Introduction. Listeria monocytogenes is a pathogenic microorganism that causes a large number of deaths due to the consumption of contaminated animal products. This underpins the relevance of monitoring the spread of the listeriosis agent in raw materials, animal products, and environmental objects, as well as the antibiotic resistance of isolates. Objective. Serotype identification and antibiotic resistance analysis of Listeria monocytogenes isolates recovered from animal products in 2021–2024. Materials and methods. The work was performed at the Microbiology Unit of the Vladimir Testing Laboratory, the Federal Centre for Animal Health. Listeria genus bacteria isolates were identified using time-of-flight mass spectrometry. Antibiotic resistance of isolates belonging to the species Listeria monocytogenes was determined by the disk diffusion method. The values of the growth retardation zones were interpreted according to the Russian recommendations “Determination of the sensitivity of microorganisms to antimicrobial drugs” (IACMAC, version 2025-01). Listeria serological groups were identified using real-time polymerase chain reaction (qPCR) with primers manufactured by Syntol (Russia). Results. The article presents the results of antibiotic resistance testing of 77 Listeria monocytogenes isolates detected in animal products in 2021–2024, as well as their differentiation by serogroups. Listeria monocytogenes was most frequently detected in poultry products. The detected isolates showed maximum resistance to cefuroxime, sulfamethoxazole/trimethoprim, norfloxacin, rifampicin, levofloxacin, and kanamycin. Moreover, most isolates exhibited resistance to more than one antimicrobial medicinal product. The study established the belonging of the Listeria monocytogenes isolates to the following serogroups: IIa (serotypes 1/2a, 3a) – 92.2%; IIc (serotypes 1/2c, 3c) – 5.2%; IVb (serotypes 4b, 4d, 4e) – 2.6%. Conclusion. The spread of resistance, including multidrug resistance, among Listeria monocytogenes isolates detected in animal products in 2021–2024 was demonstrated. The study identified the presence of listeria belonging to group IVb (serotypes 4b, 4d, 4e). However, the dominant part of Listeria monocytogenes isolates was classified as group IIa (serotypes 1/2a, 3a).

Introduction. Avian influenza virus (AIV) and Newcastle disease virus (NDV) pose serious threats to poultry health. Both pathogens are highly contagious and, due to their rapid spread, can lead to significant economic losses. Overlapping clinical signs complicate field differentiation of these diseases and delay response measures to isolate affected poultry. Rapid disease detection is critical for ensuring a timely response. Objective. To develop a user-friendly test kit for detection of AIV and paramyxoviruses in organ samples from sick and dead chickens during disease outbreaks in commercial poultry operations. Materials and methods. To differentiate AIV and paramyxoviruses in pathological samples collected from sick and dead birds, 96-well plates coated with fetuin and anti-NDV IgY in designated wells were used. The results obtained were compared with those from polymerase chain reaction (PCR) and virus titration in chicken embryos. Results. The developed method for pathogen detection is based on distinct virus-binding principles: influenza virus binds to a receptor analog, while paramyxoviruses bind to NDV specific antibodies. Previous studies using hundreds of strains have demonstrated that influenza A virus of various subtypes binds to the sialoglycosyl residues of bovine fetal serum protein – fetuin. In contrast, none of the paramyxovirus isolates tested bound to this sialoglycoprotein. For paramyxovirus capture, immunoglobulins isolated from the egg yolks of chickens immunized against NDV were utilized. Binding was performed in 96-well plates using a test-kit analogous to enzyme-linked immunosorbent assay (ELISA). Conclusion. The developed method enables the identification and differentiation of AIV and NDV in organ tissue homogenates from infected chickens within a few hours, representing a significant step toward preventing the spread and facilitating the eradication of dangerous disease outbreaks.

