Peer-reviewed journal Russian Journal of Veterinary Pathology
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DAT Knockout Rat Models: Dopamine Dysfunction, Epigenetic Mechanisms, and Approaches to Gene Therapy: A Literature Review
Introduction. Dopamine transporter gene knockout (DAT-KO) animal model is a valuable experimental tool for studying the pathophysiology of diseases associated with dopamine dysfunction, such as attention-deficit/hyperactivity disorder, schizophrenia, and Parkinson’s disease. The aim of the present review is to systematize the scientific data on using the DAT-KO rat models for studying dopaminergic dysfunction, epigenetic mechanisms, and gene therapy approaches. Materials and Methods. Literary sources were searched for in PubMed, Scopus, Web of Science, and Google Scholar scientific citation databases. The original studies (n=49) on the structure and function of DAT, knockout models, epigenetic mechanisms, and gene therapy published from 1991 to 2025 in English language only were included into the review. The results have been presented in a PRISMA flow chart and in the illustrations. Results. DAT knockout rat models exhibit a 5–7-fold increase of extracellular dopamine level, hyperactivity and structural changes in the basal ganglia, which indicates dopamine dysfunction. Homozygous knockout animals are found to completely lack functional DAT protein, whereas animals with heterozygous knockout retain approximately half of its function and exhibit intermediate phenotypes. Epigenetic regulation of SLC6A3 gene expression is mediated by DNA methylation, histone modifications (including H3K9/K14 acetylation and H3K27 methylation) and microRNA modifications. Moreover, the DAT promoter remains hypomethylated during postnatal ontogenesis in rats, resulting in its age-related expression increase. Gene therapy using viral vectors has demonstrated the potential to restore DAT function. Discussion and Conclusion. The DAT-KO rat models reliably reproduce the key neurochemical and morphological features of dopaminergic dysfunction. However, the picture seems much incomplete due to the fragmentary character of data on the dynamics of epigenetic regulation of dopamine transporter expression during disease progression and insufficient evidence base on dose-dependent effects and long-term safety of gene therapy. The epigenetic mechanisms open the new tracks for biomarker search and personalization of therapy. Gene therapy using adeno-associated viral and lentiviral vectors demonstrates the potential to restore DAT function in the preclinical models, however, further clarification on dosedependent effects and minimization of the immune response is required. The integration of epigenetic markers into the clinical protocols, development of combinatory strategies, and validation of the DAT-KO models for comorbid conditions continue to be the promising tracks for further research.
The Relationship between Caspase-3, -6 Expression and Morphological Changes in Kidneys of Cows
Introduction. Cow kidneys are exposed to the impact of industrial factors, which is manifested in development of the various nephropathies with systemic effects on organism. The kidneys are the main organs responsible for homeostasis by regulating osmolarity, mineral balance, and acid-base balance in organism through the excretion of water and inorganic electrolytes. Renal pathology often has latent character and is diagnosed postmortem. Significant destructive changes, including cell death, are often detected in lactating cows due to high metabolic load they undergo. Caspase pathway is one of the pathways in the complex apoptotic signaling cascade. Unfortunately, the expression of caspases in bovine kidneys has not been yet described in the literature. The aim of the study is to describe the relationship between the expression of caspase-3 and caspase-6 and the pathological changes in the kidneys of high-yielding cows. Materials and Methods. A morphological study of renal samples from high-yielding cows (4–6 lactations, 7–8 years old, n=4) was conducted at the Ural Federal Agrarian Scientific Research Center, Ural Branch of the Russian Academy of Sciences in the period from 2023 to 2025. Standard histological techniques including hematoxylin and eosin staining and Mallory’s trichrome staining were used. Immunohistochemical analysis of the samples using antibodies to caspase-3, and -6 was performed. Results. It was found that in the kidneys of 7–8-year-old cows there develop the destructive processes including renal failure, inflammatory reactions, and sclerotic and microcirculatory disorders. The observed conditions are associated with high expression of caspase-6 at the level of the renal tubules, which confirms damage to the renal parenchyma. Caspase-3 is expressed primarily in the renal tubules and in renal stroma elements, which indicates intensification of apoptotic processes across the entire organ. Discussion and Conclusion. The destructive processes revealed in the kidneys of high-yielding cows are likely to be associated not only with the age but also with the high metabolic load imposed on the organism during lactation. The research findings substantiate the need for further study of pro-apoptotic factors due to their influence on the development of various pathologies in cattle.
