First of all this does sound like a pup that might be having some sudden pain
Def just relate this to your vet and have the dog checked .... if just for your own piece of mind
as for the spirit world ... yes I do agree that dogs are much more sensitive than we are but there is much more on this earth that affects dogs than elsewhere
I once lived in a house where there were spirits ... a true haunted house
Every once in a while our pug dog would wake up and stand at the end of a hallway where our bedrooms were
at the other end of the hall was a set of stairs
and she would bark and bark until we calmed her down
sometimes the hair on her back would come up and she'd back up as if something was coming toward her
That wasn't the only thing that happened there
but the only thing that involved a dog
