Family Adenoviridae

1
Family Adenoviridae

• ds DNA
• Only DNA family forming basophilic intranuclear
  inclusion bodies
• Hemagglutinates
• Environmentally stable but easily inactivated by
  disinfectants
• Penton fibers project from vertices
• Genera Mastadenovirusmammalian, 1 penton fiber
  per vertex
• Genera Aviadenovirusavian, each penton fiber is
  bifurcated
• All have narrow host range mostly subclinical
  infections
• Associated with long periods of latency

2
Infectious Canine Hepatitis Syn ICH, Rubarths Dz

• Etiologic Agent Canine adenovirus 1
• Host Family Canidae (domestic wild) Ursidae
  (bears)
• Distribution worldwide
• Transmission mainly ingestion of urine, feces,
  or saliva, also conjunctival or aerosol routes
• Pathogenesis initial infection in tonsilar
  crypts Peyers patches
• Clinical Feature viremia leading to hemorrhages
  necrosis of target organs (liver, kidneys,
  spleen, lungs), mostly asymptomatic, can lead to
  Corneal Edema (blue eye), Glomerulonephritis,
  DIC, Encephalitis (foxes)
• Vx inactivated MLV CAV-1 used,
  cross-protection given with CAV-2 vx
• DDX?

3
Canine Infectious Tracheobronchitis Syn ITB,
Kennel Cough

• Etiologic Agent CAV-2 (also canine parainfluenza
  virus 2, Bordetella bronchiseptica, Mycoplasma
  cynos)
• Host Canines
• Distribution worldwide
• Transmission highly contagious via aerosolized
  microdroplets
• Pathogenesis self-limiting (2 wks) upper
  respiratory disease
• Clinical Feature nonproductive cough
• Vx CAV-2 MLV
• DDX?

4
Equine Adenovirus Infections

• Etiologic Agent Equine adenovirus 1
• Host horses, mostly Arabians due to TB cell
  immunodeficiency
• Distribution worldwide
• Transmission
• Pathogenesis fatal, horses susceptible to a wide
  range of pathogens as maternal antibodies wane
  (usually within 3 months)
• Clinical Feature bronchiolitis and pneumonia
• Vx
• DDX?

5
Family Retroviridae

• Enveloped, diploid sense ss RNA, does not
  serve as mRNA
• Contains Reverse Transcriptase
• Replicates in cytoplasm nucleus, NO inclusion
  bodies
• All RNA oncogenic virusesRetroviridae
  (leukemias, lymphomas, sarcomas)
• Fragile viruses inactivated by detergents but
  resistance to UV light
• Gag gene (capsid), pol gene (reverse
  transcriptase), env gene
• Genera (Alpha, Beta, Gamma, Delta,
  Epsilon)-retrovirus, (Lenti, Spuma)-virus
• Type Aintracellular noninfectious-gtType
  Bextracellular eccentric core, Type Ccentral
  core, oncogenic, Type Dtubular core
• Acute transformingV-onc, replication
  defective
• Chronic transformingV-onc-, cause cancers late
  after infection

6
Bovine Leukemia Syn Enzootic bovine leukosis

• Etiologic Agent Deltaretrovirus v-onc
• Host cattle
• Distribution worldwide, seen more in dairy vs.
  beef due to lifespan
• Transmission via blood lymphocytes (horizontal
  vertical trans.)
• Pathogenesis target cellsB lymphocytes,
  outcomefailure of infection, asymptomatic
  infections, permanent infection, infected cattle
  developing lymphosarcoma in cattle 4-8 yrs old
  (1 infected)
• Clinical Feature high antibody levels easy to
  detect
• Vx No, test slaughter animals over 6 months
  old
• DDX? Compare to Sporadic Bovine Leukosis
  (SBL)cattlelt3yrs old, unknown agent. Calf form
  lt6mo., enlarged lymph nodes, 100 fatal, Thymic
  form 6mo-2yrs, bloat edema, 100 fatal,
  Cutaneous form 1-3yrs old, rare, skin plaques

