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What are the most common viral agents involved with PRDC? (3)
porcine reproductive and respiratory syndrome virus (PRRSv), porcine circovirus type II (PCV2), influenza A virus (IAV)
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What bacterial agents are most commonly associated with PRDC? (8)
Mycoplasma hypopneumoniae, pasteurella multocida, Actinbacillus pleuropneumonia (APP), Bordatella bronchispecitica, Strep suis, Haemophilus parasuis, Actinobacillus suis, Salmonella choleraesuis
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Clinical signs of PRDC? (6)
fever, anorexia, lethargy, coughing, gauntness, labored breathing ("thumping")
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Acute outbreak of fever and a barking cough leads you to think of _________.
IAV
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Thin, fuzzy, thumping nursery pigs leads you to think of _________.
PRRSV
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Wasting pigs in finisher with respiratory disease and loose stools leads you to think of _________.
PCV2
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Anteroventral consolidation (bronchopneumonia) is a result of... (5)
Mycoplasma hyo, IAV, Bacterial [P. multocida, Strep suis, Haemophilus parasuis]
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Interstitial pneumonia is a result of... (5)
PRRSV, PCV2, bacterial septicemia (Salmonella cholerasuis, Strep suis), ascarid larval migration
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PRRSV is a(n) __________ virus; therefore, it should be _________.
enveloped; easy to kill
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What makes PRRSV so hard to prevent and treat?
mutates at an unusually rapid rate
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PRRSv is _______ infectious; it is transmitted by... (6)
highly; direct contact, aerosol, fomites (on your boots!), semen from boar studs, needles, +/- biting insects
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Does immunity to one strain of PRRSv protect against other strains?
NOPE
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What is the most significant (dollar-wise) disease in the swine industry?
PRRSv [widespread cause of abortion and respiratory disease]
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________ is an important trigger for clinical PCV2 infection.
PRRSv
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Clinical signs associated with PRRSv infection? (7)
dyspnea, tachypnea, ill-thrift, poor growth, grower/feeder pigs, rarely fatal in adults; subclinical infections common
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PRRSv targets ________ [cell type]; primary sites in acute disease include... (2)
macrophages; lung, lymphoid tissue [chronic--> kidney, spleen, spleen, heart, thymus, lymph nodes, tonsils]
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What gross lesions are seen with PRRSv? (2)
diffuse interstitial pneumonia (red, rubbery, non-collapsing), diffuse lymph node enlargement
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All strains of PRRSv induce __(2)__.
lymphadenopathy and hyperplasia of lymphoid follicles
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How do you diagnose PRRSv? (4)
PCR, virus sequencing (to determine what strain), ELISA, immunohistochemistry
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Are vaccines effective at controlling PRRSv?
No- lack of protection b/w strains
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When trying to control PRRSv, the focus should be on...
stopping PRRSV transmission from sow to pig
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PCV2 causes __________, which is...
porcine circovirus associated diseases (PCVAD); a slew of diseases that may be a result of initial viral infection.
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PCV2 is found in ___________; it does/does not always cause disease when present.
healthy pigs; does not
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How can you attribute disease to PCV2? (3 criteria)
clinical signs (wasting), lymphoid depletion, isolate PCV2 virus
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Lesions associated with PCV2? (4)
interstitial pneumonia, ulcerative bronchiolitis, peribronchiolar inflammation and fibroplasia, granulomatous inflammation in septae
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What tissues need to be addressed/ sent out when diagnosing PCV2? (5)
tonsil, lymph nodes, spleen, peyer's patch (ileum), lung
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Clinical signs of PCV2? (2)
wasting/ ill thrift, marked lymphadenopathy
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What is the focus when trying to control PCV2? (4)
decreasing stress, improving pig comfort (stocking density, minimize regrouping pigs- all in, all out), vaccinate, ID and control concurrent diseases
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Influenza A virus is a(n) _________ virus; it is hard to vaccinate for because... (2)
enveloped; lots of antigenic drift (point mutations) and antigentic shift (genetic reassortment)
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Clinical signs of IAV. (7)
coughing/ sneezing, nasal d/c, fever, lethargy, decreased appetite, ill thrift, abortions
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Why does IAV cause abortions in sow units?
the sow gets a fever--> abortion; does NOT directly attack fetus/repro tract
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Recovery from IAV is _______ if it is a(n) _________ infection.
rapid; uncomplicated
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The 2009 flu pandemic was caused by _______.
H1N1 (IAV)
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After the 2009 flu pandemic, the USDA began a surveillance program to monitor... (4)
trends in virus prevalence, emergence of new subtypes, interspecies transmission events, baseline to develop intervention strategies
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With acute flu in pigs, there is ________ morbidity and ________ mortality; recovery occurs within _________.
high; low; 2-6 days [if uncomplicated]
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With chronic flu in pigs, it is difficult to distinguish from ___________; chronic flu is more common in ___________ operations.
Mycoplasma; continuous flow (not all in, all out)
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IAV is usually seen in pigs __________ of age.
over 12 weeks
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What are gross lesions of IAV?
patchy consolidation in anteroventral lung lobes
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What are antemortem diagnostics for IAV in pigs? (3)
nasal swabs, oral fluids, snout wipes--> PCR, ELISA, serology
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What are post-mortem diagnostic for IAV in pigs? (2 tissues you must send out)
lung tissue and nasal swab- send out
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How do you prevent IAV on pig operations? (2)
prevent new introductions (all in, all out- biosecurity), vaccine gilts as they come in and pre-farrowing [vaccine isn't great...can do without this]
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Infection with Mycoplasma hyo is also known as ____________; characteristics of this bacterium include... (3)
enzootic pneumonia; lacks cell wall, gram-neg, survives up to 27d in wet environment.
