No telling. I doubt it has anything to do with herpes because my herpes girl has a nice, strong voice in the morning. Most likely, like humans, it just has to do with morning voice.
Is her herpes virus active when she does this? I'm sure it's like a cold virus and could cause sinus drainage which would give her a sore throat. By active I mean are her eyes runny, does she have nasal discharge? My cats have been MUCH better since I started giving them L-lysine treats when they start to have symptoms of herpes. It builds up their immune systems. It's not very expensive at Amazon, and I get the treats so they take it. Good luck!
WE put her in the bathroom about 12 or 1 in morning when she wakes up, she goes to sleep with us but gets up real early so I put her in our bathroom , which is huge....her litter box , water, bed and toys are in there and the heat is on 73 but the bathroom floor is tile...do you think it's to cold for her in there ?