I would begin treatment with Tylan 200.
Here is what is recommended from Hopkins Livestock page (you can inject at base of neck between shoulders instead of muscle):
Tylan 200 for cattle. Tylan 200 has proven to be an excellent antibiotic for peafowl.
Tylan 200 is especially affective for treating peafowl with swollen eye sinuses.
Tylan 200 is an intramuscular injection.
1-2 cc as a shot in the leg or the breast muscle for birds over 1 year old.
½-1 cc as a shot in the leg or the breast muscle for birds under 1 year old.
http://hopkinslivestock.com/Peafowl Medications.htm
I'm no expert, but I hope this helps.
Here is what is recommended from Hopkins Livestock page (you can inject at base of neck between shoulders instead of muscle):
Tylan 200 for cattle. Tylan 200 has proven to be an excellent antibiotic for peafowl.
Tylan 200 is especially affective for treating peafowl with swollen eye sinuses.
Tylan 200 is an intramuscular injection.
1-2 cc as a shot in the leg or the breast muscle for birds over 1 year old.
½-1 cc as a shot in the leg or the breast muscle for birds under 1 year old.
http://hopkinslivestock.com/Peafowl Medications.htm
I'm no expert, but I hope this helps.