Changes

'''Subacute''' disease causes calves to be depressed, anorexic and ataxic and suppresses [[Rumen - Anatomy & Physiology#Ruminoreticular contraction|rumenal motility]]. The '''dyspnoea is more pronounced than in acute infection due to the longer disease course''' and is almost always fatal. Those that recover become latent carriers.  

'''Subacute''' disease causes calves to be depressed, anorexic and ataxic and suppresses [[Rumen - Anatomy & Physiology#Ruminoreticular contraction|rumenal motility]]. The '''dyspnoea is more pronounced than in acute infection due to the longer disease course''' and is almost always fatal. Those that recover become latent carriers.  

Calves that acquire infection '''after vaccination for BHV-1 and those that have been previously infected''' by either virus become '''silently infected and the virus becomes latent'''. Sites of latency include the '''CNS and mucosae of the nose and trachea'''. The virus can then recrudesce with stress and/or immunosuppression, but usually produces '''no clinical signs'''; it is however shed into the nasal secretions providing a source of infection.  

Calves that acquire infection '''after vaccination for BHV-1 and those that have been previously infected''' by either virus become '''silently infected and the virus becomes latent'''. Sites of latency include the trigeminal ganglia of the '''CNS and mucosae of the nose and trachea'''. The virus can then recrudesce with stress and/or immunosuppression, but usually produces '''no clinical signs'''; it is however shed into the nasal secretions providing a source of infection.

==Diagnosis==

==Diagnosis==