Assassin snail acting weird

[lmhicks101]

This snail was buried for over a week I thought it was dead so I pulled up up and put it in the front of the tank. Well a few days ago I moved him and he sucked himself in. I flipped him over the right way so his she was down and he flipped him self back upside down and has been like this.

Does he have a parasite?

I thought he was dead so just treated the tank with no-plunaria. 
nothings bothering him and he has food. He’s sitting right where I drop the frozen food at. 

[Guppysnail]

I have not kept assassins but no planaria is not snail safe. Part of its marketing is to kill snails and snail eggs. You may want to move him to a different tank. Snails do not carry internal parasites the way fish do. They are usually only intermediate hosts. The ones they do get are not normal in the aquarium hobby.