Aim of the study: to examine the pathological changes in dogs that died due to confirmed intestinal yersiniosis and parvoviral enteritis and establish trends for characteristic organ lesions for both diseases in comparison, then evaluate our findings with the existing published material of sufficient evidence quality regarding differential postmortem diagnosis of spontaneous intestinal yersiniosis and parvoviral enteritis in dogs.
 Materials and methods: the study examined the cases of 25 dogs from 2 month to 1.3 y.o. of various breed, gender that died due to either confirmed Canine parvoviral enteritis (CPV) infection or intestinal yersiniosis and subsequently divided into two groups based on their diagnosis.
 The definitive diagnosis has been confirmed by performing rapid ELISA diagnostics (SensPERT®, VetAll Laboratories, Kyunggi-Do, Korea) for CPV and serological tests for Y. enterocolitica sera AT were performed using yersiniosis antigens from the "Component set for serological diagnosis of animal yersiniosis" (Kharkiv, NSC IEKVM, TS 46.15.091-95) in accordance with the "Interim guidelines for the use of a set of components for serological diagnostics". A dilution of 1: 200 has been considered as the diagnostic titer.
 After the definitive diagnosis had been confirmed, the animals were divided into two groups, depending on diagnosis: CPV (n=14) or IY (n=11). The autopsies of twenty randomly (10 from each group) selected dog corpses have been conducted utilizing standard methodology.
 Results: according to the results of autopsy of dogs afflicted by CPV, the main pathological changes were found in the small intestine – catarrhal-desquamative inflammation (in 100 % of cases), serous-hemorrhagic mesenteric lymphadenitis (90 %) large intestine (70 %) in the stomach (60 %), in the liver (50 %), in other organs – less than 40 percent of cases and most notably caused lung damage (edema and local atelectasis) in 90 % of the animals in the study, which was not the case for intestinal yersiniosis with only 20 % incidence of lung damage.
 Conclusions: Spontaneous intestinal yersiniosis in dogs was pathologically manifested by pronounced catarrhal-desquamative processes mainly in the stomach and small intestine (70, 100 and 80 % of cases, respectively), inflammation of the mesenteric lymph nodes (90 %) and large intestine (80 %), dystrophy and congestive processes in the liver (80 %). Low incidence and type of lung damage (congestive hyperemia in 20 % of reviewed cases compared to 90 % of local atelectasis add edema in CPV group) was noteworthy. Cases of 25 animals that died due to either confirmed CPV or Y. enterocolitica infection were analyzed, and 20 animal corpses were autopsied during study. Dogs that died from intestinal yersiniosis had significantly higher frequency of pathological findings in kidney (200 %) and liver (60 %) in particular. Changes in stomach and large intestine were also more frequent. At the same time, we observed a lower frequency of pathological changes in spleen (33 % lower), heart (25 % lower) and the lowest frequency was in lungs (77 % lower) presented by edema and local atelectasis in animals afflicted by yersiniosis compared to CPV. Incidence and manifestation of pathological findings was mesenteric lymph nodes and abdominal cavity were similar, and could not be considered during posthumous diagnostics.