The purpose of the research is to study pathology findings in heterakidosis in broilers.Materials and methods. The study used pathological material (cecum, liver) from 8 laying hens aged one year. Organ samples were delivered to the Pathology Sector in 10% buffered formalin. They were fixed for 36 hours and examined histologically using paraffin embedding. Semi-automatic Thermo Scientific equipment was used to process tissue samples. Histologic specimens were stained with hematoxylin and eosin. The specimen histoarchitecture was assessed with an Axio A1.0 microscope; photographs were taken using the AxioVision software.Results and discussion. Visual assessment of the pathological material revealed thickening of the distal cecum while the liver samples had no signs of pathology. It was found that Heterakis spp. was about 1 cm long; helminth eggs were oval-shaped and had a strong, uniform shell; their size was 49 × 26 micrometers in the mean. When dwelling in the cecum, Heterakis spp. causes atony of the distal cecum wall, and development of inflammatory and necrotic processes in the intestinal mucosa, which promotes active growth of bacterial flora, accumulation of bacterial byproducts and intoxication. In places where the helminth is localized, eggs accumulate and a risk of Histomonas spp. infection increases, namely, amoebic (in the intestinal lumen) and spherical (in the intestinal mucosa) forms of the protozoan were identified. It was not possible to differentiate Histomonas spp. in assessing the histological specimens of the liver from the infected birds. In diagnostics, we should consider the great similarity of morphological characteristics of Heterakis spp. and Ascaridia spp. eggs.

The purpose of the research is localization and morphometry of sarcocysts in animals.Materials and methods. Samples of striated muscle tissue of cows and wild boars were studied to determine the infection intensity and prevalence and determine morphometric parameters of cysts. Pathological material was collected to 10 % buffered formalin solution. For histological examination, muscle tissue samples were taken from the abdominal wall and cardiac muscle. To process tissue samples, paraffin coating was used in semi-automatic equipment from Thermo Scientific. Histological specimens were stained with hematoxylin and eosin and by Mallouri. The specimen histoarchitecture was assessed using an Axio A1.0 microscope; photographs were taken with AxioVision.Results and discussion. The sarcocyst infection prevalence was 60% in cattle and 100% in the boars, with the infection intensity of 1-2 and 2-4 sarcocysts in one FOV, respectively. It was found that the cyst formed a capsule in infected boars with a thickness of 2.6±0.28 μm, while it was practically invisible in cattle, and grouped loose connective tissue fibers were observed around the cyst. The infection intensity can be assessed as low in the studied animals; however, even single parasite cysts entered the human body contribute to sarcocystosis.

The article presents data creation of the DNA probe labeled with fluorescein-12-dUTP for its subsequent use in in-situ hybridization in cryotomic histological sections from samples of internal organs of pigs. This diagnostic method is especially relevant for the inapparate course of infection, which contributes to maintaining the viral load inside the herd without showing pronounced clinical signs. In addition, the method helps to identify the viral genetic material in the pathological samples during the post-viremia period. In this article the stages of creating a probe consisting of 173 pairs of nucleotide bases corresponding to the site of the glycoprotein E2 gene of the classical swine fever virus are shown. The final DNA probe was tested on tonsils from pigs infected with the CSF virus as a positive control for the DNA probe and as a negative control for the DNA probe is tonsils from healthy pigs not vaccinated against CSF were used. Finally, we obtained positive results of using the DNA probe, reflecting its high specificity and selectivity in the studied samples of positive control. The data obtained by us formed the basis for our further research in the field of infectious pathology of farm animals.

Relevance. Currently, the pathology of the joints in broiler chickens remains relevant, especially when the bird is actively growing and gaining weight. Despite the many antibacterial drugs, the results of treatment do not always give a positive effect. This may be due to the properties of the pathogens themselves, which have adapted to resist antibiotics, including the formation of biofilms, limited penetration of the drug into the site of infection, which leads to a decrease in the optimal concentration of the active substance at the site of the pathological process.Methodology. The production experiment was carried out at a poultry farm for the production of poultry meat with cage keeping of broiler chickens of the Соbb 500 cross. In the phase of active growth of broiler chickens, based on clinical, laboratory and histological studies of previous batches of growing broiler chickens, «Spelink®-660» was introduced into the treatment regimen for a new batch of poultry.Results. Production experience has shown that the consistent introduction of the drug with the active ingredient enrofloxacin, colistin sulfate and «Spelink®-660» into the treatment regimen for broiler chickens in the first decade of growing allowed to achieve the best zootechnical indicators and reduce the mortality of birds during the fattening period due to joint pathology.

Prion diseases are infectious neurodegenerative diseases affecting humans and animals that are invariably fatal and have no currently available prevention or treatment methods. These diseases are also known as transmissible spongiform encephalopathies (TSE), characterized by similar neurological disorders, vacuolization of the neuroparenchyma, accumulation of the pathogenic isoform of the prion protein in it, the absence of an immunological response to the pathogen, and the inevitable death. The most famous of them is the classic bovine spongiform encephalopathy, because. has unprecedented social and economic consequences. C-BSE of cattle is also dangerous for humans, causing one of the forms of Creutzfeldt-Jakob disease, leading to a gradual progression of irreversible C-BSE lesions, leading to the death of a sick person. Laboratory animal models make a huge contribution to the study of the biological properties of prions and the diseases they cause. Thus, mouse models of prion infections have played a major role in deciphering fundamental questions of prion biology and assessing the potential transmissibility of neurodegenerative diseases. However, despite the economic acceptability and other positive properties of this model, it has a number of disadvantages. It produces low-volume tissue samples, and it is very difficult to obtain the required volume of serum and cerebrospinal fluid for many studies. Therefore, the search for and study of the disease in new models of laboratory animals sensitive to bovine C-BSE is of great scientific importance in the study of prion diseases. This work shows that during experimental intracerebral infection of guinea pigs with the causative agent of classical bovine spongiform encephalopathy, they are 100% sensitive to the pathogen. The clinical picture of the disease, developing severe pathomorphological changes in all parts of the brain with vacuolization of neurons and neropil and massive deposition of the prion protein PrPSc are described. Guinea pigs can be a highly sensitive object for laboratory study of the causative agent of bovine spongiform encephalopathy.