Optimization of General Anesthesia Monitoring Methods Used in Laboratory Animals during Development and Experimental Study of Veterinary Drugs
Introduction. Giving general anesthesia to animals is an important element of experimental research during the development and study of new veterinary drugs. Due to specific nature of general anesthesia and the need to use the potent sedatives and hypnotics, it has always been posing a risk to laboratory animals. In the frame of present-day veterinary research, the problem of proficient monitoring of anesthesia is extremely relevant, especially with regard to research involving laboratory rodents. The aim of the study is to develop and optimize laboratory monitoring methods of general anesthesia in animals during experimental studies of new veterinary drugs. Materials and Methods. The study was conducted at the research laboratory of the Institute of Living Systems, DSTU, from January to May 2024. The experiment involved 20 Wistar rats of both sexes weighing 300–400 g that were subjected to inhalation anesthesia with isoflurane, using an RWD R520 anesthesia machine. The laboratory monitoring protocols were developed based on the electroencephalography (EEG), electrocardiography (ECG), respiratory rate, blood pressure, and body temperature parameters. The condition of animal organs and systems was assessed by means of biochemical blood and urine tests, as well as excretory function tests. Results. An inhalation chamber connected to an anesthesia machine was designed for the study in rats. It allowed labor-atory monitoring of animals’ condition during inhalation anesthesia by electrophysiological and functional methods. A trial mode of the chamber using 2.0% isoflurane gas supply, at a flow rate of 2.0 l/min, and a withdrawal rate of 8.0 l/min had proved to be the optimal protocol for administering general anesthesia to laboratory rats. Electrophysiological, biochemical, and functional parameters demonstrated high tolerability of the anesthesia protocol used. Discussion and Conclusion. The development proposed by the authors optimizes laboratory monitoring in animals during general anesthesia, contributes to improvement of quality of experimental research results, facilitates the work of re-searchers, and can be used during the development of new veterinary drugs.
Clinical, Echocardiographic and Cytological Characteristics of Pericardial Pathologies Accompanied by Pericardial Effusion in Dogs
Introduction. The majority of pericardial diseases are accompanied by pathological accumulation of fluid in the pericardial cavity (effusion), as well as cardiac tamponade. Physical examination methods combined with transthoracic echocardiography are widely used to diagnose these conditions. An important task for veterinary specialists is to determine characteristic symptoms and specific echocardiographic signs of cardiac tamponade, which is considered to be a life-threatening condition. Cytological examination of pericardial fluid is an integral part in diagnosing the cause of the effusion. A comprehensive approach to diagnosis underpins the efficiency of treatment strategies. The existing studies poorly reveal the relationships between the clinical symptoms and echocardiographic signs, which could enable the diagnosis of disease severity and its prognosis, neither do they fully elucidate the cytological characteristics of effusions that could indicate the causes of effusion occurrence. The aim of the study is to establish the clinical, echocardiographic, and cytological relationships in dogs with pericardial pathologies accompanied by pericardial effusion. Materials and Methods. The study was conducted at the Department of Veterinary Surgery of Moscow State Academy of Veterinary Medicine and Biotechnology – MVA named after K. I. Skryabin and at the Veterinary Research Center “Biocontrol” in the period from 2018 to 2023. The objects under study were dogs of various breeds, ages, and sexes (n=200). The examination methodology included: collection of patient’s medical history, clinical examination, echocardiography, electrocardiography, chest radiography, ultrasonographic visualization of free fluid in the thoracic and abdominal cavities, pericardiocentesis, cytological examination of effusion, and histological examination of pathological material obtained during surgery. Results. During the echocardiography, a ring-shaped anechoic space of varying diameter was revealed around the heart in all the studied dogs with pericardial effusion. Of 200 patients, cardiac tamponade was registered in 64 animals (32.0%), to whom pericardiocentesis was performed. For further determination of the causes of pericardial effusion, cytological examination of the obtained fluid was performed in 61 patients. According to cytomorphological characteristics, the following types of effusion were identified: transudate (1.6%), modified transudate (4.9%), septic exudate (1.6%), hemorrhagic effusion (which, in turn, was divided into effusion corresponding to: acute hemorrhage (4.9%), chronic hemorrhage (77.0%), hemorrhagic effusion with cytological signs of a tumor (9.8%)). Discussion and Conclusion. In the presence of pericardial effusion, detection of the cardiac tamponade syndrome is of great clinical importance. We have established the most common echocardiographic signs of tamponade: caudal vena cava dilation and reduction of its collapsibility amplitude to less than 50%, as well as right atrial collapse. A relationship between the clinical symptoms (abdomen volume increase due to accumulation of ascitic fluid, progressing weakness, and exercise tolerance decrease) and echocardiographic signs of cardiac tamponade was revealed. Based on cytological examination results, the hemorrhagic type of pericardial effusion was identified as the most common one, concomitant to cardiac and pericardial tumors in older dogs of medium and large breeds.
