Swine Respiratory Disease

Question 1

What are the most common causes of dyspnea and cough in unweaned pigs?

Answer 1

• iron deficiency anemia
• PRRS
• Bordetella bronchiseptica
• bacterial pneumonia - Hemophilus, Pasteurella, Mycoplasma
• Pseudorabies
• Toxoplasmosis

Question 2

What are the most common causes of respiratory disease is weaned and older pigs?

Answer 2

• bacterial pneumonia
• PRRS
• worms
• swine influenza
• Pseudorabies
• porcine stress syndrome/heat prostration
• Fumonisin
• Circovirus

Question 3

What causes atrophic rhinitis? What are some early signs? What is seen in chronic cases?

Answer 3

Bordetella + Pasteurella multocida

EARLY - sneezing, mucopurulent discharge, nasal bleeding, stunted growth, staining of medial canthus

CHRONIC - twisted snout

Question 4

What is seen on necropsy in cases of atrophic rhinitis? How is it diagnosed? Controlled?

Answer 4

nasal turbinate exam by the 2nd premolar shows a deviated septum

culture of tonsillary swabs - positive for Bordetella bronchiseptica or Pasteurella multocida, but they are normal flora

vaccinate + feed-grade antibiotics

Question 5

How do the etiologic agents of atrophic rhinitis cause twisted snouts?

Answer 5

P. multocida and B. bronchiseptica both contain dermonectrotoxins

Question 6

What is swine influenza? What clinical signs are seen?

Answer 6

rapidly spreading viral disease with incubation of 12-48 hr –> low mortality, short course (2 weeks)

• weakness
• high fevers
• oculonasal discharge
• coughing

Question 7

How is swine influenza diagnosed?

Answer 7

reliably diagnosed on clinical grounds because there are no other diseases that are so dramatic in their onset and clinical effects

• CONFIRMATION - blood samples taken at time of onset and 2-3 weeks later show rising levels of antibodies + nasal/throat swabs

Question 8

How is porcine reproductive respiratory syndrome (PRRS) transmitted? What clinical signs are associated?

Answer 8

respiratory and reproductive (semen) fluids

• SOWS - abortion at any stage of pregnancy, illness/death uncommon
• NEONATES/YOUNG - infected in utero or shortly after birth –> weak, depression, respiratory distress, cyanosis, high mortality (peak at 4-10 weeks)

Question 9

What does PRRS have a predilection for?

Answer 9

intravascular and alveolar pulmonary macrophages

• replicate within and makes them less effective and kills them –> pigs more susceptible to other diseases

Question 10

What are 4 signs of PRRS in a naive herd?

Answer 10

1. reproductive losses and decreased farrowing rate
2. early farrowing at 105-112 days
3. increased stillborn, mummified and weak piglets
4. increased pre-weaning mortality often associated with increased bacterial infection –> scours, greasy pig disease, meningitis

Question 11

What clinical signs are seen in adults and piglets with PRRS?

Answer 11

ADULTS - reproductive signs, mild fever, anorexia, massive abortions

PIGLETS THRU FINISHING - respiratory disease, unthrifty, failure to thrive, increased secondary bacterial infections, increased mortality, decreased appetite, fever, rough haircoat, pneumonia, atrophic rhinitis

Question 12

How is PRRS diagnosed? Controlled?

Answer 12

demonstrating of virus + serological profiling to determine herd status

• stabilize infection with immunity - MLV vaccination, killed not recommended (intentional whole herd, allow 60 days between exposure and breeding)
• quarantine
• segregate rearing of offspring (all in, all out)

Question 13

What causes Mycoplasma pneumonia in swine? What signs are associated? What is seen in chronic cases?

Answer 13

Mycoplasma hyopneumoniae

• low mortality
• chronic persistent non-productive coughing
• poor growth
• normal appetite

thumps –> dyspnea + abdominal breathing

Question 14

When is Mycoplasma pneumonia most commonly seen?

Answer 14

shortly after weaning

Question 15

What is seen on necropsy in cases of Mycoplasma pneumonia?

Answer 15

cranioventral pneumonia

• Mycoplasma hyopneumoniae + secondary pathogens

Question 16

How is Mycoplasma pneumonia treated? What is prognosis like?

Answer 16

common antibiotics are commonly ineffective –> Nuflor, Draxxin

complete recovery limited, chronic cases have poorer prognosis

Question 17

What serves as the main source of Mycoplasma pneumonia in pig facilities? How is it transmitted?

Answer 17

carriers

long-distance transmission via aerosols

Question 18

How can Mycoplasma pneumonia be controlled?

Answer 18

• antibiotics at weaning - tetracycline
• vaccines - reduce lung lesions and improve growth (sows twice before farrowing, piglets at 6-8 weeks and repeated within 2-3 weeks)
• control dust and noxious gases

Question 19

What are 5 parts of porcine respiratory disease complex (PRDC)?

Answer 19

1. Mycoplasma hyopneumoniae
2. Swine influenza
3. PRRS
4. Circovirus
5. Pasteurella multocida

Question 20

What are the 2 forms of Pasteurella pneumonia in pigs?

