
In the Soviet film adaptation of Heart of a Dog directed by Bortko (1988), Professor Preobrazhensky and his assistant are portrayed as victims of the socialist system.
In Lattuada’s version, on the contrary, they are the creators of a super-idea—one that later gave rise to German Nazism (and to a lesser extent Italian fascism and American ultra-capitalism): eugenics, used as a tool to "improve the breed" of humanity. Both characters also embody extreme social Darwinism.
Sharikov, meanwhile, is portrayed as a noble savage (even in appearance—unlike the Soviet version’s narrow-minded, ape-like Sharikov). His actions are often wild but always innocent and natural. His true misfortunes come from living among a cruel, perverse bourgeoisie, from whom he picks up rotten prejudices, despite the educational efforts of Shvonder.
Shvonder is depicted as a fanatical communist, an ascetic, and in some ways a tragic figure—caught between an evolving, bureaucratic upper echelon (which protects Preobrazhensky) and the bourgeoisie who hate him.
An important detail: Lattuada strayed from depicting Shvonder as a caricatured Jew, as he was deliberately described in Bulgakov’s original novella.