Comparison of the Diagnostic Accuracy of Semiautomated and Expert-Based Calculation of the Vertebral Heart Score in Cats and Dogs: First Stage Validation of the “Desktop Application for Automation of the VHS Calculation Based on Radiographs”
Introduction. Cardiac diseases are considered to be among the main causes of mortality in small domestic animals. Calculation of the vertebral heart score (VHS) is a method used to assess the cardiac silhouette enlargement on radiographs and predict the development of congestive heart failure. However, traditional manual procedure of VHS calculation is characterized by high inter-observer variability, subjectivity, and significant time-consumption. To improve the access to objective cardiac screening in every-day clinical practice, the authors has developed a desktop application for automating VHS calculation using the artificial intelligence (AI) technologies that unifies the assessment standard, minimizes human error, and accelerates processing of radiographs. The aim of the present pilot research is to conduct the first stage validation of the application and compare the diagnostic accuracy of two VHS calculation methods — semiautomated and expert-based. Materials and Methods. A balanced sample of 30 right lateral chest radiographs of dogs and cats was selected for analysis as a result of simple random sampling. Preliminary VHS was calculated by manual measurements on the radiographs by the Buchanan & Bücheler method: two veterinarians specializing in visual diagnostics measured the short and long axes of the heart on the radiographs and then compared their dimensions against the spinal vertebrae. The semi-automated calculation of VHS was performed by the author-developed “Desktop application for automation of the vertebral heart score (VHS) calculation based on radiographs” using a convolutional neural network. App validation implied a comparison of the results of the two methods of VHS calculation, taking into account the intraclass correlation coefficient (ICC). Results. The “Desktop application for automation of the vertebral heart score (VHS) calculation based on radiographs” has proved to perform a highly accurate and replicable automated calculation of VHS on lateral chest radiographs of dogs and cats. It also has demonstrated statistically high agreement with the calculations obtained by veterinarians specializing in visual diagnostics (ICC≥0.97), along with less time required for calculation. Discussion and Conclusion. The first stage of app validation has demonstrated an excellent agreement between the AI and two specialists’ results, therefore, the proposed approach can be deemed a future-oriented tool for general practitioners. The present pilot research has several limitations, i.e. it was conducted on a relatively small sample of animals, which may be insufficient for evaluation of app performance in narrow subgroups (e.g., in specific breeds or in severe cardiomegaly cases). Further studies in larger, more heterogeneous cohorts, including patients with severe cardiomegaly and anatomical abnormalities, are required to confirm clinical significance of the results.
Expression of Vimentin, α-SMA, and CD34 in Malignant Mammary Tumors in Dogs
Introduction. At the contemporary stage of mammary tumor studies, the microenvironment is considered a key factor contributing to neoplasia formation and metastasis. Therefore, the greatest attention is paid to the cellular composition of the mammary tumor microenvironment, in which the most widespread elements are the stromal cancer-associated fibroblasts (CAFs). However, in veterinary oncology, stromal markers of malignant mammary tumors are insufficiently studied. The aim of the present study is to investigate the expression of tumor marker proteins, i.e. vimentin, α-SMA, and CD34, in the stroma of the malignant mammary tumor microenvironments in dogs. Materials and Methods. The objects of the study that was conducted in the period from 2022 to 2024 were the female dogs of various breeds and ages (n=26). The materials studied were the mammary tumors. A comprehensive range of histological and immunohistochemical studies was conducted in compliance with the standard techniques. Results. It has been established that in different histological types and degrees of canine mammary tumor malignancy, the fibroblastic differentiation lineage cells demonstrate a high expression of vimentin and α-SMA and a low expression of CD34, which indicates their differentiation into CAFs. Discussion and Conclusion. The obtained results can be used as basic applied data in the study of carcinogenesis in veterinary oncology.
A Comprehensive Analysis of Cytotoxicity of Genetically Modified Lactobacillus plantarum 8РАЗ (B-11007) Strain Including Identification and Evaluation of Virulence Factors
Introduction. Active development of biotechnologies and genetic engineering techniques broadens the horizons for engineering the probiotic bacterial strains with tailored functional properties, including the strains based on bacteria of the genus Lactobacillus that are traditionally considered safe microorganisms. Genetic modification enhances their antagonist activity, resistance to adverse environmental factors, and boosts metabolic efficiency. However, bacterial genome editing may entail risk of introducing the undesirable traits, including cytotoxicity and expression of virulence factors. Safety concerns are particularly relevant in the frame of veterinary practice, where probiotics are widely used to correct the gastrointestinal microbiocenosis in agricultural animals and improve their productivity. The aim of the study is to conduct a comprehensive analysis of cytotoxicity of the genetically modified Lactobacillus plantarum 8PAЗ (B-11007) strain including identification and evaluation of the virulence factors responsible for inducing cell death and disruption of cellular functions. Materials and Methods. A genetically modified Lactobacillus plantarum 8PAЗ (B-11007) strain was the object of the study conducted in the period from January to February 2026. A comprehensive in vitro analysis of its cytotoxicity included: assessment of the cytopathic effect in intestinal cell culture, the effect on the viability and metabolic activity of enterocytes, and the state of intestinal epithelial barrier function. Additionally, the analysis of potential virulence factors was performed, along with the study of the mechanisms of cell death, including signs of apoptosis and necrosis. Results. The recombinant Lactobacillus plantarum 8PAЗ (B-11007) strain has demonstrated a high biological safety and pronounced biological activity, which enhanced the intestinal epithelial barrier function by 15.2%, the metabolic activity of cells by 8.7% and simultaneously reduced early apoptosis of enterocytes by 31.1% (p<0.05), showing no signs of cytotoxic action or activation of caspase-dependent cell death. Discussion and Conclusion. The conducted comprehensive analysis allows making the unequivocal conclusion about genetically modified L. plantarum 8PAЗ (B-11007) strain exhibiting no cytotoxic activity in vitro. Moreover, by certain properties (cellular metabolic activity, barrier function), it exceeds the original native strain, which makes it a promising candidate for further preclinical and clinical trials as a potential probiotic agent.
