Heart of a Dog is one of the best examples of Bulgakov's criticisms of life in the Soviet Union. Written when Bulgakov was 33 years old, it was first introduced to the public in March 1925 in a Moscow apartment with a gathering of approximately 50 contemporary intellectuals. Though he had held a similar event the previous year to introduce his novel The Fatal Eggs, he was worried that his sharp satire of the Soviet state could lead to his arrest or worse at the hands of the authorities. This fear turned out to be well-founded: in attendance at the novel's debut was an informant for the Russian state, and after the reading, Bulgakov’s flat was searched. His personal diary and other works, including the novel, were confiscated because of their provocative character. Four years later, around the time that Bulgakov's works were banned by the Soviet state, the manuscript was returned to him. Afterwards, The Heart of a Dog was widely read in samizdat—that is, through secretive and unofficial channels meant to circumvent state censorship. Eventually, the novel was officially released in Russian, but this only occurred in 1987, 47 years after Bulgakov's death.
The novel centers on the dog Sharik, who has been badly treated by humans at the story's beginning. When a professor named Phillip Phillippovich Preobrazhensky offers him food and takes him in, Sharik hardly expects this to be the beginning of a complex relationship. However, soon after Sharik is introduced to the Professor's assistant Dr. Ivan Arnoldovich Bormenthal, he finds out that the professor's interest in him is more than a standard owner-pet fixation. Professor Preobrazhensky uses Sharik as the guinea pig for an experiment—in order to test the rejuvenatory properties of certain organ transplants, Preobrazhensky transplants human testes and a human pituitary gland into Sharik. After the procedure, however, Sharik is transformed into a man—specifically, an ill-mannered and coarse Bolshevik sympathizer. After many offenses against Professor Preobrazhensky, such as destroying the Professor's faucet and attempting to rape one of his domestic servants, Sharik (now named Poligraph Poligraphovich Sharikov) takes up work with the Soviet state, becomes friends with the superintendent of the housing committee, and even finds a trashy woman whom he intends to marry. Professor Preobrazhensky finds all of this unacceptable, and he and Bormenthal plan to get rid of Sharik by returning him to his original, canine state. In the novel's epilogue, when officials appear to inquire about Poligraph Poligraphovich's disappearance, we see that this has, in fact, happened. The novel ends with Sharik once again being obedient and looking on at Professor Preobrazhensky.
The novel is meant to satirize both Bolshevik manners as well as the exaggerated bourgeois affect of Professor Preobrazhensky. It is as much a criticism of the Soviet establishment that enables Sharik as it is of the eugenic fascinations that lead Professor Preobrazhensky to conduct the procedure in the first place. For its richness and value as a social satire, as well as its notable incorporation of the grotesque, the novel is widely read and studied in Eastern Europe. It has been reinterpreted many times, in different languages and media, all over the world—including a musical, many films, and several operas. It also remains the subject of intense critical debate—for example, while some claim that Bulgakov aligns himself with Professor Preobrazhensky, others reject this claim. As another example, while some think that the novel remains unfinished, others contest this claim by pointing to stylistic cues within the text. Despite these debates, however, the novel remains a favorite of Soviet-era literature, and it is a good example of Bulgakov's style and thematic interests.