Answer 20

1. subacute - coughing, abdominal breathing, emaciation in finisher pigs
2. chronic - respiratory signs, fever

Question 21

How is Pasteurella pneumonia diagnosed? How is it treated?

Answer 21

• gross necropsy
• culture P. multocida from lungs

common antibiotics are often ineffective –> newer antibiotics have better success

Question 22

What 4 diseases are caused by swine circovirus?

Answer 22

1. postweaning multisystemic wasting syndrome (PMWS) - growing pigs
2. porcine dermatitis and nephropathy syndrome (PDNS) - sows
3. porcine respiratory disease complex (PRDC)
4. PCV-2 associated reproductive failure, enteritis, and CNS disease

Question 23

What 3 criteria are characteristic of postweaning multisystemic wasting syndrome?

Answer 23

1. wasting, weight loss, ill thrift, failure to thrive
2. microscopic lymphoid depletion or monocyte-macrophage associated inflammation in any organ
3. detection of PCV2 in affected tissues

majority of swine farms are seropositive, but only a small percent show signs –> common in nursery-age or finisher pigs

Question 24

How do pigs present with porcine dermatitis and nephropathy syndrome (PDNS)?

Answer 24

• unalert, non-feverish
• numerous dime-sized, ulcerative, raised lesions on skin –> flank, rear legs, belly –> can coalesce and become crusty and black
• necropsy - enlarged, pale, pinpoint hemorrhage on kidneys

PCV2 +/- Pasteurella multocida

Question 25

What is characteristic of PRDC outbreaks?

Answer 25

unresponsive to antimicrobial therapy, resulting in group morality 2-10x higher than normal

Question 26

What are 3 options for diagnosing PCV2 infection?

Answer 26

1. serology - widespread, pigs will frequently be positive in the absence of clinical signs 2. microscopic lesion evaluation and IHC stating 3. viral isolation - rarely requested or necessary

Question 27

How is PCV2 infection treated? Prevented?

Answer 27

antibiotic therapy for secondary bacterial infection - vaccine - reduces severity and incidence - biosecurity - quarantine new arrivals, minimize visitor traffic, rodent/insect/bird control, shower-in shower-out procedures - production - *ensure adequate intake of colostrum*, minimize cross-fostering, reduce group size, all-in all-out - environment - good ventilation, removal of gas and humidity, appropriate temperature - control of other farm pathogens

Question 28

What causes pleuropneumonia in pigs? What necropsy lesion is characteristic?

Answer 28

Actinobacillus pleuropneumoniae fibrinous pleuritis often seen in the caudordorsal lung fields (diaphragmatic lobes)

Question 29

What treatment is recommended for pleuropneumonia?

Answer 29

- parenteral antibiotics - PPG, Ceftiofur, TIamulin, Tetracyclines - vaccination

Question 30

What causes Glasser's disease? What pigs are most susceptible?

Answer 30

Haemophilus parasuis - ubiquitous in many herds and may not cause disease severe disease in naive or stressed pigs

Question 31

What parts of the body does Glasser's disease affect? How is it controlled?

Answer 31

- lungs - pleuritis - joints - arthritis - intestines - peritonitis - brain - meningitis vaccine --> colostral immunity usually enough

Question 32

What causes Mycoplasmal polyserositis? Where does it most commonly localize?

Answer 32

Mycoplasma hyorhinis joints and serous body cavities --> lameness is typically prolonged

Question 33

How does Ascaris suum cause respiratory disease?

Answer 33

- eggs are ingested and hatch in the intestines - larvae bass in the blood to the liver --> lungs (eggs survive 15 years and require 2-3 weeks in the environment before they are infective)

Question 34

What 4 clinical signs are associated with Ascaris suum infection? What 2 necropsy lesions are characteristic?

Answer 34

1. unthriftiness, poor weight gain 2. rough hair coat 3. chronic paroxysmal cough 4. occasional abdominal breathing - thumping multifocal hemorrhagic pneumonia + small white scars on the liver (milk liver)

Question 35

In what 4 ways can Ascaris suum infection be controlled?

Answer 35

1. confinement 2. deworm if left on dirt 3. wash sows to remove eggs prior to moving to sanitized farrowing area 4. early weaning of pigs before eggs become infective

Question 36

What 3 Metastrongylus species infect pigs? What is their lifecycle like?

Answer 36

1. M. elongates** 2. M. salmi 3. M. pudendotectus larvae hatch in feces --> larvae are eated by earthworms --> larvae mature in earthworms to infective L3 --> pig eats earthworm, allowing larvae to penetrate intestine and migrate to the lungs via blood/lymphatics - migration causes a great deal of inflammation, predisposes to secondary infection, and physically obstructs small airways

Question 37

Where does Metastrongylus larvae localize? What necropsy lesion is seen?

Answer 37

break into alveoli to localize into the diaphragmatic lung lobes parasites found in terminal airways when bronchial tree is opened

Question 38

What are 3 options for lungworm vaccines?

Answer 38

1. live irradiated larvae 2. oral 3. Huskvac

Question 39

Swine deworming agents:

Answer 39