Uncontrollable Mortality in Agricultural Animals in the Russian Federation: A State-Level Problem in the Context of Sanction Restrictions
Introduction. Uncontrollable mortality in agricultural animals causes significant economic damage to the producers, and threatens the national food security. In the context of sanction restrictions, and the need to ensure the independence from import supplies, the problem of livestock mortality control has become particularly acute in the Russian Federation. Although the statistical data are available, the comprehensive analysis of the correlation of livestock mortality and population dynamics, as well as analysis of the factors inducing the growth of mortality are insufficiently presented in the scientific literature. This determines the relevance and purpose of the present study. Materials and Methods. The study was conducted based on the data of the Federal State Statistics Service of the Russian Federation (Rosstat) for the period of 2019–2023. The methods of economic and statistical analysis were used, including the analysis of time series, calculation of livestock population growth rate, structural analysis of the share of mortality in the total figure of livestock population, and comparative analysis of the mortality and population rate changes in the main groups of agricultural animals. Results. The situation has been identified as critical in pig farming, where the livestock mortality-to-population ratio has increased from 32.2% in 2019 to 43.1% in 2023, and in reindeer herding, where this indicator has reached from 14.9 to 19.0%. In most of the animal groups (cattle, pigs, sheep, goats, and horses), the mortality growth rate was found to significantly exceed the population growth rate, and the amplitude of mortality fluctuations was higher, indicating the insufficient level of process control. The key groups of factors influencing mortality have been identified: natural and climatic factors (natural disasters, dangerous diseases), technical and organisational factors (feed shortage, unsatisfactory condition of the premises), and organisational and human (low qualified staff, belated veterinary care). Discussion and Conclusion. The obtained results confirm the existence of a systemic problem of uncontrollable mortality in agricultural animals in the Russian Federation, which requires a transition from the local measures to the State regulation. A set of measures has been proposed, including planning the actions of agricultural enterprises that face the livestock mortality threat, developing an insurance system, strengthening the state support, upgrading employee qualifications, and expanding statistical recording. Implementation of these measures will improve the predictability of livestock population dynamics, reduce the socioeconomic damage caused by the livestock mortality, and strengthen the food security of the country.
Finding Associations of Single Nucleotide Polymorphisms with Exterior Traits (Pelvic Parameters) in Holstein Cows
Introduction. Exterior traits of a cow can have crucial effect on development of pathological conditions, for example, sacrum anatomy features can be related to the risk of dystocia (pathological or difficult parturition). In dairy farming, pelvic parameters are one of the key factors enabling control of easy calving. However, modern breeding focuses on selection of the herd individuals with the highest milk yield and long-term economic productivity, whereas the exterior traits, unfortunately, are taken into account to a lesser extent. The aim of the present research is to identify associations of single-nucleotide polymorphisms with cow pelvic exterior parameters that are important prerequisites of susceptibility to easy or difficult calving. As a result, it will be possible to determine the genetic markers to be included into the selection-breeding programs. Materials and Methods. The study was conducted at Ural Research Veterinary Institute — a structural division of Ural Federal Agrarian Research Center of the Ural Branch of the Russian Academy of Sciences in the period from 2023 to 2025. The exterior trait inheritance patterns were studied in Holstein cows (n=155) across three pelvic dimensions: sacrum height, hip width, and ischial tuberosity width. Association tests were conducted using SNPassoc R package. Results. The mean values and standard deviations for pelvic height at sacrum in cows were found to be 161.7±5.3 cm; for width at hips — 41.1±3.9 cm; for width at ischial tuberosities — 22.4±2.1 cm. For each individual, genotyping with 13 polymorphisms was performed. Rs109452259 polymorphism in C* allele was revealed to have negative effect on hip width in Holstein cows. Rs134055603 and rs43038601 polymorphisms in G/G and C/A genotypes respectively, were established to have putative epistatic interaction with positive effect on the sacrum height. Also, rs134055603 and rs137396952 polymorphisms in C/A and C/C genotypes respectively were found to have possibly synergistic effect. Discussion and Conclusion. The data obtained in the frame of the study are reliable for the observed-level statistical interaction. Potential limitations of the study include possible influence of the unaccounted confounding factors, such as variability of animals within the studied groups by age, live body weight, lactation number, etc. For confirmation of the biological mechanisms, further functional studies are required.
