2. consolidation and necrosis
3. pulmonary abscesses
Why is pleuritis an important feature to look for when looking for actinobacillus pleuropneumoniae
because carcasses going through a scalding tank can look like they have hemorrhagic pneumoniae but they wont have pleuritis
How is actinobacillus pleuropneumoniae diagnosed at the individual level?
1. necrotizing hemorrhagic pneumoniae with focal pleuritis
2. culture and serology
What types of serology is there for actinobacillus pleuropneumoniae?
1. generic ELISA
2. specific for individual serotype
(remember some cross react)
How is actinobacillus pleuropneumoniae controlled?
1. environmental control
2. strategic medication
3. vaccination (serotype specific, autogenous)