The purpose of the research is studying fauna of Coregonus sardinella parasites of the Indigirka River.

Materials and methods. The studies were carried out in August–September 2015–2017 in the lower reaches of the Indigirka River. A total of 421 specimens of C. sardinella were studied using partial parasitological autopsy method, of which: 227 specimens aged from 2+ to 12+ in 2015, 31 specimens aged from 4+ to 8+ in 2016, 163 specimens aged 2+ to 12+ in 2017. We used the determinant of parasites of fresh-water fish of the USSR fauna to determine the species affiliation of the revealed parasites. The infection intensity, and abundance index were assessed.

Results and discussion. 12 species of parasites were found in C. sardinella of the Indigirka River, namely, 1 species of protozoa, 4 species of cestodes, 3 – nematodes, 1 species of scrubs, 1 species of leeches, 2 species of parasitic crustaceans. Among the parasitic diseases of C. sardinella that are dangerous to human health, diphyllobothriosis is registered, and trienophorosis is among those that affects the marketable appearance of fish. High infection of C. sardinella with Diphyllobotrium sp. in the water area of the Indigirka River has been observed for several decades, which suggests its leading role in the circulation of this helminth in the studied reservoir. The study of the fauna of C. sardinella parasites show the need for continuous monitoring of fish infection rates to prevent possible epizootics and even death of juvenile fish.

The purpose of the research is studying features of daily activity of different blood-sucking mosquito species from the southern taiga subareas, and aspen and birch forests of the Tyumen Region woodland and forest-steppe zone.

Materials and methods. The researches were conducted in 2005–2015 in the south of the Tyumen Region in three natural environment and climatic areas (subareas), namely, the southern taiga, the aspen and birch forests, and the forest-steppe zone. The surveys were carried out in each of three subareas twice in the summertime, namely, in June and July. The census of biting mosquitoes was held using an entomological net with detachable sacs. An interval between the censuses held was 2 hours. The temperature, relative air humidity, wind velocity and precipitation were recorded simultaneously. In determining a species composition of the blood-sucking mosquito imago, special identification tables were applied; specific names were given in accordance with the current list of valid specific names.

Results and discussion. Blood-sucking mosquito number in the south of the Tyumen Region is high within 24 hours. The maximum number and a peak in species diversity were observed at 11 p.m. in all-natural environment and climatic areas of the Region. In studying a 24-hour rhythm, attacks by 29 mosquito species of the Culicidae family, which belong to five genera, namely, Anopheles, Culiseta, Coquillettidia, Aedes and Culex were detected. In terms of temperature, they can roughly be divided into two groups. The first group (10 species) includes species that attack actively at 10 to 20°С, and the second group (19 species) includes species that attack actively at 10 to 30°С. High flight activity of mosquitoes can be observed at 12.6–26°С, relative air humidity of 54–99% and light intensity of 0–8600 lux. Given night temperatures are relatively high, the main factor that limits mosquito night activity is fog occurrence with air humidity up to 100%. One of the limiting factors for mosquitoes is strong wind; when wind velocity was 5 m/sec, attacks by few individual mosquitoes were only detected. The female mosquito activity is influenced by their overall number – the higher the mosquito number is, the harder they find a feeder and receive required blood meal.

The purpose of the research is determining treatment and protective efficacy of modern drugs at eimeriosis in poultry under production conditions.

