So how is your Horse?
If the temperature is over 101.5 get a VET.
All immune shots given ? Eating its feed , CLEAN hay , off of the ground ?
Does your horse's EYE's run with fluid and is it clear or yellow ?
Nose runny , clear or yellowish ?
Ask your Vet to drain his sinus / eye area / thru the tear ducts inside the nose with simple saline solution..........Fresh air , clean and dry home for your horse .
How old is your horse?
Yes it is great to be able to treat your own horse , and I agree with your two other posters, contact your VET, this is how YOU LEARN........
Best to you and your Horse!