Murray Leinster's "The Extra Intelligence" (short story, body snatching, free): Something evil is looking for a brain it can take control of
They not only are successful in reviving the dog, for a short while, but the revived dog is behaving as if it's very smart - smarter than a man, in fact. But the woman assistant has observed something the men didn't - dog's intelligence is probably not dog's own...
Mad scientist will later try the procedure on himself, in the hope that he will become an intellectual superman - kill himself & set up the circumstances so friend is forced to try reviving him. Only the woman's theory is right...
Fact sheet.First published: Argosy Weekly, 30 November 1935.
Download full text as part of the scans of the magazine it originally appeared in, or read online at UNZ (UNZ site seems to have some way to download pdf too but I could not get it to work).
Related: Stories of Murray Leinster.