Principles and changes with viral disease Flashcards
What factors cause disease outbreaks
Susceptible populations
Changes in the virus
Short lived immunity
Inadequate vaccines
New emerging diseases
Give examples of viral outbreaks in the UK
Avian Influenza
Moo Flu (mammary infection)
Calf respiratory disease
Define sporadic disease
Seen in individual animals, disease occurs infrequently and irregularly
Give examples of feline sporadic disease
feline parvovirus
calcivirus
herpesvirus
feline infectious peritonitis
less common due to vaccinations
Give an example of a bovine sporadic disease
malignant catarrhal fever
What is the economic impact of virus outbreaks?
Costs of lost production
Culling
Banning of imports/exports
Costs of control (vaccines/biosecurity)
What common clinical signs are observed in acute viral disease?
pyrexia
depression
anorexia
What are the clinical signs of cat ‘flu’ (calcivirus, herpesvirus)
Nasal and ocular discharge
pyrexia
anorexia
lethargy
Corneal ulcers (herpes)
Ocular ulceration (calcivirus)
What are the clinical signs of calf respiratory disease?
cough
nasal and ocular discharge
pyrexia
depression
subsequent bacterial infection
What are the clinical signs of canine parvovirus?
Vomiting
bloody diarrhoea
neutropenia
Villus stunting, crypt dilation and necrosis
Vulnerable to secondary bacterial infection
Give examples of lentiviruses in cats?
FIV
FeLV
What is the effect of FIV?
immunosuppression
lymphoma
What is the effect of FeLV?
virus persistence
associated anaemia
lymphoid and myeloid neoplasia
gingivostomatitis
What diseases cause immunosuppression?
FIV
Infectious Bursal Disease
BVDV
Parvoviruses
What viral diseases cause immunopathology?
FIP
Malignant catarrhal fever
What viral diseases cause inclusion bodies?
Some Herpesvirus or Poxvirus infections
e.g. IBR
What viral diseases cause pre-natal infections?
Pestiviruses (BVD, Border disease)
Schmallenberg virus
Parvoviruses
How can canine parvovirus be diagnosed?
Cage side antigen test (SNAP or lateral flow)
Neutropenia in CBC
PCR
How can cat flu be diagnosed?
Oropharyngeal/conjunctival swab
Virus isolation & PCR
How can feline infectious peritonitis be diagnosed?
FeCoV antibody can be measured by does not confirm FIP
Yellow, tacky effusion is highly suggestive of wet FIP
Raised serum gamma globulins
Raised alpha-1 acid glycoprotein
PCR
How is bovine viral diarrhoea (BVD) diagnosed and controlled?
Virus positive (test for antigen)
antibody negative
bulk milk antibody test useful screen
persistently infected animals culled and removed
How is avian influenza diagnosed?
Tracheal, oropharyngeal and cloacal swabs
Fresh tissue samples
Virus detection by RT-qPCR
Sequencing and/or serotyping to confirm virus subtype (e.g. H5N1) and whether high or low pathogenicity
In what ways can viral diseases be controlled?
biosecurity
husbandry
vaccination
Give examples of using biosecurity to control viral diseases
Closed herds
‘stamping out’ - culling infected animals
Consider routes of disease transmission:
- vectors e.g., insecticides on animals
- boot dips
- air flow
Give examples of how husbandry can be used to control viral diseases
Colostrum management
All in - all out policies
Deep cleaning
Isolation
