The purpose of the research is to study ixodid fauna and the distribution of some species to take timely and effective measures against ticks.

Materials and methods. In the Nakhchivan Autonomous Republic, we examined 14,207 domestic animals of 8 species of which 5,512 (38.8%) were found to be infected with ticks. 30,025 specimens of ixodid tick’s imago were collected from the animals. The collected material was examined at the Laboratory of Veterinary Medicine of the Nakhchivan State University and the Laboratory of Parasitology of the Nakhchivan Scientific Center of Veterinary Medicine. The ticks were identified using the identification guide by N. A. Filippova.

Results and discussion. The parasitism of 16 species of ixodid ticks of four genera was recorded in the domestic animals in the Nakhchivan Autonomous Republic, namely, Hyalomma, Rhipicephalus, Dermacentor, and Haemaphysalis. Fifteen parasite species were found on the body of the livestock animals, of which 4 species, Hyalomma asiaticum, H. anatolicum, Rhipicephalus bursa, and Dermacentor marginatus were dominants. The H. anatolicum range occupied almost the entire Nakhchivan Autonomous Republic and made up 25.7% of the total and 44.4% of the tick gender collection. H. anatolicum is considered to be the dominant in terms of distribution.

The purpose of the research is to study the distribution of the nematode Capillaria paranalis in wild carnivores in the Central region of the European part of Russia and to evaluate histopathological changes in the anal glands.

Materials and methods. The anal glands were examined during helminthological autopsies of 25 pine martens (Martes martes) and 43 foxes (Vulpes vulpes) from hunting grounds in the Ryazan and Tver regions. The material for histological examination was fixed in 10% formalin, sections were stained with Mayer’s Hematoxylin-Eosin.

Results and discussion. C. paranalis nematodes were found in the anal glands of 16 (64%) martens in number from 2 to 11, averaging 6 specimens, with an abundance index (AI) of 3.8 specimens. Nematodes were found in 5 (12%) foxes in number from 1 to 3, averaging 2.2 specimens, with an AI of 0.3 specimens. Histological examination showed that nematodes in the anal glands are located parietal and within the stratum corneum of the mucosa. Bilateral sacculitis is moderately expressed, the process is chronic. In the places of nematode location, the epithelium is degeneratively changed. Soft tissues surrounding the anal glands are edematous, there are clusters of small lymphocytes, less often histiocytes and macrophages, sometimes neutrophils, eosinophils and plasma cells are visible.

The purpose of the research is a comparative analysis of the dynamics of helminth and protozoan infections in domestic dogs in Perm for 2020 to 2023.

Materials and methods. The study was conducted at the Department of Infectious Diseases of the Faculty of Veterinary Medicine and Zootechnology of the Perm State Agro-Technological University. The material for the study was 1,439 fecal samples and 2,141 whole blood samples from domestic dogs admitted to private veterinary clinics in Perm. Feces were collected three times to containers with the Turdyev preservative and examined using the combined Kotelnikov-Khrenov method and sequential washing. Venous blood was collected to test tubes with EDTA K3 and analyzed for microfilaria using the V. Yastreb method. The results underwent common statistical processing.

Results and discussion. The infection prevalence (IP) in dogs increased slightly from 18 to 20% in 2020–2023 but remained relatively stable as compared to 2015–2019. When studying seasonality, two infection peaks were observed, in spring (March-April) and autumn (September and November). The following helminths and protozoa with direct development cycles occupied the leading place among intestinal parasites: Giardia duodenalis, 2.43% (35); Toxocara canis, 3.33% (48); Cystoisospora spp., 3.13% (45); C. canis, 1.81% (26); and sarcosporidia Sarcocystis sp., 2.02% (29). Microfilaria infection rate in dogs was 1.5% in 2022–2023 without pronounced seasonality. In general, the situation on parasitic diseases in dogs has remained tense in Perm over the past three years.

The purpose of the research is to study the spread of intestinal protozoa in dogs and cats in the territory of Moscow.

Materials and methods. In 2020–2022, 3,411 fecal samples were analyzed: 2212 from dogs, including 994 samples from puppies, and 1199 samples from cats, including 465 from kittens. All animals included in the experiment were kept at home. The feces were examined by native microscopy and the flotation method using a zinc sulfate (ZnSO4) solution with a density of 1.24 g/cm3.

