Yes you can give cortisone during the injection. It helps the first days a lot.
Some of vets might think cortisone becouse it kill imunity. Yes that’s truly right.
But when the FIP virus Fight in the cats Body It is really necassary that the immune system is a little bit lazy.
That’s why it is dangerous to use medicine that push the Immunsystem.
So cortisone calms down for a while. That’s for the FIP virus at beginning ok.