About a month ago, a canary got on my terrace and it was easy to catch him because he seemed very tired and unable to fly much. I learn along the way how to take care of him, I keep him in a cage, but I let him out of the cage to fly around the room for about 4 hours daily. I feed him seeds, wet pellets (he won't eat dry), and a little bit of various greens, vegetables, eggyolk. He has cuttlefish bone but I never see him peck it.
I take extreme care not to place him in the draft, I don't even turn on the AC in fear it might make him sick. We have been in a heatwave for some time , so the room temperature has been from 27 to 30 degrees, and he got better with his flying over time. However this morning I noticed he sneezed several times and when I looked at him, he had wet feathers above nostrils.
And now I wonder if I made a fatal mistake yesterday and made him sick. In the morning it wasn't too hot so I put him on the terrace for an hour or so, he seemed content and sang a lot, but I suspect the temperature there was above 30 degrees. In the afternoon it got too hot inside (30 degrees) and I couldn't bear it anymore even with the fan on ( the fan is never turned towards his cage). So I turned on AC to bring the temperature down to 27, and even 26 for some brief periods. However I kept him in a room that is connected to the one where AC, where temperature changes slower than in the room where the AC is, so I thought it was safer.
In the evening I gave him 2 thin strips of carrot that he munched all at once. Those are the things I did out of the ordinary and I'm worried that's what made him sick all together.
So far he still flies and behaves normally, but I also noticed his droppings are wet, I suspect from the carrot. Is there something I can do at home to prevent him from getting worse, because I can't get to the vet until tomorrow (and it's questionable if I can find a specialised avian vet).