7
Feline Leukemia Sarcoma

• E

• Etiologic Agent Gammaretrovirus, noncytopathic,
  v-onc-, Subgroup A transmitted cat to cat, p27
  protein free in plasma detected by tests
• Host domestic some wild cats
• Distribution worldwide
• Transmission via saliva (grooming) iatrogenic,
  continual shedding
• Pathogenesis multiplies in T B lymphocytes
  myeloid cells, FOCMA antigen present on
  transformed cells FOCMA antibody lyses tumor
  cells via ADCC complement activation
• Clinical Feature 1)most catsself-limiting
  infection, 2)most at riskpersistent active
  infection (persistent viremia
  immunosuppression), 3)latent infectionsdoes not
  shed the virus
• Vx MLV and genetically engineered vx
• FeSv associated w/fibrosarcomas in cats lt5 yrs
  old, FeLV needed for replication

8
Avian Leukosis Syn Big Liver Dz.

• E

• Etiologic Agent Alpharetrovirus, v-onc-,
  Subgroups AB most important, CD infrequent, E
  genetically inhereted nononcogenic
• Host chickens (not turkeys)
• Distribution worldwide
• Transmission vertical or horizontal lt5 days
  oldviremic for life, gt5 days oldtransient
  viremia due to antibodies
• Pathogenesis B lymphocytes in bursa of Fabricius
• Clinical Feature Lymphoid leukosis (big liver
  dz), Osteopetrosis less common not neoplastic
• Vx terminate breeder stock, no vx
• DDX? Without nerve or ocular involvement seen in
  Mareks Dz.

9
Feline Immunodeficiency Dz

• E

• Etiologic Agent Feline Lentivirus, Subgroups A-D
  (no cross-protection), test for p24 core antigen
• Host Domestic cats some wild felidae, not
  zoonotic
• Distribution
• Transmission lifelong infection, via saliva in
  bites (free-roaming)
• Pathogenesis immunosuppression, tropism for
  helper T cells MØ
• Clinical Feature Acute, Latent, and Terminal
  stages
• Vx questionable efficacy
• DDX?

10
Equine Infectious Anemia Syn EIA, Swamp Fever

• E

• Etiologic Agent Equine lentivirus
• Host Equids
• Distribution
• Transmission transfer of blood (mechanically by
  tabanids, vertical)
• Pathogenesis replicates in macrophages
  lymphocytes, lifelong cell associated viremia,
  vasculitis, anemia, glomerulonephritis
• Clinical Feature Acute 80 mortality, Subacute,
  Chronic, test via Coggins test recommended
  destruction or isolation
• Vx
• DDX?

11
Caprine Arthritis-Encephalomyelitis

• E

• Etiologic Agent Caprine lentivirus
• Host goats
• Distribution worldwide
• Transmission vertically by colostrum milk
• Pathogenesis multiplies in monocytes
  macrophages
• Clinical Feature arthritis most common,
  Encephalitis 1-5 month kids (fatal), Interstitial
  pneumonia in adults (fatal), Mastitis
• Vx No, test slaughter
• DDX?

12
Family Rhabdoviridae

• E

• Bullet-shaped, - sense ss RNA
• Antibodies directed against envelope G proteins
• Defective interfering DI particles formed
  during replication with truncated genome
• Thermolabile, sensitive to UV light, and readily
  inactivated by detergents
• Some cause rapid cytopathology others
  noncytopathic

13
Rabies

• E

• Etiologic Agent Genus Lyssavirus, 6 strains in
  N.A.
• Host all warm-blooded animals (not birds), cats
  more susceptible than dogs, bats not a true
  reservoir host
• Distribution worldwide
• Transmission bite or scratch, also aerosol in
  bat caves, skunks have high prevalence high
  quantities in their saliva, bats have a
  protracted clinical course
• Pathogenesis from inoculation site to ACh
  receptors centripetally to CNS, furious form in
  limbic system, dumb from neocortex replication,
  centrifugally down peripheral nerves (salivation)
• Clinical Feature death from respiratory failure,
  IP influenced by dose, strain, degree of
  innervation, site (distance) of innoculation
• Vx yes
• DDX?

