Module 5: Porcine Respiratory Disease Flashcards by Kianelys Heredia

Terminology:
Mature female, after giving birth

Sow

How well did you know this?

Not at all

Perfectly

Terminology:
Intact male

Boar

How well did you know this?

Not at all

Perfectly

Terminology:
Immature female, before giving birth

Gilt

How well did you know this?

Not at all

Perfectly

Terminology:
Castrated male

Barrow

How well did you know this?

Not at all

Perfectly

Swine Production: Phases
Breeding Herd: Produces weaned pigs
- Gestation: ____(a)____
- Lactation: _____(b)___

(a) 115 days (3 months, 3 weeks, 3 days)
(b) Variable average and range, 16-21 days

How well did you know this?

Not at all

Perfectly

Swine Production: Phases
Finishing Herd: Produces market pigs or replacements
- Nursery: ____(a)____
- Grow-Finish: _____(b)____

(a) 6-a 8 weeks
(b) After nursery until market usually 16 - 18 weeks
Birth to market: 3 + 8 + 18 = 29 weeks = 6 1/2 months

How well did you know this?

Not at all

Perfectly

Porcine Respiratory Disease Complex Basics

How well did you know this?

Not at all

Perfectly

Porcine Respiratory Disease Complex (PRDC) is due to a variable combination of what?

Infectious agents
Environmental stressors
Production/Husbandry problems
Respiratory problems in Growing Pigs

How well did you know this?

Not at all

Perfectly

History and Clinical Signs:
An acute outbreak of fever and barking cough
It might be …

Influenza A virus

How well did you know this?

Not at all

Perfectly

History and Clinical Signs:
Thin, fuzzy, thumping nursery pigs
It might be …

PRRSV

How well did you know this?

Not at all

Perfectly

History and Clinical Signs:
Wasting pigs with respiratory disease and loose stools
It might be …

PCV2

How well did you know this?

Not at all

Perfectly

History and Clinical Signs:
Chronic, sporadic, nonproductive cough
It might be …

M. hyo

How well did you know this?

Not at all

Perfectly

Gross lesions: Anteroventral consolidation (Bronchopneumonia)
Can be most likely:

M. hyo
IAV
Bacteria (P. mult, Strep suis, G. parasuis)

How well did you know this?

Not at all

Perfectly

Gross lesions: Interstitial Pneumonia
Can be most likely:

PRRSV
PCV2
Bacterial septicimia
(S. choleraesuis, Strep suis)
Ascarid larval mgration

How well did you know this?

Not at all

Perfectly

Gross lesions:
If a pig has a ________________ – all rule-outs are in play

bronchointerstitial pneumonia

How well did you know this?

Not at all

Perfectly

The Real Pathogens of Porcine Respiratory Disease Complex

How well did you know this?

Not at all

Perfectly

Family Arteriviridae
- ss (+) RNA, envoloped
Mutates at an unusually rapid rate, even for an RNA virus
Highly infectious
Respiratory disease
Subclinical infections common
Sheedding intermediate

Porcine Reproductive and Respiratory Syndrome virus (PRRSv)

How well did you know this?

Not at all

Perfectly

What is the most common cause of abortion in swine?

PRRSV

How well did you know this?

Not at all

Perfectly

PRRSv infects and destroys _____________ in the lungs

macrophages
- important for removing bacteria and inflammatory debris from the lungs

How well did you know this?

Not at all

Perfectly

What are the main tests for PRRSv?

PCR
Virus sequencing
IHC
ELISA

How well did you know this?

Not at all

Perfectly

Porcine Circovirus Type II (PCV2)

How well did you know this?

Not at all

Perfectly

List the tissues needed to address the multisystemic and variable nature of PCVAD:

Tonsil
Lymph nodes (several from different sites)
Spleen
Ileum (Peyer’s Patches)
Lung
Kidney
Skin
Liver

How well did you know this?

