In recent years, there is a tendency to increase the incidence of the disease in dogs with signs of diarrhea, not only in Ukraine, but also in Europe. In general, diseases with the manifestation of such specific clinical sign as diarrhea can be caused by viruses, bacteria and helminths. In general pathology of dogs, enterovirus infections of puppies occupy a leading place. The practice of specific prophylaxis suggests that in the etiological aspect diseases emerging with this symptom can be caused not only by parvo-, but also corona- and rotavirus enteritis. These diseases are extremely dangerous for puppies and miniature dogs, due to rapid dehydration, and as a result, death.The article presents the results of a study on histological changes in organs and tissues of dogs with coronavirus infection. A histological study of pathological material sampled from 6 dogs of various breeds and sex, aged from 2 to 6 months, died from diarrheal syndrome was carried out. The presence of the coronavirus was confirmed in fecal samples by polymerase chain reaction.The most expressed injuries and typical changes in all dead dogs we recorded in the small intestine, namely in the jejunum and ileum, regional lymph nodes, and also in the spleen.Morphological manifestations of coronavirus infection in dogs at macroscopic level are the following signs: the presence of exudative inflammation in the small intestine in form of serous-fibrinous jejunoileitis, hyperplasia and serohemorrhagic lymphadenitis of the mesenteric lymph nodes, multiple foci of hemorrhage in the parenchyma of the spleen and serous membrane of the small intestine, passive venous hyperemia of the liver and kidneys, dilatation of the right ventricle of the heart, pulmonary edema, cachexia and dehydration of the body.At the microscopic level we registered the following: serofibrinous jejunoileitis, hyperplasia of the lymphoid nodules of the spleen and lymph nodes, hemorrhagic infarctions in the spleen, hyperplasia of individual and aggregated lymphoid nodules of the mucous membrane in the small intestine, degenerative processes in the parenchyma of the liver and kidneys.