14
Vesicular Stomatitis (VS)

• E

• Etiologic Agent Genus Vesiculovirus (Indiana,
  New Jerseymost common, Isfahan serotypes)
• Host cattle other ruminants, horses (unlike
  FM), swine, humans
• Distribution Americas Caribbean
• Transmission contact, ingestion, and mainly
  mechanical arthropod
• Pathogenesis systemic viremic phase seen only
  in pigs lab
• Clinical Feature vesicular lesions, profuse
  salivation
• Vx autogenous killed vx, questionable gives
  serologic status
• DDX? Foot and Mouth disease (but horses dont get
  that)

15
Bovine Ephemeral Fever Syn 3-day sickness

• E

• Etiologic Agent Bovine ephemerovirus
• Host cattle water buffalo
• Distribution Africa, Asia, Austrailia (never in
  US)
• Transmission biologically transmitted via
  mosquitoes Culicoides
• Pathogenesis Type 3 immune complex
  hypersensitivity, in buffy coat
• Clinical Feature sudden onset, dramatic recovery
  is pathognomonic
• Vx attenuated vx, also use vector control
• DDX?

16
Family Picornaviridae

• Nonenveloped linear sense ssRNA
• Do not produce inclusion bodies
• Multiple serotypes without cross-protection
• Very resistant in the environment stable

17
Foot-and-Mouth disease FMD Syn Aphthous fever,
epidemic aphthae

• E

• Etiologic Agent Aphthovirus
• Host cattle, sheep, goats, swine, buffallo,
  ruminants, NOT horses
• Distribution endemic in Asia, Africa, Mid East,
  and S. America
• Transmission inhalation of aerosols, feeding
  uncooked garbage
• Pathogenesis lt 5 mortality rate tiger-striped
  heart, up to 2 yrs as a carrier state (no
  carrier stage in pigs)
• Clinical Feature Vesicles on tongue, lips, gums,
  palate, teats, etc., immunity is type specific
  not life-long
• Vx inactivated MLV where endemic, test
  slaughter elsewhere, notifiabe dz., human
  infections are subclinical

18
Porcine Polioencephalomyelitis Syn
Teschen/Talfan Dz.

• E

• Etiologic Agent Porcine enterovirus 1
• Host Swine, usually in pigletts lt 12 wks old
• DistributionTalfan more common worldwide,
  Teschen Czech
• Transmission ingestion
• Pathogenesis virus replicates in GIT without
  forming diarrhea, viremia spreads dz to CNS
• Clinical Feature CNS signs, teschen form
  mortality 75
• Vx not done in US, only done where Talfan form
  is
• DDX?

19
Porcine Enteroviruses 2-11

• E

• Etiologic Agent porcine enteroviruses 2-11
• Host swine
• Distribution
• Transmission
• Pathogenesis
• Clinical Feature seen with SMEDI, diarrhea
  pericarditis
• Vx
• DDX?

20
Avian Encephalomyelitits Syn Epidemic tremor

• E

• Etiologic Agent Avian enterovirus
• Host all birds
• Distribution worldwide
• Transmission fecal-oral route
• Pathogenesis
• Clinical Feature CNS signs, Mortality may be
  gt50
• Vx
• DDX?

21
Encephalomyocarditis

• E

• Etiologic Agent Cardiovirus
• Host humans, swine, monkeys, cattle, horses,
  rodents reservoir
• Distribution
• Transmission fecal-oral route
• Pathogenesis pathognomonic cardiac lesions, esp.
  in R ventricle
• Clinical Feature sudden death, mortality can be
  gt 100 in pigletts
• Vx inactivated given to sow to pass passive
  immunity to pigletts, mainly do rodent control
• DDX?

22
Family Paramyxoviridae

• Every member causes a respiratory dz.
• Intracytoplasmic inclusion bodies
• Pleomorphic virions with syncitia formation
• H (hemagglutinin) attachment
• F (fusion protien) penetration, important in
  persistant infections cell-cell spread
• N (neuraminidase) enzyme
• Genus Morbillivirus also intranuclear inclusion
  bodies

23
Bovine Respirovirus Disease Syn Bovine
Parainfluenza Virus 3 Disease

• E

• Etiologic Agent Bovine respirovirus
• Host cattle sheep
• Distribution worldwide
• Transmission awrosolization contaminated
  fomites
• Pathogenesis high morbidity, low mortality,
  contributes to shipping fever complex
• Clinical Feature Hemagglutinates
• Vx MLV intranasal or parenteral vx, induces
  mucosal IgA antibodies
• DDX? Infectious Bovine Rhinotracheitis