Materials and methods. The work was carried out in a laboratory for invasion diseases of farm animals and poultry of the Caspian Zonal Scientific Research Veterinary Institute, and in the Republic poultry farms. Using Fulleborn’s method, there were 500 excrement samples from chicken aged 1–3 months and laying hens tested, autopsy of 87 birds carried out, and morphological traits of their structure studied, based on which Eimeria tenella and E. necatrix were differentiated. The treatment and protective efficacy of Eimeterm 2.5% was tested in combination with Enrofloxacin in a dose of 3.0 ml per 1 liter of drinking water within 5–6 days. The drugs were given to floor housed broiler chickens with water to drink, namely, Eimeterm was given for two consecutive days in a dose of 7.0 mg/kg of bird weight (28 ml per 100 kg of bird weight), which is equal to 1 ml of the drug per 1 liter of drinking water within 48 hours, or 3 ml of the drug per 1 liter of drinking water which was given to a bird to drink for 8 hours in a day two consecutive days, and Enrofloxacin in a dose of 3.0 ml per 1 liter of drinking water within 5–6 days as compared to basic drug Amprolium. In another poultry house, test broiler chickens were administered 7.5 g of Amprolium 20% in powder form mixed with 1 kg of feed within 7–8 days. The therapeutic efficacy was evaluated by the results of coproscopic examinations and scrapes from different floor sections. A sample autopsy of chickens was carried out to find any morphological change in the digestive tract and Coccidia; intestinal mucosa swabs were tested using the Darling’s method, which was standardized by N. P. Orlov. The results obtained were processed statistically.

Results and discussion. The results of broiler chickens’ cecum examinations revealed a high rate of Eimeria infection. Thus, 20–30 oocysts were found in 55 samples in a single microscope field representing 63.2%. The oocysts referred to four species: Е. tenella, E. maxima and Е. mitis in the cecum and small bowel, and E. accervulina in the duodenum. 100% efficacy of Eimeterm 2.5% and Enrofloxacin when combined with water was confirmed. The mortality rate reduced from 137 to 11 animals per day. The survivability of broiler chickens in the test group in the growing period was 94.3%. The autopsy of broiler chickens showed no Eimeriosis-specific changes in the visceras. The tests of 200 cecum swabs and scatoscopy of 20 excrement samples found no Eimeria oocysts.

The purpose of the research is studying the epizootic situation on major helminthoses in cattle under different management systems in Georgia.

Materials and methods. The epizootic situation in Georgia on major helminthoses in cattle subject to management systems and the altitudinal zonation of areas location was studied by coprological examination of animals. In 2014–2018, the cattle aged over 2 years held on pasture from March-April until November was studied in homesteads of 59 districts. Similar studies were performed at 19 farms owned by limited liability companies, homesteads and entrepreneurs. The livestock there is presented by Schwyz and Holstein; all processes of care, feeding and milking are mechanized.

Results and discussion. Currently, the major helminthoses in pasture cattle in Georgia are paramphistomidosis, fasciolosis, dicrocoeliosis, gastrointestinal strongylatosis and dictyocaulosis which infect 67.5% of the examined cattle. Paramphistomidosis and fasciolosis are found in 59.7 and 21.5% of the examined cattle respectively. With increasing elevation of the altitudinal zonation, the paramphistomidosis and fasciolosis prevalence rates reduce. In case of paramphistomidosis, the infection ranges from 78.4% (low elevation from 0 to 200 m above sea level) to 23.9% (the subalpine area from 1901 to 2300 m above sea level), and in case of fasciolosis, 28.2–8.1% respectively. The rest species of helminths infected cattle to a lesser degree. Dicrocoelium sp. was found in 2.7% of animals, gastrointestinal Strongylata in 6.3%, and Dictyocaulus sp. in 3.9%. Paramphistomum spp., Fasciola sp. and gastrointestinal Strongylata infected 1.2% of the examined cattle in the farms with stabled cattle.

The purpose of the research is developing a method to collect pasture ticks where their number is small.

Materials and methods. The work was done in 2013–2016. The patent search was conducted according to the task and the search schedule. We found sufficient literature sources and protection documents on the investigated issue. Investigational studies were performed to design an instrument to collect pasture ticks.

