If there is a smell, it sounds like Infectious Coryza. Infectious Coryza is a bacterial infection of poultry, affecting all different species of birds. Infectious Coryza is known for it’s foul rotten smelly cheesy-like smell that comes from the face, mouth or nares, followed by thick harden pus to form in the sinus cavities and around one or both eyes, creating a “swollen bulging like eye”. Infectious Coryza infected birds may or may not have thick sticky yellowish colored discharge from the nares or eyes. This disease is most commonly given by being exposed to new carrier birds. Infectious Coryza is a lifelong permanent chronic disease meaning- that you can treat and have the symptoms go away, but whenever the bird gets stressed again, the symptoms will resurface whenever birds happen to become stressed. All “recovered” like birds, remain permanent lifetime long carriers of the Infectious Coryza bacteria, spreading and shedding it through their feces, feathers, dander, respiratory secretions and other bodily fluids. This is a permanent lifetime disease of poultry and is incurable, but treatable. This is a serious permanent lifetime disease of poultry and is incurable, but treatable with antibiotics. Since Infectious Coryza is caused by a bacteria, antibiotics can help keep symptoms at bay until the symptoms resurface whenever birds become stressed again. Keep in mind that over-use and/or misuse of antibiotics also creates antibiotic-resistant bacteria, making the disease harder to treat than before. It’s critical in any livestock animal, especially poultry, to get any sick or symptomatic birds tested to find out which specific disease they have as soon as possible. That being said, most choose to cull all birds, disinfect and start over fresh. If you’d rather not, then the other option is to keep a closed flock- no new birds into your flock and no birds leave your sick flock. If you choose to start over, always quarantine any new birds that you decide to bring into your flock, 30 day quarantine isn’t always enough, therefore, it’s best to do a 60 day quarantine AWAY from your healthy birds, in another area.
Here’s more information about Infectious Coryza:
https://www.thepoultrysite.com/disease-guide/infectious-coryza
https://tvmdl.tamu.edu/2019/11/25/infectious-coryza-in-chickens/
https://www.canr.msu.edu/news/infectious-coryza-could-be-a-concern-for-poultry-owners
https://poultry.extension.org/artic...oultry-diseases/infectious-coryza-in-poultry/
https://extension.umd.edu/sites/ext...ous Coryza Fact Sheet _NT-edit_01.14.2020.pdf
https://barnhealth.com/features/web/index.php/front/disorder/view?id=285
I hope this helps! Good luck!