I wish someone here could give you a definitive answer, but there's no way we can do that.
All we can do is share what we have read and learned. You're the only who is there with Sunny, and you're only one who can make a decision on how to treat her. Hopefully it is gapeworm and the treatment will work. Did you look over any of the other articles that are located in the link I shared with you? There is another one that sort of fits also. I hate to make you worry, but it's good to read all this stuff, I think.
Found here: http://www.shagbarkbantams.com/page11.htm
Upper Respiratory Fungal Infections
Following damp weather or after drying out damp coop conditions, the molds that were once actively growing lose the dampness they need to live. When they do, they 'sporulate' into mold spores in order to survive for later reproduction. In their mold spore state, they become airborne or stay in litter or sand dust and can be inhaled by our birds. Once inhaled, the spores find a new damp environment in the lungs and trachea of a bird where their growth creates an upper respiratory fungal infection.
Birds that are otherwise strong and healthy can usually fight off a mild infection and recover nicely, although the fungus can remain in the bird and reappear during future events of stress. However, when birds are at their weakest - due to youth, old age, or stressed in some other way - they can die quickly and without noticeable symptoms. Noticeable symptoms include gaping (stretching their neck forward and opening their mouth), coughing, sneezing, sniffling, 'chirping', and gasping for air. Sometimes a bird with no noticeable symptoms can be held to your ear to hear crackling, rattling, and gurgling from inside their lungs when they breathe. (Symptoms are more noticeable in waterfowl than in poultry.) The bird can simply suffocate from the fungus in their trachea, or die from the excess fluid created in their lungs as their bodies try to fight off the invaders.
Found here: http://www.shagbarkbantams.com/page11.htm
Upper Respiratory Fungal Infections
Following damp weather or after drying out damp coop conditions, the molds that were once actively growing lose the dampness they need to live. When they do, they 'sporulate' into mold spores in order to survive for later reproduction. In their mold spore state, they become airborne or stay in litter or sand dust and can be inhaled by our birds. Once inhaled, the spores find a new damp environment in the lungs and trachea of a bird where their growth creates an upper respiratory fungal infection.
Birds that are otherwise strong and healthy can usually fight off a mild infection and recover nicely, although the fungus can remain in the bird and reappear during future events of stress. However, when birds are at their weakest - due to youth, old age, or stressed in some other way - they can die quickly and without noticeable symptoms. Noticeable symptoms include gaping (stretching their neck forward and opening their mouth), coughing, sneezing, sniffling, 'chirping', and gasping for air. Sometimes a bird with no noticeable symptoms can be held to your ear to hear crackling, rattling, and gurgling from inside their lungs when they breathe. (Symptoms are more noticeable in waterfowl than in poultry.) The bird can simply suffocate from the fungus in their trachea, or die from the excess fluid created in their lungs as their bodies try to fight off the invaders.
