The article presents the results of electron microscopic studies of blood samples of cattle infected with monoinfections: bovine leukemia virus, foot-and-mouth disease virus and bovine ephemeral fever virus. Previously, the author identified nanometer-sized microorganisms in the blood of animals and humans with pronounced signs of gram-negative prokaryotic cells and characterized as nanobacteria. Nanobacteria at a concentration of 108-1010 cells/ml were detected by electron microscopy in the blood of animals infected with the virus of leukemia, foot-and-mouth disease and ephemeral fever. In addition, the technique, which includes the stages of freezing-thawing of blood samples and subsequent double centrifugation (500 and 2000 g), allows to identify cells of lymphocytes affected by nanobacteria, which gives grounds for concluding about associated effects on lymphocytes of nanobacteria and viral pathogens. It is quite obvious that the death of immunocompetent cells from nanobacteria, as well as their presence in high concentrations in the blood and organs of animals, loads the bodys immune system and thereby contributes to the development of secondary immunodeficiency with all its consequences

African swine fever (ASF) is a deadly and dangerous viral disease of pigs and wild boars, which leads to significant economic losses. Despite the progress in the study of immunopathology in ASF, the creation of a universal effective and safe vaccine against ASF virus has not been successful so far. This is due to the complex structure of the virus, the high variability of the genome and the presence of a large number of immunomodulating proteins. As is the case with other large DNA viruses, the ASF virus genome encodes several proteins that help the virus evade the host's immune response. One of them is the powerful immunosuppressant protein 5EL (A238L gene) - an IkB homolog and calcium neurin phosphatase inhibitor that causes programmed cell death. The aim of the study was to obtain a recombinant ASF virus with deletion of the A238L gene by homologous recombination and to study its reproduction in vitro. As a result, a recombinant Volgograd / 14c ΔA238L ASF virus was obtained from the strain of ASF virus «Volgograd / 14c» in the transplanted cell culture COS-1. According to the results of our studies, the removal of the A238L gene from the virulent Volgograd / 14c strain did not lead to a change in the cultural properties of the recombinant Volgograd / 14c ΔA238L virus in the transplanted cell culture COS-1. Reproduction of the recombinant strain Volgograd / 14c ΔA238L in primary culture of pigs macrophage cells and COS-1 cell culture is 4.0-5.0 lg GAE 50 / cm³. There were no differences in the the dynamics of reproduction of the initial and recombinant strains. It was shown that reporter fluorescence of the EGFP gene is observed at different multiplicity of infection (0.1 and 1), which indicates the effective replication of the virus

The article presents the results of a retrospective assessment of the epizootic situation for leukemia article presents the results of a retrospective assessment of the epizootic situation for leukemia in 16 pedigree dairy farms over 11 years of observation. One of the reasons restraining the development of livestock breeding in the Dagestan Republic is the high infection rate of bovine leukemia, such as the disease is prolonged and widespread. Serological and hematological studies were carried out in accordance with the methodological recommendations approved by the Veterinary Medicine Department of the Russian Federation (2000). The analysis of statistical data revealed that the level of infection of animals in 2009-2017, on average, amounted to 28.03 %, the number of patients - 30.62 %, to the number of examined. With the implementation of the Republican Program, the epizootic state in pedigree farms improved. Thanks to preventive and health measures, the coverage of livestock with hematological and serological tests for leukemia in 2019, compared with 2018, increased by 2 or more times, the infection rate of animals decreased from 14.57 to 5.3 %, the incidence rate - from 21.09 to 7.14 %, the number of contaminated farms - from 8 to 4, respectively. At the beginning of 2019, among pedigree farms 4 contaminated farms were registered. There were 23 sick animals, which were killed.

Ixod mites are carriers of many infectious and invasive diseases. Vector-borne tick-borne dis-Ixod mites are carriers of many infectious and invasive diseases. Vector-borne tick-borne diseases include borreliosis, viral encephalitis, anaplasmosis, ehrlichiosis, and babesiosis, which can be dangerous for both humans and animals. Babesiosis, caused by the blood parasite Babesia canis, is one of the most common protozoal diseases in dogs, causing significant economic and moral damage to service dog breeding and private owners. Carriers of Babesia canis are mainly imagos of ixod mites (family Ixodidae) of the genera Dermacentor and Rhipicephalus. Every year the habitat of ticks increases, and therefore the incidence of animals’ babesiosis increases. Invasive ixodid ticks play a major role in the transmission of this disease. The aim of the work was to study the infestation of ticks by babesia found on the territory of the Belgorod region in 2018-2019. The presence of babesia was determined by smears microscopy made from salivary glands, females’ eggs and a ticks suspension. The streptococci, enterobacteria, clostridia, borrelia and other microorganisms also were found in smears from salivary glands and from female ticks eggs. It was established that in the Belgorod district, the most common species are ticks of the species Dermacentor pictus. In spring, the degree of tick infected by babesia was higher than in autumn.