The Small Pond Snail (Lymnaea truncatula) and Its Role in Spreading Trematodiases. The Situation in the Kaluga Region: Literature Review
Introduction. The small pond snail (Lymnaea truncatula) acts not only as a vector for certain species of helminths but also as a universal intermediate host ensuring the circulation of a wide range of trematodes. The increased number of these parasites is a matter of significant epizootological and epidemiological concern as they are posing a threat to the health of humans and farm animals. The aim of the present review is to summarize the available ecology, parasitology, veterinary and epidemiology science data regarding L. truncatula and its role in spreading the trematodiases, particularly in the Kaluga Region. Materials and Methods. The following science citation databases were used: Google Scholar, PubMed, Web of Science, CyberLeninka, Russian Index of Science Citation (RISC/РИНЦ), and others. The publications in Russian and English of the period of 2010–2023 were selected by the keywords: L. truncatula, trematodiases, fascioliasis, dicrocoeliasis, Kaluga Region. Articles that were not peer-reviewed and data without statistical verification were excluded. The results were presented in a PRISMA flow chart. Results. It has been established that the small pond snail plays a key role in the transmission of fascioliasis and is also potentially involved in the spread of other trematodiases. The main factors affecting spreading the infestation include hydrothermal conditions, high soil water capacity, livestock grazing intensity, and the state of melioration system. In the Kaluga Region, the mollusk population density in floodplain biotopes reaches 60–70 specimens/m², and the infestation rate reaches 23%, which creates the stable foci of infestation. The periods of greatest epizootic danger last from June to September. For the efficient control and prevention of trematodiases in the region, a comprehensive approach is required, which combines reclamation works, the use of molluscicides, and modern monitoring systems, as well as systemic collaboration between the specialists of veterinary, agricultural and research institutions. Discussion and Conclusion. When interpreting the results of the present review, it is necessary to remember the limitations typical for this type of research: the risk of biased evaluation of studies due to the predominance of the publications with positive or statistically significant results in the analysed citation databases; the heterogeneity of the included studies, which complicates direct data comparison; the geographical and temporal limitations of data by region, etc. The following areas of research can be of potential importance in the future: studying the influence of the mollusk microbiome on their resistance to infestation; evaluating the efficiency of new biological control methods; and studying the impact of climate changes on parasitic systems. The data obtained will enable the development of a scientifically based trematodiases control system adapted to the Kaluga Region conditions.
Development of an Intelligent System for Diagnosing Rumen Acidosis in Cows. Part 2: Computer Implementation
Introduction. In the first part of the study, the relevance of improving the methods of rumen acidosis diagnostics in cows based on the intelligent systems was substantiated and the use of fuzzy set theory as a tool for such systems was proposed. The structure of the hierarchical-type intelligent system was developed, and formalization of the problem was completed. In the second part of the study, computer implementation of the fuzzy-logic-based intelligent system for diagnosing acidosis was completed using Xcos tool of Scilab software, and a computer application was developed in the Scilab+Scinotes environment as its practical implementation. Materials and Methods. The study was conducted at Ural State Agrarian University and Northern Trans-Ural State Agricultural University from 2022 to 2025. The intelligent system techniques, fuzzy set theory and fuzzy logic methods, and Mamdani fuzzy inference system were used to conduct the study. A computer model for rumen pathology assessment was created based on the generalized smart system by means of Xcos tool of Scilab software. Computer implementation of the intelligent system was completed in the Scilab+Scinotes environment. Results. For solving a problem of hierarchical-type intelligent system, the production rule bases, which included various combinations of diagnostic parameters and respective degrees of rumen acidosis pathology, were developed. Synthesis of fuzzy systems was performed using SciFLT tool of Scilab software. A generalized model of an intelligent system for diagnosing rumen acidosis in cows was developed using Xcos tool of Scilab software. Computer implementation of the intelligent diagnostic system was completed in Scilab software with embedded Scinotes text editor. Discussion and Conclusion. The model of an intelligent system proposed by the authors is innovative and can be recommended for practical implementation into the expert advisory systems, for automation of veterinary workstations, and for using in modern veterinary telemedicine technologies.
A Clinical Case of Proliferative and Necrotizing Otitis Externa (PNOE) in an Elderly Cat
Introduction. A clinical case of proliferative and necrotizing otitis externa (PNOE) in an elderly cat has been described, i.e. diagnostics and treatment with tacrolimus. This syndrome of unknown etiology occurs in cats aged from 2 months to 12 years. It bilaterally affects the concave pinnae and the external acoustic pore. Disease development in the ear canal is accompanied with the secondary bacterial or Malassezia otitides. Fifteen foreign works investigating PNOE in cats and dogs published in the period of 2000–2025 have been reviewed. Materials and Methods. In November 2024, the owners of a five-year-old cat attended to the veterinary clinic “Center” (Rostov-on-Don) with the complaint on frequent otitides in their pet. PNOE diagnosis was based on the animal’s medical history, clinical examination, microscopic and cytological examination of discharge from ears (performed in the “Vet Union” veterinary laboratory, Moscow). Treatment included topical application of 0.1% tacrolimus ointment. Results. Examination of the inner surface of the auricles revealed stenosis of the external ear canals and a significant number of black, dry crusts. An ear culture test revealed secondary microbial contamination with Pseudomonas aeruginosa, Klebsiella oxytoca, and Enterobacter cloacae; whereas, Candida or Malassezia spp fungi were not isolated. Also, during microscopy of earwax, no mites of the genus Otodectescynotis were isolated. After 4 weeks of treatment with 10 g of 0.1% tacrolimus ointment applied topically, normalization of condition was noticed during the otoscopic examination of the auricles. Discussion and Conclusion. The efficiency of treating PNOE in cats with tacrolimus ointment applied topically to the auricle crusts has been proved. The data and photographs presented in the article may be useful for practicing veterinarians for diagnostics and treatment of this relatively rare disease.
