Veterinary Virology

Clinical presentation

Diagnosis

Molecular characteristics

Treatment

Disease control

Lilly – 8 week old beagle x spaniel

Diagnostic tests

Canine parvovirus

ssDNA virus, 5000 nucleotides

Non enveloped

Discovered in late 1970s

Replicates in rapidly dividing cells intestinal cells - enteritis lymphoid cells - panleukopaenia

Treatment of canine parvovirus

IVFTAntibioticsAnalgesiaGastroprotectantsAnti-emetics

Prevention

Vaccination Parvovirus Canine adenovirus 1+2 Distemper Parainfluenza virus (Leptospirosis) (Coronavirus) (Rabies)

Isolation – strict biosecurity

Bobby, 2 year old MN rabbit

Myxomatosis

Classic clinical signs

• Swelling of eyelids with ocular discharge

• Swellings around nose and base of ear

• Swollen genitalia

• Very lethargic and inappatent

Virus characteristics

Pox virus, ‘myxoma virus’

Enveloped, dsDNA, 162,000nt genome

Avoids recognition by immune system - produce proteins that mimic host cell receptors and cytokines

Discovered in 1896, Uruguay

Benign infection in South American rabbits, but fatal disease in European rabbit Oryctalagus cuniculus

Treatment and control

• No known treatment. 95% die of infection within a few days

• Vaccination • Every 6 months• Viral haemorrhagic

disease virus

Hill Farm, 60 head beef cattle, 400 sheep

Foot and Mouth virus (FMDV)

• Picornavirus

• +ve ssRNA, non enveloped, 8.4Kbp genome

• Transmitted by direct contact, fomites and aerosol

• Replicates in epithelium at entry site before inducing viraemia

• Does it kill all hosts?

Control

Cull

Strict biosecurity

Enforced movement bans / quarantine

Vaccination?

Litter of kittens, 6 weeks old

‘Cat Flu’ – FCV, FHV and chlamydophila

Feline calicivirus [FCV]

• ssRNA non enveloped virus

• Numerous strains

• Spread by oro/nasal secretions, direct or fomites

• Can be acute or persistent

• Variable clinical signs whilst shedding

Stomatitis

Feline herpesvirus [FHV]

• dsDNA enveloped virus

• Single strain

• Acute initial infection 2-4wks, then establishes latency in up to 90% cases

• Reactivation can occur after stress

Treatment and control

TLC

Antibiotics

Decongestants

Owner education is important

Vaccination

• FCV

• FHV

• Feline panleukopaenia virus

• Chlamydophila

• FeLV

Harris, ME 5yr old DSH

Investigations

Feline immunodeficiency virus [FIV]

Retrovirus, ssRNA, 9400 nt

Identified in 1986

Transmitted by saliva-blood contact e.g. bites

Initial viraemia, then only low levels of virus for x months before immunodeficiency develops

No recovery from infection occurs but cases can survive a number of years (similar to HIV)

2-3% cats in UK have FIV

Feline immunodeficiency virus [FIV]