One of the problems of poultry farms includes parasitic diseases, in particular, ectoparasites, which lead to a decrease in productivity and weakening of the bird. Therefore, the aim of our research was to study the ectoparasites of chickens in the Udmurt Republic. For this, a clinical examination of poultry and chicken coops of private farm households was carried out in various regions of the republic. It was established that hens were kept in chicken coops with wooden floors and equipped nests and roosts. The bird was free-range. The invasion extensity in the southern regions of the Udmurt Republic was 98 %, in the central regions - 89 %, and northern - 78 %. The invasion intensity in the southern regions of Udmurtia was 4-5 specimens per 10 cm2, in the northern part this indicator was 1-2 specimens per 10 cm2. A relatively high percentage of poultry infection in the southern regions of the republic is associated with a warm mild climate. Red chicken ticks were found in all chicken coops, which is 100 % extensity of invasion

The issue of protecting farm animals from blood-sucking arthropods is especially relevant in modern conditions. Ixodid ticks cause great damage to agriculture, spoil leather raw materials, cause anemia during a mass attack, and milk yield decreases. Blood-sucking arthropods are dangerous reservoirs and carriers of many vector-borne diseases. On the territory of the Kaluga region, cases of anaplasmosis, babesiosis, nutthyliosis, and human borreliosis are recorded annually. Mosquitoes are also bloodsuckers, cases of dirofilariasis among people and dogs in recent years have been recorded in regions with a temperate climate, which indicates the migration of the parasite to northern latitudes. Moreover, mosquitoes are very annoying and cause concern in animals. Zoophilic flies and horseflies are also dangerous. The issue of timely preventive work is especially relevant in the warm season. The well-known ability of arthropods to develop resistance to many chemical compounds over a period of time forces us to conduct new scientific research with new combinations of chemical compounds. The article presents the results of production tests of new drugs based on s-fenvalerate and piperonylbutoxide in the form of a polymer material in the form of Flyblock ear tags and Flyblock solution based on cyflutrin against ixodic ticks, horseflies, zoophilic flies and mosquitoes on cattle in the Kaluga region. As a result, positive results were obtained for the insecticidal and by acaricide activity of the drugs. It is possible to actively implement them in practice for preventive purposes

In the phacoemulsification of cataracts to eliminate cells that form a secondary cataract in the postoperative period, mechanical polishing of the lens capsule is increasingly being used. In this regard, the aim of the study is to improve and evaluate the clinical eficacy of mechanical polishing of the lens capsule, determine the indications and contraindications for its use for the prevention of secondary cataracts in dogs with phacoemulsification. The control group consisted of 40 animals, a total of 48 surgical operations were performed, after which secondary cataract developed in 58.3 % cases. The experimental group where the prophylaxis method was applied comprised 14 clinical cases; secondary cataract in the postoperative period in this group developed in 21.4 % cases. The data obtained indicate the effectiveness of the studied methods. Complications associated with rupture of the posterior lens capsule, secondary glaucoma, uveitis, were not observed ather surgery with polishing the lens capsule. Thus, it was found that the technique has minimal risks of complications, is easy to use and does not require large financial costs.

The article is devoted to morphological changes in the tissues of chickens died during the associative course of mallophagosis and dermanissiosis. These diseases have become widespread in the Stavropol region. These ectoparasites can be carriers of a number of diseases dangerous to birds, such as salmonellosis, erysipelas, smallpox-diphtheria, pasteurellosis, borreliosis, etc. The presented ectoparasitoses cause significant damage to poultry farming in the region. To date, there are publications on the pathological changes in chickens that died during the associative course of these ectoparasitoses, but information on morphological changes is extremely scarce. The material for the work was the chickens died from the associative course of these ectoparasitoses in private farms of Shpakovsky, Grachevsky and Izobilnensky districts of the Stavropol region. 30 pathological autopsy autopsies of birds were carried out, from 5 of which the skin and internal organs were selected for histological examination, which was carried out according to the standard method. During a histological examination in chickens that died during the associative course of mallophagosis and dermanissiosis, the following changes were established: vacuolar liver dystrophy, parenchymal myocarditis, moderate spleen hypertrophy, chronic desquamative salpingitis, chronic dermatitis with focal hyperkeratosis, subacute desquamative enteritis, chronic interstitial orchitis

