Lecture 12/13 3/21/24 Flashcards
How long is pig gestation?
114 days (3 mo., 3 weeks, 3 days)
When are gilts considered mature and able to be bred?
170-220 days of age
What is farrowing?
birth to weaning, 21 days
At what age are pigs considered finished?
115-120 days
What are the general characteristics of swine influenza?
-enveloped, single stranded, neg-sense SEGMENTED RNA genome
-capable of rapid evolution
-subtypes H1N1, H1N2, H3N2
-zoonotic
What are the characteristics of the 2009 H1N1 pandemic?
-swine-origin reassortant virus
-high genetic diversity of circulating strains
-high morbidity, low mortality
-enzootic in densely populated pig production areas
-component of porcine resp. disease complex
What is the pathogenesis of swine influenza?
-transmitted through droplets/aerosol, direct contact, fomite contamination
-no viremia; secreted in resp. secretions
-shedding begins 1-2 days post infection and lasts up to 10 days
-incubation period of about 1-3 days
-all ages of pig susceptible
What are the clinical signs of swine influenza?
-fever over 104F
-lethargy
-anorexia
-loss of body condition/weight loss
-coughing
-nasal discharge
-tachypnea
-dyspnea
-sneezing
-repro failure
How is swine influenza diagnosed?
-antibody response (HAI/ELISA) on serum/oral fluid
-virus isolation and PCR
-histopath./IHC on lung or tracheal tissue
How is swine influenza controlled?
-biosecurity
-vx of staff
-vx of swine
What are the characteristics of PRRS?
-enveloped, single-stranded, positive-sense RNA genome
-genotypes 1 and 2
-most economically significant swine disease
-highly infectious
-all ages affected
-component of porcine resp. disease complex
What is the pathogenesis of PRRS?
-transmitted via direct contact, vertical, parenteral, fomites
-virus found in saliva, urine, semen, feces, milk, nasal secretions, etc. due to viremia
-shedding for a minimum of 1-2 mo.
-piglets from infected sows can be PIs and shed for nearly 160 days
-incubation period of 14 days
-primary replication in lymphoid tissues
-can cross placenta in late gestation
What are the respiratory clinical signs of PRRS?
-interstitial pneumonia
nursing piglets:
-dyspnea and increased mortality
nursery/growing/finishing pigs:
-fever
-depression
-lethargy
-sneezing
-dyspnea
-ear cyanosis
-increased mortality
breeding age pigs:
-anorexia
-fever
-lethargy
-depression
-resp. distress
-mild “blue ears”
What are the reproductive clinical signs of PRRS?
-lower conception rate
-premature farrowing
-late term abortions
-stillborn or weak piglets
-mummified fetuses
How is PRRS diagnosed?
-antibody response/ELISA
-virus isolation and RT-PCR
-histopath./IHC
How is PRRS controlled?
-control program on a herd-by-herd basis
-herd immunity or eliminate through depopulation
-good biosecurity
-early weaning and isolation of piglets
-regular serologic monitoring and removal of PI piglets
-vaccination
What are the general characteristic of porcine circovirus?
-non-enveloped, single-stranded DNA genome
-transmitted oral-nasal and direct contact
-virus found in nasal, ocular, bronchial secretions; saliva, urine, feces, milk, semen (viremia)
-shed for up to 22 weeks
-incubation period of 14 days
Which disease complexes are associated with porcine circovirus?
-porcine resp. disease complex
-porcine multisystemic wasting syndrome
-porcine dermatitis and nephropathy syndrome
-repro. disease
Which clinical signs are associated with porcine resp. disease complex?
-pulmonary edema
-tan and firm lungs
Which clinical signs are associated with porcine multisystemic wasting syndrome?
-progressive growth retardation
-dyspnea
-pallor
-jaundice
-diarrhea
-palpable inguinal lymphadenopathy
-rough hair coat
-low viability and death
Which clinical signs are associated with porcine dermatitis and nephropathy syndrome?
-immune complexes deposited in glomeruli and vessels
-red-purple macules and papules on skin
-anorexia
-prostration
-stiff gait/reluctance to move
-eventual death from acute renal failure
Which clinical signs are associated with porcine circovirus repro. disease?
-late-term abortions and stillbirths
-early embryonic death
-decreased repro. performance
How is porcine circovirus diagnosed?
-clinical findings/lesions
-antibody response/ELISA
-PCR
-histopath./IHC
How is porcine circovirus controlled?
-good biosecurity
-euthanasia of all animals with PMWS
-control of other infection types
-vaccination
What are the characteristics of porcine parvovirus?
-non-enveloped, single-stranded DNA genome
-extremely resistant to disinfectants
-ubiquitous and often subclinical
-oral-nasal, transplacental, and venereal transmission
-virus in secretions, excretions, farrowing remains (viremia)
-prefers cells with high replicative activity
What are the clinical signs of porcine parvovirus?
-stillbirth
-mummification
-embryonic death
-infertility
-abortions are NOT common
How is porcine parvovirus diagnosed?
-clinical signs
-PCR
-paired serum samples for antibody response
How is porcine parvovirus controlled?
