Swine Respiratory Disease Flashcards
What are the most common causes of dyspnea and cough in unweaned pigs?
- iron deficiency anemia
- PRRS
- Bordetella bronchiseptica
- bacterial pneumonia - Hemophilus, Pasteurella, Mycoplasma
- Pseudorabies
- Toxoplasmosis
What are the most common causes of respiratory disease is weaned and older pigs?
- bacterial pneumonia
- PRRS
- worms
- swine influenza
- Pseudorabies
- porcine stress syndrome/heat prostration
- Fumonisin
- Circovirus
What causes atrophic rhinitis? What are some early signs? What is seen in chronic cases?
Bordetella + Pasteurella multocida
EARLY - sneezing, mucopurulent discharge, nasal bleeding, stunted growth, staining of medial canthus
CHRONIC - twisted snout
What is seen on necropsy in cases of atrophic rhinitis? How is it diagnosed? Controlled?
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
How do the etiologic agents of atrophic rhinitis cause twisted snouts?
P. multocida and B. bronchiseptica both contain dermonectrotoxins
What is swine influenza? What clinical signs are seen?
rapidly spreading viral disease with incubation of 12-48 hr –> low mortality, short course (2 weeks)
- weakness
- high fevers
- oculonasal discharge
- coughing
How is swine influenza diagnosed?
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
How is porcine reproductive respiratory syndrome (PRRS) transmitted? What clinical signs are associated?
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)
What does PRRS have a predilection for?
intravascular and alveolar pulmonary macrophages
- replicate within and makes them less effective and kills them –> pigs more susceptible to other diseases
What are 4 signs of PRRS in a naive herd?
- reproductive losses and decreased farrowing rate
- early farrowing at 105-112 days
- increased stillborn, mummified and weak piglets
- increased pre-weaning mortality often associated with increased bacterial infection –> scours, greasy pig disease, meningitis
What clinical signs are seen in adults and piglets with PRRS?
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
How is PRRS diagnosed? Controlled?
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)
What causes Mycoplasma pneumonia in swine? What signs are associated? What is seen in chronic cases?
Mycoplasma hyopneumoniae
- low mortality
- chronic persistent non-productive coughing
- poor growth
- normal appetite
thumps –> dyspnea + abdominal breathing
When is Mycoplasma pneumonia most commonly seen?
shortly after weaning
What is seen on necropsy in cases of Mycoplasma pneumonia?
cranioventral pneumonia
- Mycoplasma hyopneumoniae + secondary pathogens
How is Mycoplasma pneumonia treated? What is prognosis like?
common antibiotics are commonly ineffective –> Nuflor, Draxxin
complete recovery limited, chronic cases have poorer prognosis
What serves as the main source of Mycoplasma pneumonia in pig facilities? How is it transmitted?
carriers
long-distance transmission via aerosols
How can Mycoplasma pneumonia be controlled?
- 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
What are 5 parts of porcine respiratory disease complex (PRDC)?
- Mycoplasma hyopneumoniae
- Swine influenza
- PRRS
- Circovirus
- Pasteurella multocida
What are the 2 forms of Pasteurella pneumonia in pigs?
- subacute - coughing, abdominal breathing, emaciation in finisher pigs
- chronic - respiratory signs, fever
How is Pasteurella pneumonia diagnosed? How is it treated?
- gross necropsy
- culture P. multocida from lungs
common antibiotics are often ineffective –> newer antibiotics have better success
What 4 diseases are caused by swine circovirus?
- postweaning multisystemic wasting syndrome (PMWS) - growing pigs
- porcine dermatitis and nephropathy syndrome (PDNS) - sows
- porcine respiratory disease complex (PRDC)
- PCV-2 associated reproductive failure, enteritis, and CNS disease
What 3 criteria are characteristic of postweaning multisystemic wasting syndrome?
- wasting, weight loss, ill thrift, failure to thrive
- microscopic lymphoid depletion or monocyte-macrophage associated inflammation in any organ
- 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
How do pigs present with porcine dermatitis and nephropathy syndrome (PDNS)?
- 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
What is characteristic of PRDC outbreaks?
unresponsive to antimicrobial therapy, resulting in group morality 2-10x higher than normal
What are 3 options for diagnosing PCV2 infection?
- serology - widespread, pigs will frequently be positive in the absence of clinical signs
- microscopic lesion evaluation and IHC stating
- viral isolation - rarely requested or necessary
How is PCV2 infection treated? Prevented?
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
What causes pleuropneumonia in pigs? What necropsy lesion is characteristic?
Actinobacillus pleuropneumoniae
fibrinous pleuritis often seen in the caudordorsal lung fields (diaphragmatic lobes)
What treatment is recommended for pleuropneumonia?
- parenteral antibiotics - PPG, Ceftiofur, TIamulin, Tetracyclines
- vaccination
What causes Glasser’s disease? What pigs are most susceptible?
Haemophilus parasuis - ubiquitous in many herds and may not cause disease
severe disease in naive or stressed pigs
What parts of the body does Glasser’s disease affect? How is it controlled?
- lungs - pleuritis
- joints - arthritis
- intestines - peritonitis
- brain - meningitis
vaccine –> colostral immunity usually enough
What causes Mycoplasmal polyserositis? Where does it most commonly localize?
Mycoplasma hyorhinis
joints and serous body cavities –> lameness is typically prolonged
How does Ascaris suum cause respiratory disease?
- 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)
What 4 clinical signs are associated with Ascaris suum infection? What 2 necropsy lesions are characteristic?
- unthriftiness, poor weight gain
- rough hair coat
- chronic paroxysmal cough
- occasional abdominal breathing - thumping
multifocal hemorrhagic pneumonia + small white scars on the liver (milk liver)
In what 4 ways can Ascaris suum infection be controlled?
- confinement
- deworm if left on dirt
- wash sows to remove eggs prior to moving to sanitized farrowing area
- early weaning of pigs before eggs become infective
What 3 Metastrongylus species infect pigs? What is their lifecycle like?
- M. elongates**
- M. salmi
- 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
Where does Metastrongylus larvae localize? What necropsy lesion is seen?
break into alveoli to localize into the diaphragmatic lung lobes
parasites found in terminal airways when bronchial tree is opened
What are 3 options for lungworm vaccines?
- live irradiated larvae
- oral
- Huskvac
Swine deworming agents:
