We love to see pictures of these sorts of things to help give you an opinion. Are you seeing other symptoms, such as nasal drainage, cough or sneeze, wheezing, or gasping? A swollen eyelid with foam or pus, can be a sign of a respiratory disease such as MG or coryza, but without any other symptoms, might be a result of an infection in the eye from dirt or a foreign body, or an insect bite. Clean the eye drainage with saline, and try to get some Terramycin eye ointment or Vetericyn eye gel from a feed store to put into the eye twice a day. If a respiratory disease is suspected, in addition to cleaning the eye, you can get Tylan 50 injectable to give ORALLY twice a day 0.2 ml per pound of weight.