-good biosecurity
-seronegative replacements and quarantine
-vaccination before breeding
-planned exposure of seronegative gilts prior to breeding
What are the characteristics of the swine enteric coronaviruses?
-enveloped, single-stranded, positive-sense RNA genome
-antigenically distinct with no cross protection between the viruses
Which enteric coronaviruses are of importance?
-transmissible gastroenteritis virus
-porcine epidemic diarrhea virus
-swine acute diarrhea syndrome coronavirus
-porcine deltacoronavirus
What is the pathogenesis of enteric coronaviruses?
-all ages are susceptible
-high mortality in piglets
-transmitted fecal-oral, aerosol, direct contact, fomites
-shedding up to 10 weeks
-incubation period of 18 hrs to 3 days
-clinical signs for 7-10 days
-replication in small intestinal villi
-no longer considered reportable
What are the clinical signs of epidemic forms of enteric coronaviruses?
-vomiting
-watery diarrhea
-dehydration
-shivering
-excessive thirst
-rapid weakening and death
-anorexia
-agalactia
What are the clinical signs of endemic forms of enteric coronaviruses?
-diarrhea
-dehydration
-runts
-slow growth
How are enteric coronaviruses diagnosed?
-clinical signs + atrophic enteritis
-ELISA
-RT-PCR
-histopath./IHC/FAT
How are enteric coronaviruses controlled?
-good biosecurity
-seronegative replacements and quarantine
-vaccines prior to farrowing
-planned exposure of pregnant sows
What are the characteristics of pseudorabies?
-Herpesviridae family
-enveloped, double stranded DNA
-primary host is swine, but has secondary hosts
-all 50 states considered FREE in commercial pigs
-transmitted oral-nasal, direct contact, fomites, aerosol, feed/water
-shedding 2-5 days post infection up to 2 weeks; can reoccur
-viral sources are saliva, nasal secretions, tonsillar epithelium, vaginal/preputial secretions, milk, urine (viremia)
-reportable
What are the clinical signs of pseudorabies?
nursing piglets:
-CNS disease
-high mortality
weaned pigs:
-resp. disease
-possible CNS
older pigs:
-low mortality
-repro. signs
How is pseudorabies diagnosed?
-ELISA
-PCR
How is pseudorabies controlled?
-vaccination
-oral vx in wild boar pop.
-eradication programs by country and herd
What are the characteristics of classical swine fever?
-Flaviviridae
-enveloped, neg.-sense ssRNA
-eradicated from US
-transmission via oral-nasal, direct contact, fomite, uncooked waste/pork
-reportable
What are the characteristics of African swine fever?
-Asfarviridae
-enveloped, dsDNA
-present in wild boars in Europe; outbreaks is Asia, Africa, Europe, and Americas
-transmission via TICKS, direct contact, fomites, uncooked waste/pork
-reportable
What are the clinical signs of the swine fevers?
-generalized hemorrhages
acute:
-high fever
-huddling
-weakness
-lethargy
-anorexia
-conjunctivitis
-constipation or diarrhea
-ulcers
-leukopenia
-skin hyperemia
-cyanosis
-death
chronic:
-lower fever
-anorexia
-depression
-leukopenia
-constipation or diarrhea
-coughing
How are the swine fevers diagnosed?
-viral neutralization/Ab response
-RT-PCR or FAT
How are the swine fevers controlled?
-screening and quarantine
-biosecurity
-control of importations
-heat-treatment of waste food
-vaccines for CSF; none for ASF
-proper quarantine, movement restrictions, and culling during outbreaks
What is the most important thing about vesicular diseases?
all of the vesicular diseases present similarly to FMDV
What are the characteristics of foot-and-mouth disease virus?
-small, non-enveloped, pos-sense ssRNA
-seen in all cloven-hooved species
-swine are an amplifier host
-highly contagious
-incubation period of 2 days
-transmitted via oral-nasal, aerosol, direct contact, fomites
-found in all secretions and vesicular fluids
-severe clinical signs in pigs
What are the characteristics of vesicular stomatitis virus?
-found in EQUIDS, ruminants, swine, humans
-transmission by flies, direct contact
-virus found in vesicle fluid
-reportable
What are the characteristics of swine vesicular disease virus?
-found in swine
-US is FREE
-transmission by direct contact, fomites
-virus found in oral secretions, feces, urine, semen
-reportable
What are the characteristics of vesicular exanthema of swine virus?
-found in swine, SEALS, CETACEANS
-eradicated in swine
-transmission by direct contact
-virus found in vesicle fluid, oral/nasal secretions
-reportable
What are the characteristics of senecavirus A?
-found in swine, cattle, MICE
-transmission by direct contact, fomites, oral-nasal
-virus found in oral/nasal secretions, feces
-NOT reportable
What are the clinical signs of the vesicular diseases?
-difficulty walking
-detached hoof
-ruptured vesicles
How are the vesicular diseases diagnosed?
-ELISA
-RT-PCR
How are the vesicular diseases controlled?
-screening/quarantine
-control of importations
-heat-treatment of waste food
-vaccines
-quarantine, movement restriction, culling, cleaning/disinfection during outbreaks
