Flashcards in Porcine circovirus associated disease Deck (23)
What is PCVAD?
a group of diseases associated with common underlying viral infection PCV2
To diagnose PCVAD, what must be present?
1. clinical signs
2. hallmark microscopic lesions
3. virus in lesion
Why is PCV2 necessary but insufficient cause to dx PCVAD?
because it is ubuiquitous and most pigs become infected with PCV2, some get dz
what are the two clusters of PCV2?
2a and 2b
2a is in the vaccines
What is the epidemiology of PCV2?
1. ubiquitous, stable, resistant
2. infection may be asymptomatic/subclinical
3. overt disease requires co-factors that enhanced PCV2 replication
What are factors that influence the expression of PCV2>
1. poor managemnet
3. mycoplasma hyopneumniae
8. vaccine status
What type of herd presentations of PCV2 are there?
What are the clinical signs of post-weaning multisystemic wasting syndrome?
1. elevated mortality
2. weight lost, wasting
3. pallor (jaundice)
4. diarrhea (grow, finish)
What are the clinical signs of reproductive presentation of PCV2?
1. elevated mummies, still births, abortions etc
2. often start-up herds without vaccination program
3. still birthws with non-suppurative necrotizing myocarditis with PCV2 antigen!
What is the lesion seen in still births caused by PCV2?
non-suppurative necrotizing myocarditis with PCV2 antigen
What stages of gestation are affected by PCV2>
What stage of gestation does PCV2 affect? PRRS? parvovirus?
1. multiple (
What is the pathogenesis of PCVAD?
1. predilection for dendritic cells and macrophages
2. these cells accumulate PCV2, viral persistence
3. modified DC function, impaired innate pathogen recognition signals and antigen presentation
4. lymphoid depletion
6. seroconversion (some pigs remain persistenly viremic and asymptomatic)
What is the role of immune stimulation in PCVAD-PMWS?
a near simultaneous immune stimulation is associated with higher PCV2 replication in tissues, which is positively correlated with severity of disease
Why would you be concnerend with using vaccines (especially mycoplasma vaccines) in nursery animals with PCV2 viremia?
ecuase immune stimulation while the pig is infected can restul in massive replication of PCV in tissue
What is the pathology of PCV2?
1. lymphoid tissues: lymphadenopathy--depletion and granulomatous inflam, thymic atrophy
2. liver: hepatocyte necrosis, icterus
3. lung: interstitial pneumonia
4. kidney: intersitial nephritis (white foci)
5. GIT: granulomatous enteritis
What two diseases cause white foci in liver?
What is the most appropriate tool for defninitive diagnosis of PCV2?
How is definitive diagnosis achieve with PCV2?
Multiple tissues from multiple pigs
Must fulfill case deinition
1. clinical signs
2. histologic lesions: lymphoid depletion, granulomatous inflam
3. virus in lesions (IHC)
What is treatment of PCV2?
mass medication/anti-inflammatory for secondary disase
What is control/prevention of PCV2?
1. control concurrent dz
2. reduce immune stimulation
3. implement good production practices
What are the different PCV2 vaccines available?
1. ingelvac/circoFLEX is capsid protein for piglets
2. PCV2-1 chimera for piglets
3. PCV2 capsid protein piglets
4. inactivated PCV2: sows, piglets