Brian,,don't give up please? After all the varmit problems you have overcome and now this? Did he seem to be energetic before he died? As in did he avoid you or was he just staying and not moving on his perch? I have learned one thing the hard way this winter that I should have paid more attention to and been able to intervene. But all my birds will move to avoid me when I feed and water.If they just sit there and don't move,or stand up on the perch take notice. If they are not on the perch before dark,take notice.
All me breeding birds has been on medication all week here.I'm doing preventive intestinal-internal problems by mixing 1oz per 4 gallons of water using sulfadimethoxine. I started giving this in the water last Wednesday and Saturday-Monday added 3cc per gallon of Safegard. Next Friday I will start the Safegard treatment again for 3 more days and thens it's just Ivemectrin maybe the 3rd week of the month here and I'm done.
Catch your birds and see how much meat is around their breastbone.I've fed a soybean fat into my birds diets all winter just to make sure they had energy to fight the cold and possibly add some weight if necessary.Was your male thin around the breast area? It's hard to tell the true condition of the bird unless you handle them.Feathers hides a lot.