The purpose of the research is to evaluate the parasitism effects on clinical parameters of laboratory animals.Materials and methods. The venous blood of 20 rabbits aged 1 year was taken to perform biochemical and general blood tests, for which purpose hematological analyzers were used. The animals were dissected using the Shor’s method. The topography of the organ complex was evaluated, and pathological material was collected and placed to 10% buffered formalin. For pathomorphological examination, liver, spleen, lung, and kidney samples were taken. To determine the histological pattern, paraffin-embedded samples on Thermo Scientific semi-automatic equipment were used. Histologic specimens were stained with hematoxylin and eosin. The histoarchitecture of the specimens was evaluated using an Axio A1.0 microscope, and photography was conducted with the AxioVision software.Results and discussion. The article presents the data of the general and biochemical blood tests of the blood from the rabbits intended to be used in the experiment. Further, the pathoanatomical picture of the liver was shown in animals infected with Eimeria spp., and the histological pattern was presented for parenchymal organs. We found that the main biochemical values that exceeded reference values were liver values, namely, aspartate aminotransferase and alanine aminotransferase. We also observed an increase in monocytes and granulocytes in the blood. Pathological and anatomical changes were only expressed in the liver, while no changes in the macro pattern were observed in other organs. Histological examination of parenchymal organs showed a significant pathology in the liver due to endogenous stages of oocysts occurred in its structure. Additionally, we observed a strong eosinophil response in the spleen and a high content of eosinophils in the pulmonary veins.

Experiments have shown that guinea pigs, when experimentally infected with the causative agent C-BSE of cattle, can be a highly sensitive object for laboratory study of the causative agent of spongiform encephalopathy of cows.

Experiments have shown that strain BT-91 in sheep causes clinical symptoms of the disease and histopathological changes in the central nervous system that are characteristic of classical scrapie.

The article presents experimental data on the reproduction of classical swine fever and the development of immunohistochemical method for the study of the obtained pathological material. 2 groups of animals were involved in the experiment (experimental infection group and non-control). During the experiment, blood was taken to obtain serum for further study, as well as organs for histological (paraffin embedded samples) examination and observation of organ pathology and native samples (frozen slices) for testing them in an immunohistochemical reaction. For indirect immunohistochemical reaction, primary mouse monoclonal antibodies specific to the recombinant protein E2 of the classical swine fever virus and secondary goat antibodies to mouse immunoglobulin labeled with horseradish peroxidase were used. Histological examination of the palatine tonsil, kidneys, spleen, liver, lung, lymph nodes and spinal cord brain revealed the development of pathological in all samples from the experimental infection group. The use of the ELISA method confirmed seroconversion of inoculated animals from the experimental infection group by the end of the study (DPI 14). Also, PCR studies have shown viremia in the same animals starting from the 2nd day of the experiment and up to the date of euthanasia of the animals at the end of the experiment, which corresponds to 14 days after infection. Despite the pathological changes in all the organs we studied, the indirect immunohistochemical method showed a positive result only in the spleen and in the palatine tonsil, while the number of positive sites was greater in the spleen. The nature of the chromogen distribution indicated the presence of the CSF virus antigen in the red pulp of the spleen, in leukocyte cells. The data obtained by us in the immunohistochemical reaction correlate with the data obtained in ELISA and PCR in the study of blood sera.

The influence of iodine-containing radiopaque substances (water-soluble and water-insoluble compounds) nature on the functional properties of the emboli was studied in a comparative aspect during the experiment in vivo. The assessment was carried out through radiographic, histological, hematological and microscopic research techniques. It has been found that emboli, regardless of the radiopaque substance nature, completely block the blood flow and do not have a toxic effect on the organism. Contrasting of liquid embolizing systems with contrasting substances of different nature leads to some differences, however, the embolizing properties of the systems are preserved.

A composition in the form of liquid polymer substance intended for embolization procedures was studied in in vivo experiment. The preparation was injected to rabbits into the femoral artery and abdominal aorta. The polymer composition exhibited properties previously demonstrated in vitro: strong adhesion to the vascular wall, high plasticity sufficient for embolization of the blood vessels, distal distribution, and the absence of toxic effects. The contrast substance remained in the embolus, which simplified its further localization. The agent underwent nether resorption nor organization. Injection of the agent in a volume of 0.1 ml was sufficient for embolization of an artery with a diameter of 0.1 cm. The polymer composition completely obstructed the vessel without inducing perforation of its wall. During the first day of the experiment, a slight infiltration of surrounding tissues with lymphoid cells was observed. By day 7, total dry necrosis of pelvic limb distal to the injection site was diagnosed. Inflammation of the surrounding tissues was shown histologically and was considered as the body response to impaired circulation and necrosis.