Not at all

Perfectly

(T/F) PCV2 vaccines are available, and they work

True

How well did you know this?

Not at all

Perfectly

Definition:
Is the primary causative agent of porcine circovirus-associated disease (PCVAD). The virus preferentially targets the lymphoid tissues, which leads to lymphoid depletion and immunosuppression in pigs

Porcine Circovirus Type II

How well did you know this?

Not at all

Perfectly

Influenza A Virus (IAV)

- Enveloped Virus - *(-) Stranded RNA Virus* - Antigenic *Drift* - *minor* antigenic changes over time due to point mutations - Antigenic *Shift* - *Major* antigenic changes due to genomic reassortment

Influenza A Virus - H1N1: Classical Swine Influenza - High Morbidity, Low Mortality

Influenza: Growing Pigs - Sudden onset, high % affected, low mortality - "Thumping", "barling" cough, lethargy, fever - Rapid recovery in 2-6 days if uncomplicated

Acute Flu

Influenza: Growing Pigs - *Common in populations* with widely varying passive antibody levels - Common in continuous-flow multiple-barn sites - Difficult to distinguish from mycoplasma pneumonia

Chronic Flu

- Classically seen in pigs over 12 weeks of age - Passive antibody persists for 10-16 weeks - Nursery pig IAV problems - active infection in the breeding herd - focus control on breeding herd immunization

Influenza: Growing pigs

(T/F) It is possible to identify IAV in the fetus

False, it is *extremely rare* to identify IAV in the fetus

Gross lesion: Typically causes *patchy* anteroventral consolidation

Influenza A Virus (IAV)

Influenza: Diagnosis List the Antemortem Diagnostics:

- Nasal swabs, oral fluids, snout wipes - PCR, Antigen capture ELISA, Virus Isolation - Serology - Specific tests for different subtypes

Influenza: Diagnosis List the Post mortem Diagnostics:

- Lung tissue and nasal swabs

What is the treatment for IAV?

- *Supportive care* - NSAIDs - Electrolytes - *Control secondary bacterial infections* - Antibiotics

Mycoplasma hyopneumoniae (MPH)

Mycoplasma Pneumonia of swine is also known as ...

Enzootic Pneumonia

Characteristics - Lacks a rigid cell wall - *Gram-negative* - don't treat with penicillin - Very small organism Survival in the enviroment - 17 days in water at 35-45 F - Inactivated in 48 hours by drying on cloth

Mycoplasma hyopneumoniae

What is one of the most common and economically important diseases of swine?

Mycoplasma hyopneumoniae (M. hyo) - infected pigs grow 12% slower and have poorer feed efficiency - Losses compounded when with co-infections

Why are clinical signs of M. hyo rare in pigs <6 weeks old?

Because of the long incubation time, the infection can occur at any age but 3-10 weeks most common

Describe the Pathogenesis of Mycoplasma:

- Mycoplasma attach to *ciliated cells* in the air passages of the respiratory tract and multiply - loss of cilia and decreased motility -> impaired clearance mechanism

Clinical signs of Mycoplasma hyopneumoniae infections What is the most significant thing about the *acute* form?

It precedes the *chronic form* Acute: - infection in 3-10 week-old pigs - Moderate fever, decreased feed intake, a short period of diarrhea

Clinical signs of Mycoplasma hyopneumoniae infections Describe the chronic form:

- Onset of clinical signs 10-21 days post-infection - chronic, sporadic, dry, hacking, non-productive cough - cough gets more pronounced - Dyspnea is rare unless the secondary infection is present - High morbidity, low mortality - Uneven growth among pen-mates - Decreased feed efficiency - up to 15%

Gross lesion: *Well-demarcated*, dark-colored, anteroventral consolidation

Mycoplasmal pneumonia - *Histopathology*: Peribronchiolar lymphoid hyperplasia characteristic of mycoplasmal pneumonia

List M. hyo diagnosis:

- FA or IHC - detect colonization by PCR - Serology: CF and ELISA

List M. hyo control:

- *Several good M. hyo vaccines on the market* - MEW (12-15 days) - AIAO pig flow

Both IAV and M. hyo are *anteroventral, airway-associated disease* how do you differentiate them?

