Herpesviridae
Introduction
- Bovine herpesvirus - 1 (Infectious bovine rhinotracheitis virus) contributes to undifferentiated neonatal calf diarrhoea, a mixed viral enteritis in calves; and rhinitis
Bovine herpesvirus -1
- Causes Infectious bovine rhinotracheitis (IBR)
- Highly infectious URT disease of cattle
- High morbidity, low mortality
- Aerosol transmission - requires close contact between animals
- BHV-1 infects the respiratory mucosal epithelial cells (intranuclear inclusion eosinophilic inclusion bodies)from nasal mucosa down to bronchioles
- leading to neutrophilic inflammation of varying severity.... serous -> catarrhal -> purulent nasal discharge, sneezing, coughing.
- with secondary bacterial infection (eg: Pasturella spp., Mycoplasma spp., Fusobacterium necrophorum) can lead to fibrinous to necrotizing inflammation; mucosal sloughing, ulceration... pyrexia, dyspnoea ... inhalation pneumonia... death.
- Clinical signs include coughing, discharge, lacrimation, and increased respiratory rate.
- Clinical disease most severe in young calves - can develop mucosal ulcerative lesions in the oesophagus and forestomachs and viraemia with multiorgan infection.
- Cause of abortion >5 months of gestation
- Feline viral rhinotracheitis in rhinitis