Results and discussion. A method was developed to collect pasture ticks where their number is small. In order to do this, an instrument was designed which had a cylinder shape and was covered with a cloth called a drag. A rod was placed through the cylinder axle, having its ends connected to each other with a cord to drag the cylinder on the grass. Cylinder rotation when dragged through the grass brings the cloth in contact with ticks without being displaced in relation to one another. A patent of the Russian Federation was obtained under number No. 2544088 “Method for Collecting Ticks”.

The purpose of the research is studying microstructural changes in the process of adaptation of components during the formation of the “parasite–host” system by the example of Paramphistomum cervi (Zeder, 1790) parasitizing in the small intestine of spontaneously infected sheep.

Materials and methods. Peculiarities of changes in the microstructure of the small intestine in the “parasite–host” system were studied using parasitization of P. cervi in the intestines of sheep using well-known histological methods. Pieces of tissue of the small intestine of sheep with P. cervi, after being preserved in 70% alcohol, were processed according to the generally accepted histological procedure and embedded in paraffin. Sections 5–7 μm in thickness were stained with histological stains and examined under a light microscope.

Results and discussion. Microstructural analysis of the characteristics of the relationship in the "parasite–host" system showed that the mucous membrane of the small intestine of sheep in the presence of P. cervi looks sharply thickened. Swelling of the epithelium of villi and crypts, its vacuolization and albuminoid degeneration were found. In some places, proliferation of the epithelial layer of the mucous membrane was detected, due to which epithelial hyperplasia is observed, in some cases turning into metaplasia. Proliferation and hyperplasia (metaplasia) in the endostation of the host in the presence of the parasite contribute to: 1. stability of the parasite-host system and the participation of trematodes in trophism; 2. determination of the clinical and morphological picture of trematodose; 3. predicting the effects of this pathology on the host. Adhesion in the microstructural complex “trematode tegument – epithelial tissue of the villi of the small intestine” in ovine paramphistomosis at the contact level of two glycocalyx layers – the tegument of P. cervi and the surface of the epithelial cells of the villi of the host’s intestine, as well as single histological staining of the sites of contact between the parasite and the host as a result of mixing the components of the trematode tegument and the tissue of the host’s small intestine with deep adhesion indicate the established mutual relations between the components of a single system "parasite–host".

The purpose of the research is comparing structural changes in the liver of rabbits with biochemical parameters at opisthorchosis under experimental conditions.

Materials and methods. Laboratory studies included a biochemical blood test to determine the amount of alanine aminotransferase (ALT), aspartate aminotransferase (AST) as the main markers of inflammation and their ratio, lactate dehydrogenase (LDH (total)), creatine kinase – CPK-MF (muscle), and uric acid. Morphological changes in the liver were determined using light microscopy and analysis of a macroscopic pattern. Histological sections of the liver were stained with hematoxylin and eosin, and according to Van Gieson (to identify the degree of proliferation of connective tissue).

Results and discussion. A biochemical study obtained an excess of KFK-MV by 1.93 times, and LDH by 5.4 times in infected animals. The amount of uric acid was within normal limits. AST and ALT were within normal limits, but the ratio confirmed the inflammatory process. Macroscopic examination revealed fibrosis of the edge of the hepatic lobes in the form of a tape. Microscopic examination revealed a sectoral lesion of the liver parenchyma with loss of cytoarchitectonics and proliferation of connective tissue between the lobules. Hepatocytes lying on the periphery of the lobes had more pronounced structural changes compared to the central ones. Segregation of cytoplasmic glycogen granules and nuclear swelling were noted in the cytoplasm of peripherally located hepatocytes. Thus, changes in the liver that occur during opisthorchosis at the cellular and tissue levels are confirmed by an increase in individual biochemical parameters and morphological changes in the liver, as one of the central organs of biochemical processes.

The purpose of the research is to study the acute oral toxicity of the supramolecular complex of ivermectin.