Introduction. West Nile fever is a zoonotic transmissible disease caused by flavivirus that primarily circulates in nature within an enzootic cycle between mosquitoes and birds, and causes disease cases in humans, horses, and other mammals. The rapid expansion of the West Nile fever pathogen range, development of outbreaks with severe clinical manifestations, and the lack of specific preventive tools have been the main arguments for classifying it as a poten­tially dangerous threat to global health. The close interconnection between human health, animal health, and ecosystems necessitates communication and coordination across the relevant sectors. One Health is an integrated, unifying approach aimed at optimizing the health of humans, animals, and ecosystems involving public health, veterinary and environment protection authorities. Objective. Analysis of basic epizootological data on the spread of West Nile fever in the Russian Federation. Materials and methods. The following international and Russian databases were used for literature searching: PubMed, Springer, Google Scholar, CrossRef and Russian Science Citation Index (RSCI), еLibrary, CyberLeninka, respectively. The searching was performed based on the following key words: West Nile fever, One Health, migration of birds, invertebrate hosts, control measures. Results. In Russia, West Nile virus was first isolated in Astrakhan Oblast in 1963. Currently, presence of the pathogen has been proven in the southern and central regions of the European part of the country, in the south of Western Siberia and the Far East. The lack of disease monitoring in some Russian regions and small numbers of samples tested in most subjects of the Russian Federation hinder an objective assessment of the disease situation, so there is a need to increase the number of tests. It has been shown that the main carriers of the pathogen in our country are mosquitoes of the genera Culex, Anopheles and Aedes, ixodid, argasid and gamasid ticks are also involved in maintaining the virus circulation. The review describes the role of birds in the pathogen transmission, provides data on susceptibility of animals to the infection, discusses modern aspects of West Nile fever diagnosis, prevention and control. Conclusion. Surveillance of West Nile fever presents a considerable challenge, as the virus circulates among humans, arthropods, and birds. While vaccination is an effective preventive tool, no vaccines against the disease have yet been developed in Russia. In this context, strengthening inter-authority coordination and implementing environmental control measures to limit the virus spread are essential priorities.

Introduction. In 2024–2025, a number of high pathogenicity avian influenza A(H5N1) outbreaks were reported in dairy cattle. Such an expansion of the range of the virus hosts increases global risks for livestock farming and public health, which requires strengthening animal disease monitoring and control systems. Objective. Analysis of the epizootological characteristics of avian influenza A(H5N1) virus infection in dairy cattle and other mammals in 2024–2025, as well as summary of the response measures taken and recommendations of international organizations. Materials and methods. Analytical research methods were used utilizing PubMed, Scopus, Web of Science, Springer, Wiley Online Library databases and materials from international organizations (FAO, EFSA, WOAH, OFFLU, CDC). Results. Outbreaks of avian influenza A(H5N1) caused by clade 2.3.4.4b virus of genotypes B3.13 and D1.1 in dairy cattle in 2024–2025 occurred as a result of three confirmed independent cases of the pathogen transmission from wild birds. The infection was detected on 1,078 cattle farms in 17 US states. Subsequent virus transmission to poultry, wild and domestic animals, including cats, as well as to humans (70 people), mainly those working on animal and poultry farms, was reported. Reverse transmission of the pathogen from cows back to birds was documented as well. Rapid and wide spread of the virus is associated with extensive animal movements and insufficient biosafety measures. Influenza A(H5) is recommended for the inclusion in the differential diagnosis for cattle, pigs, domestic and wild animals. Conclusion. Avian influenza A(H5N1) epizootic in cattle and the infection transmission to other mammals pose a serious threat to livestock production and public health. In response to the existing risks, it is necessary to strengthen biosafety measures and surveillance in epidemiologically significant animal populations, incorporate the experience of other countries and establish international cooperation to study the trends of the virus evolution.

Introduction. Foot-and-mouth disease is one of the key threats to global animal welfare and international economic relations. Like any other transboundary animal disease, it shall be notified to the World Organisation for Animal Health (WOAH) in accordance with the relevant international standards. By 2016, the largest part of the territory of the Russian Federation (i. e. 50 subjects and 2 federal cities) had been recognized by the WOAH as an FMD-free zone without vaccination. From 2021 to 2023, 4 more zones of the country were granted the status of freedom from foot-and-mouth disease with vaccination. At the end of 2024, only 10 subjects of the Russian Federation, all located within zone Western Siberia – Urals, lacked official recognition. Objective. Descriptive analysis of the animal health situation in the Russian Federation from 2021 to 2024: substantiating success of the Rosselkhoznadzor’s systematic approach to regionalization in accordance with the WOAH Terrestrial Animal Health Code. Materials and methods. Various information sources were used to collect and analyze materials on the animal health situation in Russia, including the USSR archives, veterinary reports, and the WOAH statistics. Results. FMD situation was analyzed in 10 subjects of the Russian Federation bordering on the Republic of Kazakhstan, with an emphasis on FMD control measures, regionalization and zoning. This section focuses on distribution of statuses across Russia’s administrative subjects and the historical records on the disease outbreaks. It also outlines regulatory and surveillance measures implemented by the Federal Service for Veterinary and Phytosanitary Surveillance (the Rosselkhoznadzor) to manage the FMD status in various regions, taking into account the prophylactic measures implemented in place. The paper describes these measures and their results step-by-step, showing a dynamic improvement of the FMD surveillance system. Conclusion. On 29 May 2025, at the 92 nd WOAH General Session of the World Assembly of Delegates, Zone Western Siberia – Urals was officially recognized as a foot and-mouth disease-free zone with vaccination. This decision completes the process of structuring the territory of the Russian Federation into 6 zones. The WOAH-granted disease-freedom statuses confirm efficacy of the preventive and surveillance measures, which is crucial to ensure global epizootic stability. These accomplishments result from the efforts jointly taken by the Rosselkhoznadzor and its subordinate institution the Federal Centre for Animal Health.