Results and discussion. The results of the study showed that the most common in dogs are Giardia duodenalis – 9.27% (205 positive samples out of 2212), Sarcocystis sp. – 3.8% (84/2212), less frequently recorded Cystoisospora sp. – 2.58% (57/2212), Cryptosporidium sp. – 2.49% (55/2212), Cystoisospora canis – 1.13% (25/2212), Sarcocystidae gen. sp. – 0.3% (7/2212), family Trichomonadidae – 0.27% (6/2212). In 15.5% of cases, intestinal protozoan diseases in the form of monoinfection were registered in dogs. Among mixed infections, the most frequently recorded were G. duodenalis and C. canis – 0.5% (10/2212) and G. duodenalis and Cryptosporidium sp. – 0.3% (7/2212). In cats, the prevalence rates of protozoan infection were: Giardia duodenalis 5.5% (66/1199), Cryptosporidium sp. – 4.17% (50/1199), fam. Trichomonadidae – 2.67% (32/1199), Cystoisospora felis – 1.33% (16/1199), Sarcocystis sp. – 0.42% (5/1199), Cystoisospora rivolta – 0.25% (3/1199), Sarcocystidae gen. sp. 0.17% (2/1199). In cats, the most common combinations of two protozoan species were: G. duodenalis and Cryptosporidium sp. – 0.5% (6/1199), G. duodenalis and fam. Trichomonadidae – 0.4% (5/1199). With the age of the animal, both cats and dogs experience a decrease in infection with G. duodenalis and Cryptosporidium sp., cats also experience a decrease in infection with C. felis, and dogs experience a decrease in infection with protozoa of the fam. Trichomonadidae, C. canis and Cystoisospora sp.

The purpose of the research is to study the epizootic situation on arachnoentomosis of dogs in Stavropol.

Materials and methods. In total, 2,296 dogs with skin lesions were examined in medical clinics in 2021 to 2023. Of these, 1,539 had dermatitis of parasitic etiology. Acarosis was diagnosed from epizootic data, clinical picture analysis, and skin examinations by inspection analysis using the express method and microscopic examination of skin scrapings in case of deep lesions. We analyzed veterinary reporting data in Stavropol for 2021–2023.

Results and discussion. It was found that parasitic dermatitis occurred annually in 490–510 dogs; helminthosis, in 150– 190 animals; and protozoa, in 190–210 dogs. During periods of abrupt changes of weather, the number of sick animals increased. Skin diseases caused by fleas progressed most, followed by dermatitis caused by itch mites of the genus Demodex, Sarcoptes, and Otodectes, and then ixodid ticks.

The purpose of the research is to analyze the literature devoted to the study of one of the factors in the development of resistance of parasitic nematodes to anthelmintic drugs which has a genetic basis.

The article analyzes the role of genetic mutations identified in populations of parasitic nematodes in vertebrates that do not show sensitivity to benzimidazoles, macrocyclic lactones and acetylcholinergic agonists and antagonists. The literature shows that benzimidazole resistance in parasitic nematodes, by the example of the nematode Haemonchus contortus, is associated with mutations in the β-tubulin encoding isotype 1 gene gru-1, which is a target for benzimidazoles in the body of nematodes. For the nematode resistance to macrocyclic lactones which are glutamate receptor agonists, it was shown by the example of the nematode Caenorhabditis elegans that mutations of three glc-1, avr-14, and avr-15 genes that encode the α-type subunits of glutamate-gated chloride channels of receptors give rise to the development of nematode resistance to macrocyclic lactone ivermectin. Parasitic nematode resistance to cholinergic anthelmintics (levamisole, pyrantel, oxantel), by the example of the nematode Ascaris suum, is associated with mutations in the Asu-UNC-29 and Asu-UNC-38 subunit-encoding genes which form three types of nicotinic acetylcholine nematode receptors, N, L and B. The significance of nematicide resistance as a phenomenon in plant parasitic nematodes has not yet been fully resolved. The phytonematode ecology and biology allow them to survive unfavorable conditions of existence. There are few studies evidencing the probability of detecting resistance in phytoparasitic nematodes to chemical means of protection. Studies are actively conducted to search genetic markers of resistance to various nematicides on the model free-living nematode C. elegans, which will allow us to create new nematicides against both zooparasitic and phytonematodes.