- Patchy AV consolidation -- more likely to be IAV - Consolidation of entire AV lobe -- more likely to be M. hyo

Pasteurella multocida

What is *NOT* a primary cause of pneumonia?

Pasturella multocida Pneumonia - Little known about the pathogenesis - Diagnosis: - Culture and sensitivity - *Sort out primary causes*

Actinobacillus pleuropneumonia (APP) and Actinobacillus suis

List the two primary differentials for Hemorrhagic and Necrotizing Pleuropneumonia:

- Actinobacillus Pleuropneumonia (APP) - Actinobacillus suis (A. suis) *Both can cause acute death in grow/finish pigs*

- *Gram-negative coccobacillary rod* - Infects *only swine* - At least *15* recognized serotypes - *Moderately resistant to enviroment*

Actinobacillus pleuropneumoniae - pigs that survive often remain carriers - spread by direct contact and droplets over a short distance - poor husbandry & stress promote the disease

- Acute Outbreaks: - *"Sudden death"* - especially in finisher hogs - Prostration, high fever, anorexia - Sometimes a shallow non-productive cough (not an airway irritant) - Dyspnea with open-mouth breathing - *Bloody discharge from nose and mouth* - Mortality can reach 10% in one day - Pigs quit eating AND drinking - Chronic Infections: - Chronic cough - Slow growth These are clinical signs for:

Actinobacillus pleuropneumonia - *contagious* - transmission by close contact and short-distance aerosols - Many pigs harbor organisms in the upper airways

Gross lesions: - Blood-tinged fluid in the thorax - Bloody froth in the airways - Confined to the thorax

Actinobacillus pleuropneumoniae (APP) - "black cigars"

What is the treatment for Actinobacillus pleuropneumoniae (APP)?

- *ANTIBIOTICS* asap - Ventilation - Vaccination - Different sources of pigs

- *Gram-negative*, non-motile, non-encapsulated, very hemolytic, aerobic coccobacillus - Grows well on *blood agar and MacConkey* - Multiple serotypes have been identified

Actinobacillus suis - Age-related syndromes are recognized - no commercially available vaccines

Where does A. suis reside?

In tonsils & nostrils of healthy pigs of any age and the vaginas of healthy sows

A. suis vs. APP Currently, if a pig has a hemorrhagic and necrotizing pleuropneumonia, the lesion is slightly more likely to be caused by ____(a)______ than _____(b)_______

(a) A. suis (b) APP *Treat like APP, hope is A. suis*

(T/F) A. suis and APP can be reliably differentiated based on gross or microscopic lesions

False

Atrophic Rhinitis

"Two Pathogen Party" - *Bordetella bronchiseptica* - *Pasteurella multocida* (second)

Atrophic Rhinitis - Morbidity: can be high - Mortality: negligible - Retardation of growth - the most costly aspect of AR - Loss of turbinate function - may predispose affected pigs to pneumonia

List the clinical signs of *Atrophic Rhinitis*:

- Deviated snout: sideways or pushed up - Tear staining at medial canthus - sneezing -- beginning in nursery - Bleeding from nostrils and crusting of the snout

List diagnosis of Atrophic Rhinitis:

- Standard culture -- not definitive as both PM and BB are common isolates - PCR - used to detect toxin gene in Pasteurella multocida - Probed to detect the toxin-producing genes of both PM and BB

List prevention and control for AR:

Usually requires a combination of actions involving: - Vaccination - Medication - Enviroment - Management

(T/F) The contribution od P. multocida to pneumonia is usually secondary to other infectious diseases or environmental factors that impair pulmonary function

True