Introduction. Newcastle disease is a notifiable disease and is a major threat for commercial poultry. There are many known genotypes of the Newcastle disease virus (NDV), which differ in virulence. In recent years, there is an increasing interest in NDV genotype VII that stems from its prevalence and high pathogenicity in chickens and other species of commercial poultry, causing severe disease with up to 100% mortality. Objective. Investigation of the infectious process and other clinical and post-mortem signs in chickens infected with Newcastle disease virus via different routes. Materials and methods. Thirty-day-old chicks were experimentally infected with NDV genotype VII via three different routes: intranasal, oral and intramuscular. Forty eight hours post infection, six intact chickens were introduced in each group. Over the next 10 days, the clinical condition of the infected and contact poultry was assessed. Oropharyngeal and cloacal swabs were collected and tested by polymerase chain reaction. Dead chicks were subjected to post-mortem examination. Results. The experiment demonstrated that NDV/chicken/rus/Saratov/2403-3/22 isolate causes poultry mortality within 5–7 days. Intramuscular infection led to faster disease progression and death in poultry compared to oral or intranasal routes. The NDV genome was identified in samples of oropharyngeal and cloacal swabs tested by polymerase chain reaction. While nonspecific signs of the disease were recorded in all individuals, the predominant clinical presentation varied with the infection route. Pronounced neurological symptoms were observed in birds infected via the intramuscular and oral routes. In contrast, respiratory signs were characteristic of infections via the oral and intranasal routes. The autopsy results indicate that specific pathological signs characteristic of Newcastle disease developed within 24 hours of the disease onset. A number of post-mortem lesions were found in the internal organs of individuals that died early. However, these lesions were not informative for a diagnosis of Newcastle disease. Conclusion. The Newcastle disease virus NDV/chicken/rus/Saratov/2403-3/22 strain (genotype VII) was pathogenic to chickens during experimental infection. The disease was easily reproduced by intramuscular, intranasal, and oral routes of infection and was characterized by a peracute course with respiratory and neurological symptoms.

Introduction. In Burundi, where 80% of the population are engaged in livestock farming, industries with short reproduction cycles (pig farming, poultry farming) prevail. Despite government support measures and annually increasing pig population, the country has been unable to fully meet the demand for livestock products. This is due to numerous problems in the sector, with infectious animal diseases being the primary issue. Infectious disease outbreaks can have catastrophic consequences for the human population, including threats to food security, loss of access to animal protein, increased production costs due to the need for expensive disease control measures, and risks to human health in case of zoonotic diseases.Objective. The aim is to study the nosological profile of porcine infectious diseases, identify factors contributing to animal infections and assess the swine erysipelas epizootic situation in the Republic of Burundi from 2018 to 2023.Materials and methods. Data of annual reports of the General Directorate of Animal Health and test results of the National Veterinary Laboratory of Burundi (2018–2023) were used to analyze the epizootic situation on infectious porcine diseases. Retrospective and epizootiological analyses were conducted and variational statistical methods were applied.Results. The analysis revealed a high prevalence of porcine parasitic diseases, which is attributed to the equatorial climate. Within the overall structure of infectious diseases, parasitic infestations ranked first, growing from 81.2% in 2018 to 92.8% in 2023. Bacterial infections were the second most widespread, rising from 3.6% in 2018 to 6.3% in 2023. A steady increase in swine erysipelas cases was observed: in 2023 the number of cases was 1.7 times higher than in 2022 and seven times higher than in 2020. Moreover, the number of provinces where the disease is detected is annually growing. Swine erysipelas is currently reported in 12 out of 18 Burundian provinces.Conclusion. The Republic of Burundi suffers significant annual losses due to animal deaths caused by infectious disease outbreaks. In the absence of specific disease prevention measures (particularly for erysipelas) and weak veterinary control of animal movements between households, infections spread rapidly. Therefore, studying the epizootic situation and developing measures to stabilize it under local conditions is a crucial scientific and practical task for ensuring biological and food security.