24
Newcastle Disease

• E

• Etiologic Agent avian rubulavirus 1 with strains
  varying in virulence, Velogenic strains are
  highly virulent
• Host almost all avians (gallinaceous birds)
• Distribution worldwide
• Transmission aerosols ingestion, virus shed
  during IP onward, persistant carrier state
• Pathogenesis Viscerotripic velogenic ND
  (exotic)hemorrhages in GID 100 mortality,
  velogenic ND (endemic)no GIT lesions
• Clinical Feature Notifiable Dz
• Vx naturally occuring lentogenic (least
  virulent) strains given
• Dz is zoonotic, but not threatening

25
Canine Rubulavirus

• E

• Etiologic Agent canine parainfluenza virus 2
  (CPiV)
• Host dogs
• Distribution worldwide
• Transmission aerosolized microdropletes
• Pathogenesis part of kennel cough syndrome,
• Clinical Feature does not multiply in
  macrophages, only URT
• Vx intranasal parenteral vx
• DDX?

26
Canine Distemper Syn Hardpad Disease

• E

• Etiologic Agent canine morbillivirus
• Host domestic wild dogs, Ursidae(bears),
  Mustelidae(ferrets), and Procyonidae(raccoons)
  families, CNS infections in exotic Felidae
• Distribution worldwide
• Transmission inhalation
• Pathogenesis intranuclear intracytoplasmic
  inclusion bodies
• Clinical Feature survivors have prolonged
  immunity, fever, leukopenia, GI respiratory
  catarrh, pneumonic CNS signs
• Vx MLV every 2-4 wks from 6 wks old, titer of
  gt1100 protects you
• DDX? Infectious canine hepatitis

27
Rinderpest Syn Cattle Plague

• E

• Etiologic Agent Bovine morbillivirus
• Host cattle buffalo (also seen in sheep,
  goats, swine)
• Distribution endemic in Asia, Africa, Middle
  East
• Transmission inhalation, oral, no carrier state
• Pathogenesis replicates in the palatine tonsils
  lymph nodes causing destruction of lymphocytes
• Clinical Feature virus is excreted prior to
  showing clinical signs, morbidity mortality
  100
• Vx MLV, recovered animals have lifelong immunity
• DDX?

28
Bovine Respiratory Syncytial Dz

• E

• Etiologic Agent bovine pneumovirus
• Host cattle sheep
• Distribution worldwide
• Transmission aerosolization
• Pathogenesis complete loss of ciliated
  epithelium, so 2 bacterial inf.
• Clinical Feature morbidity is very high,
  mortality is low, no hemagglutination
• Vx inactivated MLV vx
• DDX? Bovine Respirovirus Dx. Bovine Herpes
  Virus 1 (IBR)

29
Family Orthomyxoviridae

• Segmented genome w/genetic reassortment
  defective interfering particles
• Require host DNA transcription to replicate
• Replication via cap snatching in the nucleus
• Type based on RNP M1 matrix protein
• Subtypes based on H (hemagglutinin) NA
  (neuraminidase)
• H antibodies prevent attachment, NA antibodies
  decrease spread but dont neutralize free virions
• Penetration via endocytosis, uncoating via M2 ion
  channel

30
Equine Influenza

• E

• Etiologic Agent Influenza virus A 2 types
  A/equine/Prague/1/56/(H7N7), A/equine/Miami/1/63/(
  H3/N8)
• Host equines (not zoonotic)
• Distribution worldwide, very unstable virus in
  environment
• Transmission aerosolized, no carrier state
• Pathogenesis replicates in respiratory
  epithelial cells
• Clinical Feature high morbidity, rare mortality,
  acute, contagious, febrile respiratory dz,
  Hemagglutinates
• Vx inactivated bivalent vx., also use 30 day
  quarantine
• DDX? Common cold

31
Swine Influenza Syn Swine flu, Hog flu

• E

• Etiologic Agent Influenza virus A,
  A/swine/Iowa/15/30/(H1/N1)
• Host swine, humans, and turkeys
• Distribution worldwide
• Transmission aerosolization, outbreaks most
  common in fall/winter due to indoor housing
• Pathogenesis replication in respiratory
  epithelium
• Clinical Feature herd disease, mortality low
  unless 2º bacterial inf. , Hemagglutinates
• Vx yes, but not good results so not widely used
• DDX?

