It's normal but I get much bigger handfuls of fur when mine blow their coat and they always are shedding some. Is it warm where you live? Just watch that he isn't getting overheated from the heat. The fever has nothing to do with the shedding. A for shedding "season" mine tend to shed at different times.
not to worry. shedding, shedding, shedding is normal, normal, normal in the corgi world
No idea if it's connected to the fever but that is pretty standard for corgi shedding. You can literally pull fistfulls out of my cardigan.