Prevalence of Trematodes of the Family Notocotylidae in the Perm Territory
Introduction. Notocotylidoses are fairly widespread in Russia dixenous trematode diseases of birds and some mammals caused by the members of the family Notocotylidae, which parasitize in the intestines. Although the Perm Territory conditions (hydrological situation, prevalence of susceptible hosts) are apt to the increase of the population of this trematode species, the epizootic situation for this trematode in the region remains unstudied. The aim of the article is to investigate the prevalence of trematodes of the family Notocotylidae in the Perm Territory. Materials and Methods. The objects of the study were freshwater gastropods (n=340), cadavers of wild waterfowl (n=16) and samples of mallards’ droppings from the places of their aggregations (n=139) collected in the Perm Territory during the warm seasons of 2024 and 2025. The research was carried out at Perm State Agro-Technological University named after Academician D.N. Pryanishnikov in compliance with the standard techniques: using microscopy compressor; partial helminthological dissections; sequential washings of droppings; standard histological examination of tissues of infested mollusks and ducks. Results. A single Anisus vortex specimen from the Motovilikha Pond (Perm) was found to be infested with cercaria of Notocotylus sp. Also, marita of N. attenuatus was found in the intestines of a Clangula hyemalis. In the histological samples of the infested mollusk, edema, friable tissues, mucin hypersecretion were revealed, and single cercariae were isolated. Also, the exposure of bird’s intestines to N. attenuatus resulted in chronic condition manifested in edema and degenerative changes in the tissues, as well as the development of the macrophage response in the lymph nodes. Discussion and Conclusion. The presence of larval notocotylids in the Perm Territory did not confirm having a natural focus of avian notocotylidosis there. In this case, mammals are likely to be the definitive hosts. Marita of N. attenuatus was detected in a migratory species, in the long-tailed duck, which might have been infested in its wintering or nesting areas.
A Study on Morphofunctional State of Djungarian Hamster (Phodopus Sungorus) Lungs and Main Organs of Detoxification under Long-Term Exposure to E-Cigarette Aerosol
Introduction. The liquids of electronic nicotine delivery systems (ENDS), which have the multi-component composition, represent a major environmental hazard, as they contain extremely toxic substances. Although the popularity of this form of smoking grows, the data on the biological effects of long-term exposure of animals and humans to e-cigarette and vape components are insufficient. The aim of the present study is to investigate the morphofunctional state of the lungs and main organs of detoxification in Djungarian hamsters under long-term exposure to ENDS aerosol. Materials and Methods. The research was conducted in 2021 in the colony of laboratory Djungarian hamsters kept at the Institute of Systematics and Ecology of Animals SA RAS. Thirty-six hamsters were divided into two groups. During 80 days, animals in the experimental group (10 females and 10 males) were exposed to vapour from heating the X-3 Yoghurt Pear liquid. The procedure was performed twice a day for 10 minutes, with a 2-hour interval. Hamsters in the control group (8 males and 8 females) were placed in exposure chambers but were not exposed to vapour. At the end of the 80-day experiment, the animals were decapitated, and organs were collected for preparing thin histological sections. The specimens were stained with Boehmer’s hematoxylin and eosin. Collagen distribution was determined using the Mallory method. Histological specimens of organs were examined under transmission light microscope Results. In experimental animals exposed to toxic vapour, a homogeneous black substance was detected in bronchial epithelial cells and in the alveolar interstitium. In the lung parenchyma, signs of developing interstitial pneumonia, atelectasis, emphysema, and obstructive bronchitis were detected, indicating impaired ventilation-perfusion relationships in the lung tissue and gas exchange disorder. In the kidneys, the homogeneous substance was localized in the lumen of renal tubules. Light optical microscopy revealed the main signs of lethal damage in renal epithelial cells. Strongly expressed dilation of the renal glomerular capillaries, coupled with a nearly 2-fold reduction in the surface area of renal corpuscles compared to control samples, indicates impaired hemodynamics and disrupted renal reabsorption-filtration function. Regarding the liver, a high level of localization of evolutionarily adapted to detoxification dark hepatocytes dying by apoptosis in the centrilobular region of the lobule, indicates the involvement of toxic substances in this process, which enter the liver with the blood. Discussion and Conclusion. The experiment demonstrated the general pathogenic effects of ENDS aerosol on the lungs and organs of detoxification in animals after long-term exposure to it. Such studies are necessary in the context of the observed growth of consumption of the nicotine delivery systems at the global market.