32
Avian Influenza Syn Fowl Plague

• E

• Etiologic Agent Influenza virus A, unstable
  virus with changing genome, some are zoonotic
• Host turkeys more than chickens, migratory water
  fowl reservoir
• Distribution
• Transmission aerosolization, ingestion
• Pathogenesis replication in respiratory GIT,
  highly pathogenic avian influenza A virus (HPAI)
  causes viremia
• Clinical Feature respiratory, enteric, and/or
  CNS lesions, hemagglutinates
• Vx no, quarantine eradication, Notifiable Dz
• DDX? Newcastle Dz.

33
Family ReoviridaeReoRespiratory Enteric Orphan

• 3 concentric capsid layers
• dsRNA divided into 10-12 segments
• Perinuclear inclusion bodies
• Cytoplasmic replication
• Genetic reassortment

34
Bluetongue Syn Soremuzzle

• E

• Etiologic Agent Ovine orbivirus, USserotypes 2,
  10, 11,13, 17
• Host sheep white-tailed deer
• Distribution worldwide
• Transmission noncontagious, arthropod-borne
  seasonal dz (Culicoidesbiological vectors)
• Pathogenesis replicates in hematopoietic
  endothelial cells cause degenerative necrotic
  changes
• Clinical Feature lameness (coronitis), cyanosis
  of tongue, morbidity 80, mortality 50,
  hydraencephaly porencephaly in sheep, cattle
  have oral lesions like FMD may be reservoirs
• Vx MLV against serotypes 10, 11, 17 in US (types
  2, 13 not seen)
• DDX? FMD in cattle

35
African Horse Sickness (AHS)

• E

• Etiologic Agent Equine orbivirus, 9 serotypes
• Host horses, donkeys, mules, dogs that eat
  infected horse meat
• Distribution endemic in Africa, outbreaks in
  Middle East, N Africa, Spain, Portugal, Indai,
  never in Western hemisphere
• Transmission Culicoides spp. vectors
• Pathogenesis replicates in endothelium causing
  1º and 2º viremia
• Clinical Feature pulmonary/acute form mortality
  95 frothy nasal discharge, cardiac/subacute
  form mortality 50-70 edema, also mild form,
  Notifiable Dz
• Vx MLV in endemic areas, 60-day quarantine on
  horses entering US from Africa or other areas
• DDX?

36
Genus Rotavirus

• E

• Etiologic Agent domestic animals serogroup A
• Host neonated of domestic animals and birds and
  humans
• Distribution worldwide
• Transmission ingestion
• Pathogenesis infect mature enterocytes cause
  villus atrophy, self-limiting infection
• Clinical Feature morbidity 100, mortality 0-50
• Vx no carrier starte, inactivated vx given to
  dams to promote high levels of abs in the
  colostrum milk
• DDX?

37
Viral Arthritis Tenosynovitis

• E

• Etiologic Agent avian orthoreoviruses (11
  serotypes)
• Host mainly broilers, also in layers turkeys
• Distribution
• Transmission fecal-oral, low level of
  transolvarial transmission
• Pathogenesis
• Clinical Feature morbidity 100, mortality lt2,
  birds sit on their hocks with swollen joints
• Vx Vx breeders so progeny have passive immunity
• DDX?

38
Family Coronaviridae

• Always a carrier state
• Large club-shaped peplomeres
• No inclusion bodies
• Neutralizing abs against S and HE proteins
• S proteinglycoprotein peplomere
• HE proteinhemagglutinin-esterase in group 2
  coronaviruses toroviruses
• M Etransmembrane proteins, Nnucleoprotein
• Group 1 Coronaviruses (mammalian) related
  cross-protect
• Group 2 Coronaviruses (mammal avian) unrelated
  no cross-protection

39
Transmissible Gastroenteritis of Swine (TGE)

• E

• Etiologic Agent porcine coronavirus (related to
  canine feline coronaviruses)
• Host swine, also dogs cats can become
  infected, also starlings
• Distribution worldwide
• Transmission fecal-oral, mechanical, chronic
  carrier pigs shed 10 wks, morbidity 100
• Pathogenesis destroys villous enterocytes of
  small intestine -gt villous atrophy -gt watery
  diarrhea
• Clinical Feature Epidemic TGE new infection,
  mortality lt2 wks age 100, Endemic TGE
  motalitly 10-20
• Vx attenuated vx given 3 wks prior to farrowing,
  virulent virus can be given to pregnant sows
  since no viremia
• DDX?

