Bulgakov: A Dog's Heart recap

Professor Preobrazhensky, a privileged surgeon in early Soviet Moscow, rescues a stray dog called Sharik and uses him in an experiment, transplanting organs from the dead criminal Klim Chugunkin. Sharik rapidly changes into a humanlike man who calls himself Polygraph Polygraphovich Sharikov. His coarse behavior, demands for documents and housing, and alliance with the building official Shvonder turn the professor's apartment into a battleground. Sharikov gains a municipal job killing stray animals, deceives a young colleague, and finally reports the professor to the authorities. When he threatens Preobrazhensky and Doctor Bormental with a weapon, the doctors subdue him and reverse the operation. Officials investigating Sharikov's disappearance find no corpse, only a being changing back into a dog. Sharik returns to canine form and lives comfortably with the professor, while the failed attempt to manufacture a person is quietly erased.

A hungry stray dog wanders wintry Moscow after a cook scalds his side. He observes the people passing him with a mixture of fear and shrewd judgment. Professor Philip Philippovich Preobrazhensky wins his confidence with sausage and takes him to a spacious apartment, where the household treats his wound and names him Sharik. The professor is a famous surgeon whose affluent patients seek rejuvenation treatments. His comfort and authority clash with the building committee led by Shvonder, which wants him to give up some of his rooms. Preobrazhensky refuses and uses his connections to preserve the apartment. Well fed and fitted with a collar, Sharik begins to regard the household as a secure new world, though he does not understand why the professor has shown him such generosity.

Sharik settles into the rhythms of Professor Preobrazhensky's household, where patients, elaborate meals, and political arguments reveal a way of life insulated from the shortages outside. His improved appearance and collar change how strangers treat him. The professor and Doctor Bormental then prepare a risky operation. They anesthetize Sharik and transplant into him reproductive organs and a pituitary gland taken from Klim Chugunkin, a recently dead criminal. The procedure is intended as an experiment in rejuvenation, and Sharik nearly dies under the strain. Bormental begins a detailed clinical record as the dog's temperature and body change in unexpected ways.

The experiment produces far more than renewed youth. Sharik loses his fur, stands upright, and develops human speech and features. His first words, manners, and appetites are crude, and the doctors connect many of them to Klim Chugunkin's history. Now physically close to a man, he demands a name and official papers, choosing Polygraph Polygraphovich Sharikov. Shvonder helps him assert legal rights as a resident of the apartment. Professor Preobrazhensky attempts to teach him hygiene, speech, and social conduct, while Sharikov resists instruction and pursues the impulses that interest him. The professor recognizes that the donor's character has not simply disappeared in the transformed body and grows alarmed by the result.

Life with Sharikov becomes increasingly unstable. He drinks, steals, harasses the household, chases cats, and treats the professor's efforts at education with hostility. Shvonder supplies him with political language and encourages his claims against Preobrazhensky. Attempts to impose rules only produce new arguments, and Doctor Bormental increasingly doubts that instruction can correct the result of the operation. Professor Preobrazhensky concludes that replacing the dog's pituitary gland did not elevate Sharik but allowed the donor's worst habits to dominate a new body. Sharikov eventually disappears from the apartment, leaving the household uncertain whether he has fled or is preparing another challenge to the doctors' authority.

Sharikov returns with official employment in a municipal department that removes stray animals and later brings home a young colleague whom he plans to marry. Professor Preobrazhensky exposes the false story Sharikov told her. Sharikov then submits a political denunciation accusing the professor and Doctor Bormental of disloyal conduct, but a well-connected patient warns them. When confronted, Sharikov refuses to leave and draws a revolver. The doctors overpower him and reverse the transplant. Sharikov vanishes as a legal person while his body steadily returns to canine form. Investigators arrive after Shvonder reports a suspected killing, but the professor presents the transforming creature as proof that no murder occurred. Fully restored as a dog, Sharik again lives contentedly in the apartment, with only confused memories of his human existence, while Preobrazhensky resumes his work.

Sharikov returns to the apartment after denouncing Professor Preobrazhensky to the authorities and threatens him and Bormental with a revolver. The doctors overpower him and repeat the operation in reverse, removing the transplanted human material. When investigators arrive to ask about Sharikov's disappearance, the professor shows them a creature visibly changing back into a dog and denies that a murder has occurred. The officials leave without making an arrest. Sharik gradually regains his canine body and contented outlook, remembering the human episode only as a confused discomfort. He remains in the professor's apartment while Preobrazhensky resumes his medical work. The household's old order has been restored by undoing the experiment, although the professor continues procedures whose full meaning the dog cannot understand.