SJchickens
Songster
Not likely that both would have neurological issues. Upper respiratory symptoms can be very mild to quite severe and anywhere in between. Sinus issues can lead to them having cheesy plugs in their ears and they will head shake in an attempt to dislodge them. Check the nares for plugs also.
If it is a sinus issue, how do I detect it and or treat it? I checked the ears of the polish and found nothing unusual. Not sure what to do besides that. I'll check their nares.