Rostov region and was examined in the Taganrog Interdistrict Veterinary Laboratory. In parallel with bacteriological studies, Petrifilm test plates were used to determine QMAFAnM. Milk samples were taken from each lobe of the udder during the morning milking. We examined milk in the first farm from 15 cows there were 60 samples. In the second farm, milk from 10 cows was examined there were 40 samples. In the first farm, in the study of milk from 15 cows by the bacteriological method, microorganisms were detected. Of the 60 milk samples, mesophilic aerobic and facultative anaerobic microorganisms (QMAFAnM), as well as somatic cells, were found in the 21st sample. Rapid test revealed a positive result in 10 samples of milk. Thus, the sensitivity of the rapid test is lower than bacteriological by 47.6 %. In the second farm, when examining milk from each udder share from 10 cows by the bacteriological method, mesophilic aerobic and facultative anaerobic microorganisms (QMAFAnM), as well as somatic cells, were found in 15 samples from 40 samples. Staphylococcus aureus was isolated in two milk samples. A positive result of the rapid test was obtained in 8 samples from 15 milk samples. The sensitivity of the rapid test was 53.33 %. Thus, the bacteriological method turned out to be more sensitive with the rapid test by 53.33 %. The results of the laboratory method and in parallel using the Petrifilm test plate coincided, but not in all samples, but only where the number of microorganisms was many times higher by the bacteriological method. The express method is specific, reduces the time of research.

Infectious bovine keratoconjunctivitis or moraxellosis is the most common cause of eye disease in cattle and related species. The object of the study was a new group of twelve europian bison from European zoos acclimatizing in the Shahdag National Park, Azerbaijan with the aim of further reintroduction there. The region is contaminated in cattle moraxellosis. An enzootic outbreak of infectious keratoconjunctivitis began three months after importation of animals during the period of maximum concentration of thies. The disease among the bison spread very quickly and was severe. The incidence was 83.3 %. Ather treatment of keratoconjunctivitis with two injections of Draxin at a dose of 1 ml/40 kg with an interval of 14 days the eight bison of ten animals recovered completely, two animals were blinded in one eye. It is recommended when importation nonimmune bison to regions that are disadvantageous on infectious keratoconjunctivitis, vaccination of animals during the quarantine. As soon as the quarantine period passes, it is necessary to drive off the bison to higher areas of the mountain forest and alpine glades, where there are fewer flies and the risk of diseases common to bison and cattle is reduces

The microorganism Macrorhabdus ornithogaster was discovered by Van Herck in 1984 and assigned to bacteria [1, 2], but later electron microscopic and molecular genetic studies of various authors have established its belonging to yeast according to the main characteristics of eukaryotes. Analysis of domestic and foreign scientific literature has shown that macrorhabdosis is a poorly studied disease of exotic and ornamental birds. The article summarizes and structured material on the spread of macrorhabdosis, intravital and post-mortem diagnosis and treatment of this disease. The results of studies by many authors indicate that the disease belongs to opportunistic mycoses, the microorganism is localized in many species of exotic and ornamental birds in the isthmus between the glandular and muscular stomachs, causing ventriculitis with the formation of ulcers and hypersecretion of mucus. At the same time, there is a lymphoplasmocytic infiltration of the own plate of the glandular stomach and isthmus, hypertrophy of goblet cells [3-8]. The disease occurs in acute and chronic forms and is manifested by malabsorption, regurgitation, diarrhea and progressive exhaustion [7-9]. Particular attention is paid to the methods of diagnosis of the disease, as well as methods of treatment. The microorganism is detected in the native feces specimen using microscopy [7, 10-12], smear smears of feces with their staining according to Gram or Romanovsky-Giemsa (Diff-Quik) [4, 13], as well as in the study of scrapings or swabs from glandular stomach. Data on new methods of indication and identication of the pathogen are presented, as well as treatment regimens for macrorhabdosis using antifungal drugs. Prevention of the disease is based on compliance with sanitary and hygienic standards of maintenance, proper feeding and timely treatment of concomitant diseases.

The aim of the study was to study the effect of a broad-spectrum antibiotic - enrofloxacin on the qualitative and quantitative composition of the intestinal microflora of honey bees. The experiments were carried out in two groups - experimental and control. In each group, 50 insects were examined. During the whole experiment, the bees in the control group were given regular sugar syrup. Bees in the control group were also given sugar syrup with a 10 % of antibiotic. Carbohydrate forage in both groups was given 3 times with an interval of 7 days. Before the start of the experiment and 24 hours ather the third feeding, the necessary microbiological and bacteriological studies were carried out to determine the amount and type of microflora in the bees intestines. It was found that carbohydrate feeding to the above scheme, namely sugar syrup with the addition of the enrofloxacin, promotes the development of signs of selective dysbiosis in the digestive tract of bees, which is manifested by the almost complete disappearance of the number of gram-positive and gram-negative bacteria and an increase of 0.4-0.7 lg CFU/g quantitative presence of yeasts and fungus