EGS Prognosis

Both AGS and SAGS cases are fatal, with no chance of recovery.  For both these subsets treatment should not be considered.  Chronic grass sickness cases have a 40-60% chance of survival based on careful case selection although it is important to note that not all CGS cases survive. The most useful prognostic indicators are:

In recovering cases the turning point is when weight gain, in contrast to weight loss, occurs.  This is usually 2-5 weeks from the onset of disease.  Survival chances are good if the horse lives 6-8 weeks, with rare relapses.

Several complications may arise in the CGS cases that survive including: diarrhoea, choke and inhalation pneumonia. 

This picture shows a horse displaying ptosis (drooping of the eyelids due to muscle paralysis) which gives the horse a sleepy appearance.  In this horse the black eyelashes on the left side of the horse can be seen to be pointing downwards relative to the white ones on the right side.  This occurs after application of 0.5% phenylephrine drops which act to reverse the eyelid drooping and is used as a simple non-invasive diagnostic test.