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One of the most common and economically important diseases of swine.
Mycoplasma hyo [decreased growth, lower feed efficiency]
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What age animal are usually affected by Mycoplasma hyo?
>6 weeks of age because very long incubation period (21 days)--> stress of weaning aids in establishment of active infection
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Describe the pathogenesis of Mycoplasma hyo infection.
attached to ciliated cells of upper airways--> damage cilia/decrease motility--> impaired mucociliary clearance--> secondary infections
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What are the clinical signs of the acute and chronic phases of infection with Mycoplasma hyo? (acute 3, chronic 3)
- Acute: moderate fever, decreased feed intake, +/- diarrhea
- Chronic: chronic dry hacking cough, increase in severity of cough over time, +/- dyspnea with secondary infection
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Chronic Mycoplasma hyo infection has ________ morbidity and ________ mortality.
high; low
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Describe the gross necropsy findings with Mycoplasma hyo infection.
well-demarcated, tan, anteroventral consolidation
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What is a characteristic finding on histopath of animals infected with Myoplasmal pneumonia?
peribronchiolar lymphoid hyperplasia
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How is Mycoplasma hyo diagnosed ante mortem? (3)
immunohistochemistry, PCR, serology (ELISA)
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Describe Myoplasma hyo control in swine herd. (4)
- All in, All out (AIAO)
- Medicated Early Weaning (MEW)
- Vaccination (these vaccines actually work!)
- Medication for txt/control: Lincomycin, tetracycline, tiamulin, pulmotil
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Both IAV and Mycoplasma hyo have _________ lesions associated with disease; tell them apart by....
anteroventral; patchy AV consolidation (IAV) versus consolidation of entire AV lobe (Mycoplasma)
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What are the 2 primary differentials for hemorrhagic and necrotizing pleuropneumonia?
Actinobacillus pleuropneumonia (APP) and Actinobacillus suis
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How is APP transmitted?
moderately resistant in environment, direct contact, droplets over a short distance [pigs that survive remain carriers]
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What are the clinical signs of acute outbreaks of APP? (6) Signs of chronic infection? (2)
- Acute outbreak: sudden death of finisher hogs, high fever, prostration, dyspnea, bloody d/c, no eating/DRINKING
- Chronic: chronic cough, slow growth
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APP causes __________; many pigs harbor the organism and _________ causes clinical disease.
contagious pleuropneumonia; environmental stresses (temperature fluctuations, etc)
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What lesions are associated with APP? (4)
[dorso-caudal lungs] blood tinged fluid in thorax, bloody froth in airways, fibrinous pleuritis, large areas of hemorrhage
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What are ante mortem tests for APP? (4)
culture followed by serotyping, serology (complement fixation, ELISA, hemolysin neutralization)
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How do you control APP? (6)
ANTIBIOTICS ASAP- Penicillin, Ceftiofur, Tulathromycin, improved ventilation, difference source for pigs in the future, +/- vaccines (not that great)
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Describe Actinbacillus suis in healthy pigs.
resides in tonsils, nostrils, vaginas--> subclinical infection is widespread, clinical infection is sporadic
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What is the most commonly affected group with A. suis infections?
suckling and recently wean pigs (2-4 wks old)--> found dead
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What clinical signs are associated with active A. suis infection in the following groups:
Nursery pigs (6)
Grow/Finish pigs (4)
Adults (4)
- Nursery pigs: sudden death, fever, anorexia, polyserositis, arthritis, pneumonia
- Grow/Finish pigs: sudden death, pneumonia, fever, coughing
- Adults: lethargy, anorexia, reproductive infections in sows, red rhomboid skin lesions
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What diseases must you be sure to rule out when diagnosing A. suis in the following groups:
Nursery pigs (2)
Grow/Finish pigs (1)
Adults (1)
- Nursery pigs: Strep suis, Haemophilus parasuis
- Grow/Finish pigs: APP
- Adults: Erysipelas
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How is definitive determination b/w A. suis and APP currently performed?
culture [CANNOT be reliably differentiated based on gross or microscopic lesions]
-
How do you control A. suis infections? (6)
- Antibiotics ASAP- Ceftiofur and Ampicillin (+/- penicillin and tetracycline)
- Sanitation, ventilation, temperature control, stocking density
-
What bacteria is strictly secondary, ie. is NOT a primary cause of pneumonia?
Pasteurella multocida
-
How do you diagnose P. multocida ante mortem? (2)
culture and sensitivity- FIND PRIMARY CAUSE
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What are etiologies of atrophic rhinitis? (2)
- Bordatella bronchiseptic - atrophic rhinitis [reversible, mild]
- Pasteurella multocida- progressive atrophic rhinitis [permanent turbinate atrophy]
-
What are clinical signs of atrophic rhinitis? (4)
deviated snout, tear staining, sneezing (esp in nursery), bleeding/crusting of nostrils/snout
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Atrophic rhinitis causes _________ morbidity and _________ mortality.
high; low
-
What is the most costly aspect of atrophic rhinitis?
retardation of growth
-
What is the predominant gross lesion associated with atrophic rhinitis?
atrophy of the turbinate bones
-
How is atrophic rhinitis diagnosed? (4)
deviation/shortening of snout, culture, PCR, probes
-
The severity of atrophic rhinitis is influenced by... (4)
air quality, genetics (yorkshires), immunity of dams, weaning age (<14d elliminated transmission)
-
How do you control atrophic rhinitis? (3)
vaccination (esp. of sows), medication (oxytetracycline, ceftiofur), environmental management
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