Basic Principles and Practical Instructions for Proper Feeding of Donkeys
This paper presents the nutritional requirements of donkeys, with a special focus on the needs for water, energy, proteins, minerals and vitamins. Donkeys, as working animals originating from arid regions, have specific physiological adaptations that affect their nutritional needs. The aim of this paper is to review and present scientifically based information on nutritional requirements, nutrients and recommendations for feeding donkeys based on current research in the world. The paper shows the needs for water, energy, proteins, minerals and vitamins, as well as methods of assessing food digestibility and availability. Special attention is paid to the variations in needs depending on the physiological state (growth, pregnancy, lactation), the intensity of work and the quality of available food. The importance of food digestibility and correctness of meal that meets all nutritional needs are also presented. The need for an adequate balance between rough and concentrated feed, as well as the potential danger of inadequate supplementation, are emphasized. Based on the available literature and field observations, practical instructions are given for proper feeding of donkeys in different breeding conditions, with the aim of preserving their working capacity, health and longevity.
Assessing Kidney Tissue Density Changes in Rats with Hyperlipidemia Using Micro-CT
Introduction. Computed X-ray microtomography (micro-CT) enables getting the three-dimensional images of microscopic structures without damaging them, which makes this method widely implemented in biomedicine. Regarding the application of micro-CT in veterinary medicine, its potential in assessing morphological changes in internal organs of animals with pathologies has not yet been used at full scale. For example, there are no enough data on the capacity of microtomography in studying pathological processes in kidneys of animals. The aim of the present study is to assess the pathological changes in the density and morphology of kidney tissue in laboratory rats with hyperlipidemia using micro-CT. Materials and Methods. The experiment was conducted at DSTU from 2021 to 2024 and involved 40 male Wistar rats divided into 5 groups: 4 experimental and 1 control. During the experiment, the experimental groups were fed a hyperlipidemic diet; the control group received only standard feed-stuff. Kidneys were taken from decapitated animals on 30th, 120th, 150th, and 180th day, and samples were prepared for scanning with a Zeiss Xradia Versa 520 micro-CT scanner at 80 kV and voxel size of 20 μm. The efficiency of micro-CT was assessed by the quality of 3D reconstruction and detected changes in kidney tissue density and morphology at different stages of hyperlipidemia. Results. Microtomograms of kidneys of rats in the experiment allowed for detailed visualization of the organ’s morphology, including renal cortex and medulla, as well as vasculature. Quantitative data on changes in tissue density were obtained, and differences in kidney structure were distinguished between the normal (in control group) and pathological conditions (in experimental groups with various degrees of hyperlipidemia). Discussion and Conclusion. Micro-CT method has demonstrated high accuracy and informative value in analysing kidney tissue condition in rats and proved its efficiency in early diagnostics of pathological changes in these internal organs, as well as in dynamic monitoring of disease. Among the constraints of this method, the following aspects can be noted: the high cost of equipment, low sensitivity to soft tissues in the absence of contrast-enhancement, and the need for specialized skills to interpret the images.
The Efficiency of Modeling Oxidative Stress in Rats by Exposure to Noise Compared to Exposure to Hyperthermia or Magnetic Field
Introduction. In vivo model for experimental creation of the necessary pathological processes is an important element of scientific research planning. Numerous series of experiments have demonstrated the relevance of modeling oxidative stress in laboratory rats by exposure to hyperthermia, magnetic field and noise. The problem of finding the advantages of each particular prooxidant factor in modeling stress response underlies the current experiment, and its expediency is induced by the need to generate a robust response of the prooxidant/antioxidant system, with statistically significant changes of its parameters, at various periods of time. The study aims at conducting a comparative assessment of the effect of noise, hyperthermia, and magnetic field on the intensity of lipid peroxidation processes in rats. Materials and Methods. The study was conducted at the Research Laboratory of Amur Medical Academy in 2023–2024. The experiment involved 120 white rats divided into four equal in number groups. The animals in the first group (intact) were not subjected to any impacts; the animals in the second group (experimental group 1) were subjected to hyperthermia; the animals in the third group (experimental group 2) were exposed to magnetic field; and the animals in the fourth group (experimental group 3) were exposed to noise. On 7th, 14th, and 21st days of the experiment the rats were decapitated (10 animals from each group) and their blood was sampled for analysis. Oxidative stress markers were determined using the standard techniques; the results were analysed using the Mann-Whitney and Kruskal-Wallis tests. The critical significance level was set to 0.05 for all assessment procedures. Results. With regard to the influence on the accumulation degree of conjugated dienes, statistically significant advantages of noise model over the magnetic field model were recorded (p=0.000005 on 14th and 21st days) and over hyperthermia model (p=0.002039 on 14th day; p=0.001837 on 21st day). With regard to malondialdehyde, noise exposure surpassed hyperthermia by the end of the experiment (p=0.000561). With regard to ceruloplasmin, the advantages of the noise model over hyperthermia model were established (p=0.0167980 on 7th day; p=0.004813 on 21st day), as well as over the magnetic field model (p=0.000005 at all control points). In relation to vitamin E, the noise model advantages over the magnetic field (p=0.000006 on 21st day) were revealed. Discussion and Conclusions. Significant advantages of the noise-exposure model over the hyperthermia- and magnetic-field-exposure ones in modeling the oxidative stress were established, along with the respective changes in prooxidant/antioxidant system components. By the end of the first, second, and third weeks of the experiment, the statistically significant deviation of oxidative stress markers in laboratory animals occurred under exposure to noise, unlike exposure to temperature and magnetic field. In future, studies on the acoustic load influence on the adaptive potential of warm-blooded organisms are planned to probe possible pharmacological medications to negative influence of noise.
