Respiratory diseases - pigs Flashcards
Outline the causes of pig respiratory disease
- PCV2 - endemic (>90% farms), immunosuppressive
- PRRS - common on pig farms, immunosuppressive
- Swine Influenza strains - many circulating, new strains in future
Mycoplasma hyopneumoniae: Cs Dx Control Tx
- CLINICAL SIGNS: chronic cough, FCR, variance in growth
- DX: lung lesions, abbattoir, PCR, culture (difficult)
- CONTROL: biosecurity, vaccination, medication
- TX: ABs but not penicillin, depopulation
Actinobacillus pleuropneumoniae Cs Dx Control Tx
- CLINICAL SINGS: acute, cough, dyspnoea, death
- DX: lesions, culture
- CONTROL: biosecurity, vaccination (strains)
- TX: ABs (animals may be very sick)
Pasteurella CS Dx Control Tx
- CLINICAL SIGNS - acute, sudden death or part of PRDC
- DX: culture, lesions
- CONTROL, vaccination?
- TX. none
Haemophilus parasuis CS Dx Control Tx
- CLINICAL SIGNS: polyserositis,
- DX: lesions, culture (difficult)
- CONTROL: ABs, vaccination
- TX: ABs
Aujesky's disease = NOTIFIABLE CS Dx Control Tx
- CLINICAL SIGNS: age dependent, respiratory signs in weaners
- DX: rhinitis, URT, dead end host
- CONTROL: Notifiable
- TX: none
List some less common respiratory diseases of pigs - 8
- Mycoplasma hyopneumoniae
- Actinobacillus pleuropneumoniae
- Pasteurella
- Haemophilus parasuis
- Aujesky’s diease
- Iron deficiency anaemia
- Vitamin E deficiency
- Erysipelas
When might you see vitamin E deficiency in pigs?
When fed rancid food (stored in sunlight), precipitates when there is unusual movement/stress of the pigs (moving pens, vaccination)
When might you see erysipelas infection?
- soil borne organisms
- vaccine good but comes in large vial sizes which makes it expensive for small holders
What factors can cause pig respiratory problems? 4
- Environment (air quality and stocking density)
- Management (stress)
- Breed and age
- Pathogen exposure
What changes at weaning may precipitate development of a respiratory problem? 6
- Moved pens
- Mixed with others/larger groups
- Change of feed
- No mother
- Routine treatments
- Early weaning - can help, can leave a vulnerable population
Name 3 causes of neonatal respiratory disease
- Actinobacillus suis
- Bordetella bronchisepticum
- Progressive atrophic rhinitis
Name 6 causes of respiratory disease in pre-weaned pigs
- Progressive atrophic rhinitis
- Bordetella bronchisepticum
- Inclusion body rhinitis (pig CMV)
- Enzootic pneumonia (Mycoplasma sp)
- PRRSV (reproductive and respiratory syndrome virus).
- Glassers disease (Haemophilus parasuis).
What might cause respiratory disease in weaners, growers and finishers? 10
- Bordetella bronchiseptica
- Glassers disease
- Actinobacillus pleuropneumonia
- Pasteurella multocida
- Mycoplasma hyopneumonia (EP) / hyorrhinis
- PRRSV
- Porcine respiratory coronavirus (PRCV)
- Influenza
- PMWS?/PCVAD
- (Aujeszky’s disease (pig herpesvirus 1))
Name 6 significant respiratory diseases in non-immune adult pigs
- Glassers disease
- Actinobacillus pleuropneumoniae
- Pasteurellosis
- Enzootic pneumonia
- PRRSV
- Influenza
What is PMWS?
an old name for PCV-2 related disease
What is the commonest cause of sudden death in adult pigs?
Pasteurellosis (aslo common are influenza and PRRSV)
PME appearance of Pasteurellosis
- consolidation of lung next to spongy lung
- typically consolidation in caudal lung lobes (90% O2 exchange occurs here) so pigs present with dyspnoea
What does Mycoplasma damage?
mucociliary clearance
Define FCE
Feed conversion efficiency
What respiratory problems do bacteria cause?
URT problems and pneumonia
What does Mycoplasma hyopneumoniae cause?
‘enzootic pneumonia’ in pigs. Great economic importance as 30-80% pigs have lesions at slaughter
How is M.hyopneumoniae spread? 2
- carrier animals
- aerosol (2 miles)
Dx - M. hyopneumoniae - 5
- CS
- lung lesions at slaughter
- culture/PCR
- histology
- serology
What is APP?
Actinobacillus pleuropneumoniae
Outline A.pleuropneumoniae infection
- 12 capsular subtypes but cross reactions occur
- explosive outbreaks of pneumonia
- high morbidity and mortality
- seroconversion with few CS
- infarcts known as ‘gunshot wounds’. Lesions can occur very quickly
APP - clinical signs
- acute fatal resp disease
- fibrinous pleuritis
- firm lung infarcts (lesions largely produced by the toxins)
APP - diagnosis - 4
- CS
- Culture, PCR
- Lung lesions
- Serology
Epidemiology - APP - 4
- Direct contact
- Movement
- Survives in water /mucous
- Serotypes vary with country (2,8,3,6.7 in UK)
What causes atrophic rhinitis?
