Dissertation for obtaining the educational and scientific degree of Doctor of Philosophy in the field of knowledge 21 "Veterinary Medicine" in the specialty 211 "Veterinary Medicine". – Sumy National Agrarian University, Sumy, 2023. The dissertation is devoted to issues of epizootology, clinical manifestation, diagnosis and treatment of domestic cats suffering from intestinal yersiniosis.
5 The presented work contains modern data on epizootology, features of infection and the course of the disease depending on age, sex, breed, living conditions for intestinal yersiniosis of domestic cats in the territory of Seversky
region.
According to the results of the conducted microbiological studies, it was
established that 180 samples of feces of cats of different age, sex, and breed are infected with Y. enterocolitica. Thanks to the conducted serological research, 107 positive blood serum samples of cats from different cities of Severshchyna were found with three antigens of Y. enterocolitica. The largest number of positive reactions was detected with yersiniosis antigen O:3 - 65.4%, with antigen O:9 - 7 (26.9%), O:6.30 (2.6%), a simultaneous positive reaction was also established in combinations of antigens O:3 and O:6.30 in 6% of cases and a combination of O:3 and O:9 in the agglutination reaction in 13 cases.
During the study of antibody titers, the maximum titers to yersinia antigens were found to be O:3, O:6.30, O:9. The maximum titers with antigen O:3 were detected with a titer of 1:400 ̶ 14.9% and 1:800 ̶ 7.5%. With antigen O:9, antibody titers of 1:400 were recorded in 4 cases, and 1:800 in two cases, whereas with antigen O:6.30, titers of 1:400 and 1:800 were detected in 3.8% of the studied samples.
We found several cases of associated course of panleukopenia and intestinal yersiniosis. Thanks to their research, we managed to determine the dependence of the course of yersinia infection in cats on the mono- and associated course. And also with single and combined infection. The diagnosis of mixed infection was made comprehensively by means of general clinical and laboratory studies, the use of an express test system for panleukopenia, and the establishment of RNGA with specific yersiniosis antigens. The causative agent of intestinal yersiniosis Y.enterocolitica O:9 (with an antibody titer of 1:400) was isolated. Its biological properties were determined and its antimicrobial sensitivity was determined, taking into account which therapy was prescribed.
6 The results of hematological and biochemical studies for intestinal yersiniosis are not very informative and cannot be used as diagnostic markers of yersiniosis
infection.
Pathological-anatomical changes during spontaneous intestinal yersiniosis in
cats were found mainly in the small intestine and in isolated cases in the stomach and large intestine, as well as in the liver, kidneys, spleen, and lungs. They were characterized by dystrophic and stagnant processes in the liver (80%) and lungs (20%), as well as pericarditis. Less often, changes in the kidneys (dystrophic processes in 50% of cases), heart (granular dystrophy - 50%), lungs and spleen (congestive hyperemia - 40% of cases).
The histological picture of changes in the spleen was ambiguous: in the first case, it was characterized by a significant increase in the number of secondary lymph nodes with large reactive centers, and in the other case, on the contrary, it was characterized by delymphotization of the white pulp, a decrease in the number of periarterial lymphoid cuffs. The development of hemorrhagic diathesis and stagnant hyperemia were recorded in the kidneys.
Abortions of fetuses that did not correspond to the stages of development and were not fully formed were recorded in two animals.
The effectiveness of the proposed treatment protocol was tested on 12 animals with a confirmed diagnosis of "intestinal yersiniosis". The animals were conventionally divided into two groups of 6 heads each.
The proposed protocol was used to treat the animals of the first group, and the animals of the second group were treated according to the generally accepted empirical protocol used for gastrointestinal infections.
The assessment of therapeutic effectiveness was determined by the disappearance of clinical signs inherent in this disease, and by checking the release of the causative agent into the environment. Disappearance of clinical signs in the control group of cats was recorded for 6 days, and in the experimental group for 3.5 days. The cessation of pathogen release in animals of the control group stopped on
7 average on the 12th day of treatment, and in the experimental group, in the vast
majority, on the ninth.
Key words: cats, small pets, intestinal yersiniosis, yersiniosis infection, infectious diseases, bacteriology, Y.enterocolitica, pathoanatomical and pathomorphological changes, sensitivity to antibiotics, therapy, probiotics.
