Sorry to hear about your dog.
I wouldn't worry about the after effects of the mushroom, though. My one cat is spaced out all the time because of a fever he had when we got him as a kitten, and he lives a normal life beyond being spaced out and extremely jumpy. Also, the effects of some mushrooms usually wear off in a year or so (at least the magic ones according to a study), so he might eventually get back to being normal in time.
I wouldn't worry about the after effects of the mushroom, though. My one cat is spaced out all the time because of a fever he had when we got him as a kitten, and he lives a normal life beyond being spaced out and extremely jumpy. Also, the effects of some mushrooms usually wear off in a year or so (at least the magic ones according to a study), so he might eventually get back to being normal in time.