Seems like there have been quite a few birds with sinus infections, so I thought I start a thread for people to share how they have dealt with them.
I'll start with mine... Last month I found a rooster with a nasty infected eye, but no other signs of respiratory infection, so I removed the pus as best as I could and set him free. Several days later the pus was back, so I did it again, but this time I was more aggressive and manged to get this out of his choanal slit:

Cause of sinus infection was the foxtail. To get it out I had to apply pressure to the area between his nostril and his eye.
This is a choanal slit - Photo by BYC's Nambroth

-Kathy
Edited to add:
No antibiotics were given.
I'll start with mine... Last month I found a rooster with a nasty infected eye, but no other signs of respiratory infection, so I removed the pus as best as I could and set him free. Several days later the pus was back, so I did it again, but this time I was more aggressive and manged to get this out of his choanal slit:
Cause of sinus infection was the foxtail. To get it out I had to apply pressure to the area between his nostril and his eye.
This is a choanal slit - Photo by BYC's Nambroth
-Kathy
Edited to add:
No antibiotics were given.
Last edited: