Handy Hint 4 - Recognise Respiratory Symptoms Early by Dr John Kohnke

It is important to recognise the symptoms of EHV before the virus multiplies
within the throat lining and tonsil cells and ‘breaks’ out to be inhaled with the
airstream during exercise into the lower airways.
The normal incubation period is from 4-7 days before an infected horse develops external symptoms of a ‘runny nose’ or a cough when exercising.
The earliest signs within the first 36-48 hours after infection include a slight loss of appetite, reduced ability to exercise, depression and an increased early morning before work (or evening) body temperature above 38.4-39°C.
Stopping exercise and resting the horse in this initial early stage can help the immune system ‘fight’ the virus and reduce its multiplication within the nasal and throat lining cells.
This will help limit numbers of infective viral particles inhaled into the lower airways
to establish lower airway disease, which can result in long term secondary
bacterial infection and reduced respiratory function, necessitating expensive antibiotic and supportive therapy with extended downtime from training.

Article courtesy of Dr John Kohnke BVSc RDA - Talking Horses newsletter