40
Feline Infectious Peritonitis (FIP)

• E

• Etiologic Agent Feline coronavirus (FCoV)
  feline enteric coronavirus (FeCV) and feline
  infectious peritonitis virus (FIPV)
• Host domestic wild cats
• Distribution worldwide
• Transmission shed in feces, urine, saliva,
  aerosol, in utero
• Pathogenesis in vivo mutation of FeCV into FIPV
  in S glycoprotein to infect monocytes
  macrophages, multiple pyogranulomatous
  lesionspathognomonic, mortality 100, ABs not
  protective, Dz depends on CMI response, very high
  serum titers!
• Clinical Feature classic/wet form75 of cases,
  no CMI response, type 3 hypersensitivity, leakage
  of plasma proteins fluid into body cavities,
  distended abdomen, Noneffusive/dry25 of cases,
  due to partially protective CMI response,
  protracted course
• Vx MLV intranasally to elicit CMI with low AB
  formation

41
Bovine Coronavirus Enteritis

• E

• Etiologic Agent bovine coronavirus
• Host cattle
• Distribution
• Transmission fecal-oral, inapparent persistent
  carriers
• Pathogenesis diarrhea more severe than
  rotavirus, multiplies in small large intestines
  destroys absorptive epithelium
• Clinical Feature morbidity 100, mortality
  0-50, commonly in calves 1-4 wks of age
• Vx Vx dam to elevate AB levels in colostrum
• DDX? Rotavirus

42
Enephalitis-Vomiting and Wasting Disease Complex
of Swine

• E

• Etiologic Agent hemagglutinating
  encephalomyelitis virus (HEV)
• Host piglets lt4wks old
• Distribution N.A., Europe, Australia
• Transmission aerosols, ingestion
• Pathogenesis replicates in mucosa, spreads to
  CNS via peripheral nerves, no viremia
• Clinical Feature mostly subclinical,
  peracute/acute form morbidity mortality 100
  in pigs lt2 wks, vomiting wasting disease (VWD)
  in pigs lt4wks has a longer dz course but
  mortality still 100, diagnose via
  hemagglutination inhibition test
• Vx No, rely on endemic exposure
• DDX? Psuedorabies

43
Avian Infectious Bronchitis Syn Gasping Disease

• E

• Etiologic Agent avian coronavirus, 8 serotypes
• Host chickens
• Distribution worldwise
• Transmission aerosols, ingestion, can have short
  carrier state
• Pathogenesis replicates in respiratory tract,
  then viremia, can damage L (only) oviduct,
  nephropathogenic strains enlaged kidneys
• Clinical Feature young chicks morality 25-75,
  layers form misshaped eggs that are not usable
  internal layers, embryonated eggs will be
  dwarfed
• Vx Yes
• DDX?

44
Family Togaviridae

• No inclusion bodies
• Not very stable in environment
• Genus Alphavirus horses humans, biological
  mosquito transmission, not contagious
• Genus Rubivirus humans (German measles)

45
Western, Eastern, Venezuelan Equine Encephalitis

• E

• Etiologic Agent equine alphaviruses
• Host horses humans
• Distribution all only in Americas
• Transmission biological mosquito trans.
• Pathogenesis maintained in endemic cycle of
  birds, epidemic strain arises from mutaion of
  endemic strain
• Clinical Feature WEE least virulent, fatality
  20-40, Highlands J related to WEE, EEE 90
  fatality, VEE virulent subtype 1ABC
• Vx bivalent or trivalent inactivated vx, also
  attenuated vx for VEE
• DDX?

46
Family Flaviviridae

• Enveloped, eicosahedral
• Do not form inclusion bodies
• Not stable in the environment
• Used to be part of Togaviridae
• Human Yellow Fever fist named Flavi

47
Bovine Viral Diarrhea-Mucosal Disease Syn BVD-MD

• E

• Etiologic Agent Bovine Pestivirus, Cytopathic
  Noncytopathic (mutates into the cytopathic)
• Host Cattle (beef dairy), also sheep, goats,
  bison, other ruminants swing
• Distribution worldwide
• Transmission highly contagious, cattle with
  persistent infection reservoir, ingestion,
  fomites, transplacental, inhalation
• Pathogenesis replicates in GI Respiratory,
  ulcers causing vesicular syndrome,
  immunosuppression
• Clinical Feature MD portion is what makes dz
  deadly, mortality 100, persistent infections in
  calves Mucosal disease
• Vx attenuated inactivated vx
• DDX?