Toxigenic Pasteurella multocida in association with Bordatella bronchiseptica
Pathogenicity - Atrophic rhinitics
- Colonisation of nasal mucosa by BS with production of cytotoxin
- PM damages osteoblasts and enhances osteoclast activity –> turbinate damage
Where is atrophic rhinitis prevalent currently?
Scotland
How is atrophic rhinitis scored?
Score 1-5 (5 most severe)
What causes Glasser’s disease?
Haemophilus parasuis
Causes polyserositis
What causes Aujeszky’s disease?
Swine herpesvirus type 1 (SHV1)
- Notifiable and not present in UK (present in NI)
Outline the clinical presentation of Aujeszky’s disease.
AGE AND STRAIN SPECIFIC:
- can cause necrotic rhinitis
- < 4weeks: neuro, mortality <15%
- ADULT: few clinical signs, abortion adn mummification, URT coughing, rare neurological signs
What happens if Aujeszky’s disease is detected?
Slaughter policy in UK.
Targeted vaccination in NI, Ireland and Spain.
Other than pigs, what might die of Aujeszky’s disease?
Cats because they are a dead end host.
What is SIV?
Swine Influenza Virus (similar CS to humans)
CS - SIV
Similar to humans
- pyrexia
- lethargy
- prostrate
- skin erythema
- anorexia
- severe cough and sneeze
- dyspnoea
- conjunctivitis
- recover equally rapidly
- abortion
SIV - diagnosis
- CS
- Serology
- Virus isolation
- Lung lesions (clear demarcation of lesions in cranial and middle lobes, interstitial pneumonia, fibrinous lesions with consolidation of the whole lung)
What is PRRS virus?
An Arterivirus
ssRNA
High mutation rate (new strains possible even in vaccinated herds)
Pathogenesis - PRRS
Virus replicates in and destroys macrophages and endothelial cells –> vasculitis.
CS - PRRS
- weaned pigs
- tachypnoea
- thumping
- eyelid oedema
- conjunctivitis
- respiratory (acute outbreak)
- abortion
- stillbirth
PRRS - diagnosis - 4
- CS
- gross pathology (moderate to severe interstitial pneumonia)
- virus isolation
- serology
Control methods - PRRS - 4
VACCINATION:
•MLV (avoid in pregnant)
•Killed (breeders)
• Use in breeders and growers. Before breeding.
STABILISE INFECTION:
• Expose gilts / vaccinate prior to breeding.
• Stream grower pigs in separate airspaces.
ERADICATION
• Stabilise sow/gilt infection and then depopulate all exc sows. Wean off-site to rest buildings for period.
DEPOP-REPOP
• Infection transmits up to 3km
• Purchase uninfected stock and quarantine / test at isolation.
• Purchase uninfected semen.
What is PMWS associated with?
- PCV-2.
- Immunosuppressive
- 90% UK pigs seropositive
- Involved in many disease syndromes
PMWS - PME findings
- pneumonia
- fibrin
- pericarditis
- little normal tissues
- abscess
- interlobular oedema
Define PRCV
Porcine Respiratory Coronavirus
CS - PRCV
COUGH - in gowers and finishers (endemic), across all age groups (epizootic)
- NOT USUALLY A SIGNIFICANT PROBLEM but contributes to multifactorial pneumonia, indicates biosecurity issue
Define PEDV
Porcine Epidemic Diarrhoea Virus (major worry in the pig industry currently)
Name 2 respiratory parasites in pigs
- Metastrongylus (earthworm is IH)
- Ascaris suum (larval migration through lungs)
What are the most important aspects of control, prevention and eradication of porcine respiratory diseases?
- biosecurity
- medication
- vaccination
- early weaning
- depop-repop
- quarantine
By what routes can drugs be given to pigs?
- in face of an outbreak
- routine/pulse
- in feed/water
- individual animal
Outline vaccination for porcine respiratory disease
- dams to confer immunity to young pigs (AR)
- young/weaner pigs (M.hyo)
- in quarantine and before entry to the herd
Outline full depopulation
- remove all pigs excluding lactating sows (medicate these)
- wean to offsite location for 12 week period
- rest and disinfect weaner and grower accomodation
What might you see in iron deficiency anaemia?
young pigs, pale, high RR, fail to maintain body temperature, thin watery blood.
What disease do UK pig farmers currently worry about?
ASF (currently in Poland and heading west, last UK outbreak was 2000, spread by contaminated pork products).
What heart condition does vitamin E deficiency cause in pigs?
Mulberry heart (pinpricks of lines? laid down outside of the heart)
What heart condition does erysipelas cause in pigs?
bacterial endocarditis
What are the 2 commonest vaccines on UK pig farms?
Mycoplasma and PCV2
Define total depopulation
Get rid of whole herd in an effort to control/stop disease. This is not possible if there is another pig farm within a 5 mile radius.
List the fat soluble vitamins
ADEK. N.b. pigs have quite a high vitamin E need.
What lesions does erysipelas cause acutely
diamond lesion. Seed to heart causing endocardutus.
