Porcine respiratory disease complex

Question 1

What are most common bacterial porcine respiratory disease complexes?

Answer 1

*mycobacteria hyopneumoniae
*B. bronchiseptica
*P. multocida
*A. pleuropneumoniase
*H. parasuis
*S. suis

Question 2

What are the most common viral porcine respiratory disease complexes?

Answer 2

*PRRSV
*SIV
*PRCV
*PRV
*PCV2

Question 3

How can pigs be infected?

Answer 3

*Direct pig to pig contact
*Infected semen
*People - footwear, clothing, hands

Question 4

What are management and enviromental factors to control disease transmission?

Answer 4

*Ventilation
*Overcrowding / stocking density
*mixing of pig age groups
*Biosecurity + Disinfection

Question 5

What are the 3 immunity an animal gets?

Answer 5

*Innate immunity - from conception / in utero
*Passive immunity - MDA
*Adaptive immunity - Cell mediated immunity + humoral immune response

Question 6

When should pregnant sows be vaccinated to PRRSV?

Answer 6

Only vaccinate in had previous exposure to virus as it is a live vaccine so can cause disease

Question 7

What are the most common strains of swine influenza virus SIV in pigs?

Answer 7

*H1 N1
*H1 N2
*H3 N2

Question 8

What is the incubation period of swine influenza virus?

Answer 8

12-48hrs

Question 9

What are symptoms of SIV in piglets?

Answer 9

*It would be unusual to see any signs of swine flu in the sucking pig unless disease entered the herd for the first time.
*Colostrum may prevent infection during the sucking period.
*Coughing.
*Pneumonia.
*Fever

Question 10

What are symptoms of SIV in sows?

Answer 10

*High temperatures which cause abortions.
*Widespread coughing.
*Pneumonia
When the virus first enters the herd two or three animals may be observed sick for the first two days, followed by:
*A rapid explosive outbreak of inappetence and clinically very ill pigs.
*The effects on the reproductive system follow the sudden onset of a rapid
spreading respiratory disease with coughing, pneumonia, fevers and inappetence.
*Acute respiratory distress persists over a period of 7-10 days (depending on the amount of contact between groups of sows).

Question 11

What are causes / contributing factors of swine influenza virus?

Answer 11

*Infected animals including people, pigs and birds.
*Carrier pigs.
*Birds particularly water fowl, are reservoirs of infection.
*Secondary bacterial infections.
*Fluctuating temperatures.
*Stress.
*Wet bedding and floor surfaces.
*Poor nutrition

Question 12

What does porcine circovirus type 2 affect?

Answer 12

Growing pigs
*Repro failure in breeding herds
*Shed in boar semen

Question 13

What is Enzootic pneumonia also known as?

Answer 13

Mycoplasma hyopneumoniae

Question 14

What does M. hyopneumoniae cause?

Answer 14

*Uncomplicated infection on its own + relatively unimportant with mild effects
*But with other infections - App, Hps, Pasteurella, PRRSV + SIV = pneumonia becomes more complex with serious effect on pig

Question 15

How is Enzootic pneumonia diagnosed?

Answer 15

*Post mortem = lungs = atelectasis + lobar discoloration
*Histology of lesions
*Confirm with ELISA, PCR / Culture

Question 16

What are factors that can increase mycoplasma hyopneumoniae disease likelyhood?

Answer 16

*Overcrowding and group sizes in any one environment of more than 200.
*Variable temperatures and poor insulation.
*Houses with poor hygiene and high levels of carbon dioxide and ammonia.
*High dust/bacteria levels in the air.
*Pig movement, stress and mixing.
*A shortage of trough space.
*Housing with a continuous throughput of pigs.
*Other concurrent diseases.
*Poor nutrition.
*Slatted floors and liquid waste

Question 17

What does Bordetella bronchiseptica do?

Answer 17

*Colonizes ciliated epithelium of respiratory tract, resulting in decreased mucociliary apparatus function + pneumonia
*Necrohaemorrhagic pleuropneumonia lesions in young pigs
*Tan firm bronchopneumonia in older pigs
**CRANIOVENTRAL distribution

Question 18

How is Bordetella bronchiseptica diagnosed?

Answer 18

*Isolation of organism from nasal swabs, trachea + lungs

Question 19

Bordetella bronchiseptica on its own is clinically + economically of no consequence, when is it a problem?

Answer 19

*If toxigenic pasteurella present = 2 organisms = severe progressive rhinitis / PAR progressive atrophic rhinitis