48
Hog Cholera Syn Swine Fever (NOT African Swine
Fever)

• E

• Etiologic Agent Porcine Pestivirus
• Host Pigs, most important dz of pigs worldwide
• Distribution endemic in Asia, Africa, Central
  South America
• Transmission can survive in frozen pork for
  years, ingested or inhaled
• Pathogenesis replicates in tonsils lymph
  nodes, viremia follows
• Clinical Feature peracuteyoung swine die w/o
  clinical signs, acute moralitly 100,
  subacute-chroniclow to moderate virulence,
  SMEDI, survivors can have lifelong infection,
  Reportable Dz
• Vx attenuated live in endemic areas, quarantine
  in outbreaks, test slaughter in areas without
  disease
• DDX? African Swine Fever, Hog Cholera does not
  hemagglutinate

49
Border Disease Syn Hairy Shakers, Fuzzies

• E

• Etiologic Agent ovine pestivirus
• Host lambs, disease of the fetus/kids, not
  adults
• Distribution worldwide
• Transmission contact w/fluids body secretions,
  vertical trans. only
• Pathogenesis lambs are longterm carries
  continually shed virus
• Clinical Feature CNS disease causing improper
  formation of myeling neurologic signs, haircoat
  is hair instead of wool
• Vx none
• DDX?

50
Louping Ill Syn Ovine Encephalomyelitis

• E

• Etiologic Agent Flavivirus
• Host mostly sheep, sometimes goats, horses,
  cattle, dogs, pigs
• Distribution only in Europe
• Transmission biologically via Ixodid ticks
• Pathogenesis goose-stepping, 2nd dz peak CNS
  signs,
• Clinical Feature mortality 60
• Vx Inactivated vx
• DDX?

51
Japanese Encephalitis

• E

• Etiologic Agent Flavivirus
• Host mostly swine, also horses, dogs, chickens,
  ducks, humans
• Distribution Asia
• Transmission biologically via mosquitos
• Pathogenesis
• Clinical Feature swine have stillbirth
  abortion, horses have fatal encephalitis
• Vx modified live inactivated vx
• DDX?

52
Family Arteriviridae

• Enveloped, eicosahedral
• No inclusion bodies
• Persistent infections
• Not stable in the environment

53
Equine Viral Arteritis (EVA)

• E

• Etiologic Agent equine arterivirus
• Host equine
• Distribution worldwide
• Transmission respiratory, sexual, transplacental
• Pathogenesis abortion storm, vascular necrosis,
  replicates in alveolar macrophages, then lymph
  nodes, carriers are stallions only, not mares
• Clinical Feature mostly asymptomatic, rarely
  fatal, abortion storm
• Vx attenuated live or inactivated vx
• DDX?

54
Porcine Reproductive Respiratory Syndrome (PRRS)

• E

• Etiologic Agent porcine arterivirus
• Host swine
• Distribution Europe North America
• Transmission aerosol, contact, semen
• Pathogenesis replicates in alveolar macrophages,
  then persistent viremia
• Clinical Feature mortality 100 from 2nd
  bacterial infections
• Vx attenuated vx, not in pregnant animals
• DDX?

55
Family Bunyaviridae

• Enveloped, segmented genome
• Several hemagglutinate
• Largest virus family
• Readily inactivated by detergents disinfectants

56
Rift Valley Fever

• E

• Etiologic Agent Phlebovirus
• Host sheep, goats, cattle, humans
• Distribution Africa
• Transmission biological mosquitos, transovarial,
  mechanical
• Pathogenesis viremia 2-5 days, cytopathic
  necrosis of the liver
• Clinical Feature 90-100 abortion storm, kid
  lamb mortality 90, adults 20-60, cattle dz less
  severe 10-30 mortality
• Vx attenuated inactivated
• DDX?

57
Akabane Dz Syn Cache Valley Virus in US

• E

• Etiologic Agent Bunyavirus
• Host cattle, sheep, goats
• Distribution Australia, Japan, Israel, Turkey,
  Africa
• Transmission biologically via mosquitos
• Pathogenesis virus carried to placenta infects
  the fetus, no dz to the dam, fetal infection is
  encephalomyelitis, polymyocitis, abortion
• Clinical Feature surviving fetuses develop
  hydraencephaly, arthrogriposis, cavitation of the
  cerebrum spinal problems
• Vx inactivated in Japan Australia
• DDX?