Materials and methods. The object of the study was laboratory animals kept in the vivarium of the All-Russian Scientific Research Institute of Fundamental and Applied Parasitology of Animals and Plants. The preclinical study of the ivermectin complex was carried out in accordance with “Guidelines for the Experimental (Preclinical) Study of New Pharmacological Substances”. To process the experimental data in the study of the supramolecular complex of ivermectin, the method proposed by Litchfield and Wilcoxon modified by Z. Roth was used. Acute oral toxicity was carried out with the administration of a complex of ivermectin and the substance ivermectin into the stomach for control in high doses in white mice and rats with a live weight of 18 and 160–180 g respectively. For each dose, 10 mice and 6 rats were used. The drug was administered once using a gastric tube in a doses from 40 to 350 mg/kg in terms of AS. For 14 days the general condition and behavior of animals, possible death, as well as the manifestation of symptoms of intoxication has been monitored.

Results and discussion. As our studies showed, the picture of intoxication in both species (mice and rats) was comparable, and the dependence of the number of dead animals on the administered dose was also revealed. Unlike the substance ivermectin, the toxicity of the supramolecular complex is 3 times lower. The introduction of arabinogalactan into the composition of the drug helps to level the negative effect of AS (ivermectin) in the supramolecular complex preparation on the animal organism. LD50 of ivermectin substance for mice was 82.0, for rats – 165.0 mg/kg, supramolecular complex of ivermectin – 280.0 and 298.0 mg/kg respectively (according to the drug 14500 and 14598 mg/kg). According to GOST 12.1.007-76, the supramolecular complex of ivermectin belongs to hazard class 4.

The purpose of the research is to evaluate the acute toxicity of Altric-Extra when introduced into the stomach to mice and rats.

Materials and methods. The studies were conducted in the vivarium of the All-Russian Research Institute of Fundamental and Applied Parasitology of Animals and Plants. The acute toxicity of Altric-Extra was determined on 20 white outbred male mice weighing 19.3–23.3 g, 10 animals in a group and on 30 white outbred male rats weighing 150–196 g, 6 animals in a group. Altric-Extra was administered to mice of the experimental group once into the stomach in the form of a suspension in a dose of 5,986 mg/kg at the rate of 0.2 ml/10 g of body weight. Altric-Extra rats were also administered once into the stomach in the form of a suspension at the rate of 2.0 ml/100 g body weight. As a carrier in the preparation of the suspension, 1% starch gel was used. The experimental rats of groups 1, 2, 3 and 4 were given Altric-Extra at doses of 4,580.2 mg/kg, 3,846.2; 3,088.8 and 1,577.9 mg/ kg respectively. Mice and rats of the control groups were administered once with 1% starch gel. For 14 days, the behavior and condition of the animals was monitored. The body weight of the experimental animals was measured on the 1st, 3rd, 7th, 9th and 14th days of the experiment.

Results and discussion. Medium lethal doses of LD₅₀ have been established for oral administration to laboratory animals. For mice, the LD₅₀ was more than 5 986 mg/kg, i.e., according to the generally accepted hygienic classification, Altrick-Extra belongs to hazard class 4 (low-hazard substances). On rats, the LD₅₀ was 3 103.1±48.5 mg/kg (2,354.6÷3,851.5 mg/kg). Therefore, Altrik-Extra belongs to hazard class 3 (substances are moderately hazardous).

The purpose of the research is studying the effect of mechanochemical technology on anthelmintic efficacy of supramolecular complexes of fenbendazole with licorice extract.

Materials and methods. Tests of the supramolecular complexes of fenbendazole (SMCF) with licorice extract (LE) were carried out on 127 heads of young sheep spontaneously infected by Nematodirus sp. and other types of gastrointestinal strongylates. For each helminthosis, animals of different groups of 8–11 animals each were given single oral administration of SMCF with LE in a dose of 2.0 mg/kg in AD in the form of 10 and 17 % powders and 2.4 and 4.5% suspensions in comparison with the basic drug – fenbendazole (FBZ) in a dose of 2.0 mg/kg. SMCF with LE was developed according to mechanochemical technology for 2 hours. The baseline was a group of sheep that did not receive the drug. The anthelmintic efficacy of the preparations was taken into account according to the results of coproovoscopic studies of sheep by flotation before and 16 days after the preparations were used. Accounting for the effectiveness of drugs was carried out according to the "control test" type.

