Lecture 6: Canine Viruses 1 Flashcards

1
Q

What is the family and subfamily of canine herpes virus

A
  • Family: Herpesviridae
  • Subfamily: Alphaherpesvirinae
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2
Q

List 5 common canine respiratory viruses

A
  • Canine Influenza
  • Canine Herpes virus 1
  • Canine adenovirus 2
  • Canine distemper virus
  • Canine para influenza
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3
Q

Describe the pathogenesis of canine herpes virus in adults, neonates, and fetuses

A
  • Pathogenesis:
    o Adult: infect via resp/repro tract = localized infection
     Quick acute infection (viremia) -> latency
    o Neonate: infect via ingest/inhale in birth canal/contact/fomites
     >2 week: viremia and acute local infection
     < 1 week: epithelial cell replication, leukocyte associated viremia = necrotizing vasculitis or like adult infection
    o Fetus: infect in utero
     leukocyte associated viremia = necrotizing vasculitis
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4
Q

What are the clinical signs of canine herpes virus in adults and pregnant animals

A

o Adults; subclinical (latent), mild rhinitis, vesicular vaginitis, posthistis
o Pregnant animals: early and late term abortion, still birth

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5
Q

What are the clinical signs of canine herpes virus in neonatal animals - describe the histological lesions you would expect

A

o Neonate: eosinophilic intranuclear inclusions surrounded by clear halo and marginated chromatin = in liver/adrenal glands/lungs/spleen/kidney/lymph node
 Kidney: petechiae of renal cortex, tubular necrosis,
 Liver: multifocal necrosis and
 Lungs: small coalescing pale foci of necrotizing interstitial pneumonia – fibrin
 Eye; corneal edema/cataracts
 Bran: viral nucleic acids in cerebellum and cerebrum

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6
Q

How to diagnose canine herpes virus (3 ways)

A
  • Dx: virus isolated from fresh lung/liver/kidney/spleen
    o Histology for intra-nuclear inclusion bodies
    o Virus neutralization assay (OVC lab)
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7
Q

How to control/prevent canine herpes virus

A
  • Control: no vaccine – colostrum provides passive immunity
    o C-section prevent contamination at birth (may already be infection from placenta)
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8
Q

What family is the agent for Canine infectious hepatitis

A
  • Family: Adenoviridae
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9
Q

What are the viral characteristics of agent for Canine infectious hepatitis

A
  • Virus: non-enveloped, with pentons that have projecting fibres (allow attachment to receptors
    o Virus stable in environment
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10
Q

You may see intranuclear eosinophilic inclusions in a
section of liver infected with
A Herpesvirus
B Adenovirus
C Pox virus
D Pestivirus
E Coronavirus

A

A

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11
Q

You may see intranuclear basophilic inclusions in a
section of liver infected with
A Herpesvirus
B Adenovirus
C Pox virus
D Pestivirus
E Coronavirus

A

B

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12
Q

Two of the organs impacted by canine adenovirus- 1 infection is
the brain and kidney. What are the mechanisms of pathogenesis
of brain and kidney lesions? (3 marks).

A

Brain:
- endothelial cell damage cytopathic effect due to direct viral replication
- type 3 HS due to circulating immune complexes that can deposit in blood vessels and induce vasculitis

Kidney:
- tubular epithelial cells and endothelial cells
- type 3 HS due to circulating immune complexes that can deposit in kidney tubule epithelium and impact filtration ability or deposit in blood vessels of kidney and induce vasculitis

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13
Q

What a type 3 HS? What are the 2 types?

A
  • Type 3 HS: antibody/antigen complex
    o Circulating – deposit in vessel walls (=vasculitis) or in kidney (= damage filtration)
    o Local/Arthus rxn – attract complement = attract neutrophils = tissue damage
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14
Q

What does CAV1 cause

A
  • Canine Adenovirus 1 = infectious canine hepatitis
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15
Q

What are the target species of CAV1

A

o Target: dog/coyote/fox/canid/bears – subclinical dz widespread

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16
Q

What is the time to infection of CAV1

A

o Time: infection clinically significant <1yr (but unvx = can get any age)

17
Q

How is CAV 1 transmitted

A

o Transmit: fomites/oronasal maybe ecto-parasite (not aerosol)
 Virus excreted acutely (5-10day) in saliva/feces/resp mucus and chronically in urine (6-9 moths after)