58
Family Caliciviridae

• Naked, eicosahedron w/cupped shapped capsomeres
• No inclusion bodies
• Rapidly cytopathic
• Resistant to heat disinfectants but inactivated
  at pH 3

59
Feline Calicivirus Infection (FCV)

• E

• Etiologic Agent feline calicivirus
• Host kittens, a main cause of resp. dz in
  kittens, other feline herpes virus 1, rare in
  catsgt1yr old
• Distribution worldwide
• Transmission nasal, oral, conjunctival
• Pathogenesis persists in tonsils oropharyngeal
  tissues, sheds continuously in saliva carrier
  state
• Clinical Feature oral ulcers, highly virulent
  strains produce pulmonary edema interstitial
  pneumonia
• Vx modified live inactivated given in
  combination with FHV1, reduces severity of dz but
  will not protect against getting dz
• DDX? Feline Herpes virus 1 (corneal ulcers)

60
Vesicular Exanthema of Swine San Miguel Sea
Lion Virus

• E

• Etiologic Agent porcine calicivirus
• Host pigs, endemic in marine mammals (sea
  lions)reservoir
• DDX? Foot and Mouth, Swine Vesicular Dz,
  Vesicular Stomatitis

61
Prion diseases Slow Virus InfectionsPrion
Proteinaceous infectious particles

• Prion small protein w/no nucleic acid
• Normal form PrPc, many a-helices
• Abnormal form PrPsc, many ß-sheets
• Very resistant require long autoclaving times
• Cause neurodegenerative diseases with spongiform
  degeneration in the gray matter
• Diseases are irreversible fatal
• Induce no inflammatory or immune response no
  protection

62
Scrapie

• E

• Etiologic Agent PrPsc abnormal isoform of the
  prion protein
• Host sheep, occasionally goats
• Distribution worldwide, except Australia New
  Zealand
• Transmission unknown
• Pathogenesis fatal, neurodegenerative dz with
  intense pruritis
• Clinical Feature long IP (2-4 years), Suffolk
  sheep most susceptible, diagnose via
  histopathologic vacuolation in the brain
• Vx No, Reportable Dz, attempts made at test
  slaughter
• DDX? Psuedorabies

63
Bovine Spongiform Encephalopathy Syn BSE, Mad
Cow Dz, Raging Cow Dz

• E

• Etiologic Agent
• Host adult cattle
• Distribution throughout Europe, not in the US
• Transmission contaminated meat bone meal from
  infected animals
• Pathogenesis
• Clinical Feature not associated with breeds,
  100 mortality, most cattle 3-5 yrs, no pruritis,
  progresses into CNS signs, diagnose via
  histopathologic brain examination of gray matter
• Vx No, submit brains from questionable cattle
  deaths for screening
• DDX?

64
Maedi/Visna Disease

• E

• Etiologic Agent
• Host adult sheep, some goats
• Distribution worldwide
• Transmission aerosolization, ingestion, vertical
  transmission, mechanically
• Pathogenesis lifelong viremia, breed
  susceptibility (Icelandic), clinical disease
  infrequent 5
• Clinical Feature seen in older sheep due to
  varying IP, Maedi (shortness of breath) Ovine
  progressive pneumonia (OPP)respiratory, Visna
  (Wasting)CNS signs encephalomyelitis,
  Arthritis is 3rd form that may occur
• Vx No, antigenic variation prevents viral
  elimination, test slaughter control

65
Family Birnaviridae

• Naked
• 2 molecules of linear, dsRNA
• Segmented
• Stable virus persists in environment a long time

66
Infectious Bursal Dz (IBD) Syn Gumboro Dz.

• E

• Etiologic Agent avibirnavirus, 2 serotypes,
  minimal cross-protection
• Host chickens
• Distribution worldwide
• Transmission highly contagious, fecal-oral, dz
  of broiler chickens
• Pathogenesis necrosis deplesion of bursa of
  Fabricious, survivors are immunosuppressed,
  replicates in GALT, macrophages lymphoid cells,
  then viremia
• Clinical Feature morbidity 100, mortality
  30-90, bursa initially enlarges 5x, then
  atrophies, kidneys also enlarge
• Vx vx breeders, top over little before
  repopulating
• DDX?