This is a blockage of the oesophagus with food materials. Saliva and food can be seen at nostrils and horse is usually distressed and coughing.

What to do:    
  •  Take away all food and water 
  • Keep horse quiet and relaxed  
  • Massage neck in a downward motion  
  • Blockage may pass on its own without any intervention              
  • Call vet for advice