Adenovirus infection in dogs caused by canine adenovirus serotype 2 predominantly results in respiratory disease typically manifested by respiratory tract lesions. Infectious laryngotracheitis is the most often recorded in dogs in the central part of the Russian Federation and its incidence tends to increase. Therefore, preventive immunization against this disease remains important. Primarily, the virus strains currently important and circulating in the particular territory shall be used for vaccine production to induce long-term and strong immunity in animals. The study was aimed at isolation of canine adenovirus type 2 remaining stable during five or more passages from the biological samples collected from animals with adenovirus infection signs as well as at determination of its cultivation parameters. As a result, five virus isolates were recovered, one of the recovered virus isolates had optimal properties for its use for vaccine production. Comparative analysis of continuous Vero, MDCK (NBL-2 and NBL-9 line) cell cultures as well as primarily trypsinized cell cultures (baby dog kidney, baby dog spleen, baby cat kidney, baby cat spleen) for their susceptibility to the recovered virus showed that MDCK (NBL-2 line) was the most susceptible. The virus cultivation parameters in this cell culture was determined at the next step. The following optimal conditions under which the virus accumulated to the maximum titres were determined: cell culture monolayer age for inoculation – 48 hours, multiplicity of infection – 0.01 TCID50/cell, preliminary holding time – 60 min, temperature – (37.0 ± 0.5) °С, cultivation period – 120 hours.

Listeriosis is one of the most severe gastrointestinal diseases in the world. Listeria affect different groups of animals and birds. The pathogen has been detected in meat, milk, fish and fish products. The disease shows spring and autumn seasonality. It has been reliably established that Listeria monocytogenes is ubiquitous in the environment. Listeria monocytogenes is a facultative intracellular pathogen. Infection with Listeria monocytogenes causes an invasive disease in animals and humans, which is transmitted via the fecal-oral route from an animal to a human, from a mother to a fetus. The pathogenesis of Listeria infection has been well studied. The gastrointestinal tract is the site of the pathogenic Listeria species transit and spread. The infection incubation period is 20–30 days in animals and humans. The clinical course in different animal species, including birds, has a number of specific features. Listeria can cross the intestinal, placental and blood-brain barriers. The manifestations of listeriosis include encephalitis, meningitis, gastritis, meningoencephalitis, mastitis, abortions, endometritis, etc. Pathogenic Listeria species show hemolytic activity which non-pathogenic species (except Listeria seeligeri) lack. The review presents the up-to-date information on the classification of Listeria, the pathogenicity factors of Listeria monocytogenes as the major pathogen, the mechanisms of Listeria infection development in different animal species.

Currently, veterinarians pay much attention to the diagnostic examination of animals, including animals kept on fur farms. Blood is the main material used for such examinations. Changes in its composition allows veterinary practitioners to identify disorders in various systems and organs of animals, as well as to assess metabolism in animals. Results of biochemical tests of serum samples from platinum fox males and females of different age groups and comparative assessment thereof are presented. The levels of aspartate aminotransferase (U/L), alanine aminotransferase (U/L), alkaline phosphatase (U/L), total protein (g/L), albumin (g/L), urea (mmol/L), creatinine (μmol/L), α-amylase (U/L), cholesterol (μmol/L) were determined. Aspartate aminotransferase levels in females at the age of 6 months were lower by 69% than that ones in males. Increase in aspartate aminotransferase by the age of 6 months helps animals to accumulate body weight before winter. Sexual differences in the alkaline phosphatase levels were detected in 1.5-month-old kits: alkaline phosphatase levels were higher by 21.05% in males than in females. By the age of 6 months, the alkaline phosphatase levels decreased in both males and females. The decline in alkaline phosphatase level with the age is associated with participation of this enzyme in the development of animal skeleton during ontogenesis. From the age of 4 months, the growth and development of the skeleton slows down, and by the age of 6 months the animals gain the size and body weight of adult animals. Urea and creatinine levels in foxes of both sexes increased during their growth, but remained within the reference limits. Changes in urea levels in blood can be caused by feeding excessively high-protein or excessively low-protein diets. The total protein content in sera from 4 month-old males and females decreased by 32.51 and 43.24%, respectively, compared with that one in sera from animals at the age of 1.5 months, and increased at the age of 6 months up to the level observed at the age of 4 months. According to the literature, rather rapid stabilization of protein metabolism is a biological feature of many mammals born in spring, their growth rate is accelerated and, in general, the maturity phase is shortened.