Results and discussion. SMСF with LE in a dose of 2.0 mg/kg by AD in the form of 10 and 17% powders and 2.4 and 4.5% suspensions showed respectively 89.2; 83.12; 82.09 and 83.59% effectiveness against Nematodirus spp. and 88.73; 67.3; 83.87 and 86.38% activity against other types of Strongylata when receiving 22.7 and 21.9% effect of the base drug – FBZ.

The purpose of the research is studying anthelmintic efficacy of fenbendazole solid dispersion obtained by mechanochemical technology with various components for targeted delivery.

Materials and methods. The tests were conducted on 80 white mice infected experimentally with Trichinella spiralis and 145 sheep infected spontaneously with gastrointestinal nematodes. In case of each helminthosis, animals in different groups of 8–10 units each were given, orally, as a single dose, a fenbendazole solid dispersion (FSD) with polyvinylpyrrolidone (PVP), arabinogalactan (AG), glycyrrhizinic acid sodium salt (NaGA), dioctylsulphosuccinate sodium (NaDSS), licorice extract (LE) and hydroxyethylstarch (HES) in a dose of 2.0 mg/kg of the active ingredient as compared to fenbendazole drug at 2.0 mg/kg. A group of animals that were not given the drug was a control group. Anthelmintic activity of the preparations was considered based on dissection of the mouse small bowel and data from the sheep coproovoscopic examination carried out by the flotation technique before and 15 days after application of such drugs.

Results and discussion. FSD with PVP, AG, NaGA, NaDSS, LE and HES in a dose of 2.0 mg/kg of the active ingredient (fenbendazole) showed 100; 98.7; 99.8; 100; 96.8 and 95.3% activity in mice against T. spiralis respectively; in sheep – 100; 96.3; 98.0; 100; 94.6 and 93.8% effectiveness against Nematodirus spp., and 100; 97.5; 98.6; 100; 97.0 and 96.5% activity against other species of the gastrointestinal Strongylata at 22.6–27.2% effectiveness of the main drug, namely, the active ingredient fenbendazole.

The purpose of the research is development of preventive measures against zooanthroponoze vector-borne diseases spread by parasitic arthropods in the Kaluga Region.

Materials and methods. The subject of the research was Ixodidae, mosquitoes, and small mammals inhabiting the Kaluga Region. The census of parasitic arthropods was carried out on the territory of all districts of the Kaluga Region and the city of Kaluga. Open natural habitat and human settlements were investigated. Weather conditions from 2013 to 2018 were also taken into account. For the purposes of the study, we used standard methods for capturing and counting arthropods and mouse-like rodents. In order to obtain mathematical models of small mammal populations, a full factorial experiment was conducted using the collected statistical data. In-process testing of the drug based on s-fenvalerate and piperonyl butoxide were carried out under the conditions of the agricultural collective farm “Niva” of the Kozelsky District, the Kaluga Region, and LLC “Angus Center of Genetics” of the Babyninsky District, the Kaluga Region.

Results and discussion. In the Kaluga Region, two species of ixodic ticks are found, namely, Ixodes ricinus and Dermacentor reticulatus, which have two activity peaks. Mosquito may have 3-4 generations in a year in the Kaluga region. The most common mosquito species in the Kaluga Region are Aedes communis, Ae. (Och.) togoi and Ae. (Och.) diantaeus, Culex pipiens Culex Linnaeus, 1758 (Diptera, Culicidae) (Culex pipiens): Cx. pipiens f. pipiens L. (non-autogenic form) and Cx. p. f. molestus Fors. (autogenic form), which interbreed, and reproductively isolated in the Region. The developed mathematical models make it possible to quantify the risks of outbreaks of zooanthroponoze vector-borne diseases without the cost of field research, and allow for rational, timely and effective preventive measures. Medications based on s-fenvalerate and piperonyl butoxide and based on cyfluthrin showed high insecto-acaricidal efficacy and safety.