18
Q

What is the pathogenesis of CAV1

A

o Pathogenesis: viral ingestion > tonsil cervical LN/thoracic duct/blood in 5 days
 Viral replication in cells = cytopathic effect: hepatocyte (acute hepatitis)/renal tubule (nephritis)/vascular endothelium (hemorrhage/DIC)
 Antibody production = complex formation = circulating (renal damage) and local (corneal edema/opacity type 3 HS
 Both types of pathogenesis can affect brain

19
Q

What are the clinical signs, bloodwork, and histopath lesions of CAV1

A

o Clinically: lethargy/pale MM/tender abdomen/icteric/vomiting

 BW: pyrexia/leukopenia/lymphocytosis/neutrophilia/high ALP/coagulopathy/proteinuria/neutralizing Ig

 blue eyes (anterior uveitis/corneal edema/opacity – will resolve spontaneously)
 Multifocal lung hemorrhage
 Thickened/enlarged gallbladder
 Hemorrhagic lymph nodes
 Segmental hemorrhagic enteritis
 Oral mucosal hemorrhage
 Cerebral hemorrhage
 Large/friable/yellow/petechiae liver – basophilic intranuclear inclusionis surrounded by clear zone

20
Q

How to diagnose CAV1

A

o Dx: hematological results, serology, virus isolation/IF or histopath (if postmortem)

21
Q

How to control/prevent CAV1

A

o Control: passive immunity (colostrum) – 5-7 weeks (14-16 week gone)
 Vaccine: killed vaccine – require frequent doses
* Modified live: 3-5 year protection – can localize in kidney = shed in urine or cause blue eye – IM/SC
* Contain either CAV1 or 2 not both

22
Q

What does CAV2 cause

A
  • Canine adenovirus 2 = infectious canine tracheobronchitis (kennel cough)
23
Q

What are the causes of CAV2

A

o Viral cause: Canine parainfluenza virus/adenovirus 2/distemper virus
o Bacterial cause: Bordatella bronchiseptica or B. brronchiseptica commonest
 Pseudomonas
 E. coli
 Klebseilla pneumoniae
 Streptococcus

24
Q

What are the risk factors of CAV2

A

o Risk factors: high density housing, mixing dogs, stress, contact with wildlife/rodent/cat (B. brronchiseptica hosts), airway dz

25
Q

What are the features (family/type) of the viruses causing CAV2

A

o Virus: Adenoviridae (dsDNA) or Paramyxoviridae (-ssRNA)

26
Q

how is CAV2 transmitted

A

o Transmit: ocular/resp secretions – aerosols/direct/fomite = very contagious
 Shed 8-10 day post infection (bordatella shed = 3 months)

27
Q

What are the clinical signs of CAV2

A

o Clincically:
 Uncomplicated: harsh dry cough/watery nasal discharge/pharyngitis/tonsiltis
* Virus rerplicate in resp epithelium
* Self limiting – reduce stress/exercise (mild 1-2 wk, severe 3-4 wk)

 Complicated: lethargy/fever/anorexia/dry hacking honking cough/gagging
* Young unvx puppies/immunocompromised/old
* Viirrus and bacteria replicate in resp epithelium = can’t generate Ig response = viremia/2 bacterial infection

28
Q

How to control CAV2

A

o Control: modified live vx: DAPPV (distemper/adenovirus/parainfluenza/parvo) – also prevent against CAV1
 Modified live parainflenza avirulent intranasal bordatella vx

29
Q

What is the family and subtypes of canine influenza

A
  • Canine influenza
    o Family: Orthomyxoviridae
    o Subtype: H3N8 and H3N2
30
Q

How did canine influenza develop

A

o Antigenic shift: related to equine influenza (mutated into the canine population)

31
Q

What is the target cells of canine influenza virus

A

o Pathology:
 Target cell: macrophages + resp epithelium
 Influenza viral antigen in alveolar macrophage

32
Q

Can H1N1 or H5N1 transmit to dogs

A

o H1N1 can transmit to dogs but not effectively
o H5N1 (HPAI) can. Transmit to dogs (consume infected animals)

33
Q

What are the clinical signs of canine influenza

A

o Clinically: unreliable clinical signs – cough/sneeze/nasal discharge

34
Q

How to control canine influenza

A

o Control: monovalent/bivalent vx for H3N8/H3N2 – will reduce severity/duration not prevent infection

35
Q

How to diagnose canine influenza

A

o Dx: viral isolation/immunoassay/RT-PCR/serology for viral Ig