Infestation of Black Sea-Caspian Sprat (Clupeonella Cultriventris) with Cestodes of the Genus Proteocephalus in the Kama Reservoir and Histological Examination of Fish Intestines Infested with These Parasites
Introduction. The Black Sea-Caspian sprat (Clupeonella cultriventris) is an alien species adapted to the Kama Reservoir conditions, capable of affecting the trophic relationships in this ecosystem. However, the composition of helminth fauna in this ecosystem and the pathological changes induced by the certain pathogens, such as cestodes of the genus Proteocephalus, are currently poorly investigated. The aim of the study is to investigate the infestation of C. cultriventris with cestodes of the genus Proteocephalus in the Kama Reservoir and to describe the histological changes in the fish intestines caused by this infestation. Materials and Methods. In the autumn-winter period of 2024, the C. cultriventris (n=83) were taken from the several parts of the Kama Reservoir. A partial biological analysis, partial helminthological dissection and histological examination of the intestines infested with cestodes were carried out. Parasitological examination was performed at the Department of Infectious Diseases of Perm State Agro-Technological University. Preparation of histological specimens was performed in the histopathology laboratory of Perm Regional Children’s Clinical Hospital. The prepared histological sections were scanned using the Vision Assist automated system and Vision microscopy automation software. Mathematical processing of the obtained data was performed in Microsoft Excel. Results. The highest infestation extensity (IE 50%) of Proteocephalus sp. (juv) corresponding to infestation intensity (II) range 1–2 was observed in sprat form the middle part of the Kama Reservoir; in sprat from the upper part, it was several times less (IE 13% corresponding to II range 1–3); sprat from the lower part was not infested at all. The size and weight parameters in sprat from the upper and lower parts of the Reservoir were significantly higher than that in the fish from the middle part — approximately 2 times exceedance in weight and 1.2 times — in length. Histological examination of sprat intestines revealed changes in mucosa and submucosa layers; the epithelium was in a state of desquamation, the stromal state of the villi was loose and edematous. Discussion and Conclusions. Data on infestation of C. cultriventris with the cestodes of the genus Proteocephalus sp. in the Kama Reservoir are presented for the first time. It has been revealed that cestode infestation affects the biological parameters of fish and causes minor inflammatory pathological changes in the intestines. Detection of the pre-mature cestodes in the non-specific hosts is not enough factor for their identification, therefore, further research is needed to clarify the host-parasite relationships of C. cultriventris and Proteocephalus sp.
Development of an Intelligent System for Diagnosing Rumen Acidosis in Cows. Part 1: Formalization of Tasks
Introduction. Improvement of the diagnostic methods for detecting bovine ruminal acidosis is a relevant problem due to the prevalence of this disease resulting in cattle murrain. The most future-oriented methods of early diagnostics of this pathology are prophylaxis campaigns or individual examinations of animals using the online services in the frame of veterinary telemedicine technologies. However, in Russia, the efficient use of these technologies is hindered by the absence of well-developed methods of assessing the pathology based on the mathematical tools integrated into the advanced intelligent systems. In our study, we attempted to create an intelligent system for diagnosing rumen acidosis in cows. The first stage of the research consisted of formalization of tasks based on the concept of fuzzy logic. Materials and Methods. The study was conducted at the Ural State Agrarian University and the Northern Trans-Ural State Agricultural University from 2022 to 2025. For diagnosing rumen acidosis, a minimum list of diagnostic parameters was determined as input variables for the fuzzy system (based on the analysis of data obtained from the specialized reference books and scientific publications). Due to the possible difficulty of combining several parameters exceeding reference values, a method for representing uncertainties — fuzzy set theory — was used to correctly solve the problem in the given settings. A hierarchical structure was chosen to build the intelligent system, which makes it strictly logical and transparent for analysis. Scilab open source software with embedded text editor Scinotes were used to develop the application. Results. A set of necessary diagnostic parameters including pH of rumen contents, fat content in milk, pulse rate, and respiratory rate was justified. A substantive formulation and formalization of the problem of fuzzy inference for assessing rumen acidosis pathology in cows was completed. The structure of the hierarchical-type intelligent system was developed. All variables, including intermediate ones, were formalized within the fuzzy model of the intelligent diagnostic system. Discussion and Conclusion. In the first part of the study, we have established the formal models of all variables (input, output, and intermediate) for solving the task of diagnosing rumen acidosis in cows. In case of emergence of new parameters directly related to acidosis, they can also be integrated into the intelligent system. Based on the formalized data obtained at this stage of the research, in the second part of the study, it is planned to apply computer technologies to create the intelligent system for assessing rumen acidosis pathology in cows.