The purpose of the research is to test the effectiveness of the supramolecular complex of albendazole and triclabendazole (Altric-Extra) in case of fasciolosis and nematodoses of the digestive tract of sheep under production conditions.

Materials and methods. The test of the effectiveness of Altrik-Extra was carried out in the North Caucasus Federal District of the Chechen Republic in July 2019 on 205 sheep of the Tushino breed, spontaneously infected by gastrointestinal nematodes and Fasciola sp. Sheep infection with helminths was established by fecal examination by Fülleborn using ammonium nitrate. The average number of helminth eggs in 1 g of feces was determined using a VIGIS camera. Altric-Extra was given at a dose of 5 mg/ kg of AS (2.5 mg of albendazole and triclabendazole respectively) or 50 mg/kg in the preparation in a mixture with mixed feed by the group method. The effectiveness of the drug was determined by the results of fecal studies 14 and 25 days after deworming. After giving the drugs for three days, the clinical condition of the experimental sheep was monitored. Altric-Extra effectiveness was evaluated using the “critical test” method according to the Guidelines approved by the World Association for the Progress of Veterinary Parasitology (1995).

Results and discussion. The Altric-Extra supramolecular complex in a therapeutic dose of 5.0 mg/kg of AS (for the preparation of 50 mg/kg) was 100% effective against gastrointestinal nematodes and Fasciola sp. of sheep. The sheep ate a mixture of the preparation with mixed feed; it is convenient to set in a group method; side effects after deworming is not observed.

The purpose of the research is to compare the effectiveness of the supramolecular complex of albendazole with basic albendazole at toxocarosis in laboratory mice to evaluate the potential prospects of a new drug in treatment of tissue Toxocara sp. infection.

Materials and methods. The study used 75 female BALB/c mice. All mice were infected with infective Toxocara canis eggs by oral gavage once, by 800 infective eggs each. The mice in the test groups were given base albendazole (ABZ) and improved albendazole (ABZ-DDS) in a doses of 50 to 200 mg/kg. The mice in the control group were given distilled water of 50 mcl within the same time limits. T. canis eggs were cultivated to rear their infective stages in Petri dishes in a thermostat at 25 °С. ABZ and ABZ-DDS suspensions were prepared using distilled water and Tween-20 in proportions required to obtain necessary concentrations. The drug was given to mice by oral gavage in the amount of 0.2 to 0.5 ml per mouse. In order to separate and count Toxocara sp. larvae, the muscular tissue was minced and digested in the simulated gastric fluid (SGF) for 50 minutes in a ‘Gastros’ apparatus at 37 °С. The visceras, namely, liver, lungs, heart, kidneys and brain were minced and placed on a sieve into the SGF solution for 4 hours at 37 °С. The microscopy and counting of larvae were carried out using a microscope.

Results and discussion. As of the 20th day after the infecting, the ABZ and ABZ-DDS efficacy was 59.25 and 65.82%; 66.95 and 69.70%; and 69.35 and 76.48% in a doses of 50, 100 and 200 mg/kg respectively. As of the 40th day after the infecting, the ABZ and ABZ-DDS efficacy was 66.54 and 70.87%; 68.03 and 73.41%; and 74.45 and 75.88% in a doses of 50, 100 and 200 mg/kg respectively. The number of T. canis larvae reduced in the mouse brain when the ABZ-DDS was applied in a doses of 100 and 200 mg/kg. There were not significant differences in the results of the therapy in different periods after the infecting (on the 20th and 40th day). As the dose was increased, the ABZ and ABZ-DDS efficacy was enhanced significantly.