The purpose of the research is to evaluate embryotoxic and teratogenic effects of the supramolecular complex of ivermectin aniverm-2.0%.

Materials and methods. The experiment was conducted on 100 female rats weighing 180–200 g that were kept in the vivarium of the VNIIP – FSC VIEV. The experimental rats were divided into groups of 8 animals each. The supramolecular complex of ivermectin aniverm-2.0% was administered to inbred pregnant female rats orally in the suspension formulation using an intragastric catheter three times in increased doses. The 1st group pregnant females were administered a total dose of aniverm-2.0% for the first 6 days which was 3 times higher than the therapeutic dose (3.6 mg/kg) by the active substance, and 180 mg/kg by the drug. The 2nd group animals were given the ivermectin substance in a similar dose of 3.6 mg/kg in the suspension formulation on starch paste on the first day of pregnancy. The 1st group rats were given a total dose of aniverm-2.0% increased to 3-fold, equal to 7 days (7–13 days), at a dose of 4.2 mg/kg by the active ingredient, and 210 mg/kg by the drug, and the 2nd group rats received a similar dose of the ivermectin substance of 4.2 mg/kg in the suspension formulation on starch paste on day 7 of pregnancy. On day 14 (days 14–19), the 1st group rats were administered a total dose of aniverm-2.0% for 6 days for the third time at a dose of 3.6 mg/kg by the active ingredient, and 180 mg/kg by the drug, and the second group of animals received the substance of ivermectin at a dose of 3.6 mg/kg by the active ingredient in the suspension formulation on starch paste. The female rats from the 3rd control group were administered starch paste of 5–7 mL three times during the same periods of pregnancy as the experimental animals. On day 20 of embryogenesis, all experimental rats were euthanized. In the females, after slaughter and extirpation of the uterus, the number of embryos, resorptions, and corpus luteum in pregnancy in both ovaries was recorded; the craniocaudal embryo dimensions were measured, their weight was recorded, and their sex was determined. The placenta was measured and weighed to calculate the fetoplacental coefficient. Attention was also paid to deformities and developmental anomalies in the embryos. Some of the fetuses were then placed in Bouin's fluid for further examination of the internal organs using the Wilson method. Another part was fixed in 96.0% alcohol to examine the skeletal system and measure bone length using the Dawson method. To assess embryotoxic effects of the drug, preand post-implantation death and total embryonic mortality were recorded. The obtained results were processed statistically.

Results and discussion. In the entire pregnancy period, no signs of intoxication were observed in the animals. The animals were active, ate food readily and gained weight well. Macroscopic examination of the internal organs did not reveal any pathological changes. There were no signs of inflammation, deformities or other abnormalities in the embryos and placentas. Aniverm-2.0% in a three-fold increased dose of 0.6 mg/kg with intragastric administration did not exhibit embryotoxic or teratogenic effects in critical periods of embryogenesis.

The purpose of the research is to assess the acute toxicity in laboratory animals of experimental samples of two antiparasitic combined drugs from the group of avermectins and pyrethroids, conventionally designated as CA-17 and CA-18 (NBC Pharmbiomed LLC).

Materials and methods. The present experiment was performed on sexually mature outbred rats and mice (males), to which the studied drugs were administered in two ways, intragastrically and subcutaneously, in a dose range that allows calculating the parameters of acute toxic effects or setting the maximum tolerated dose. The studied preparations were transparent oily liquids containing avermectin C and cyfluthrin in different concentrations. During 14 days, the condition and behavior of the animals were monitored, death and symptoms of intoxication were recorded. Probit analysis was used to calculate LD50 values and other parameters of acute toxic effects of drugs.

Results and discussion. The ЛД50 value of CA-17 when administered intragastrically to rats and mice is 6072 (5208 6975) and 4008 (2340 6094) mg/kg, respectively. The ЛД50 value of CA-18 when administered intragastrically to rats and mice is 3716 (3103 4496) and 2929 (1454 3603) mg/kg, respectively. Compared with rats, mice have a species sensitivity to both drugs. Preparations CA-17 and CA-18 for intragastric administration according to the hygienic classification belong to hazard class 3. The ЛД50 value of CA-17 after cutaneous administration to rats and mice is more than 7,500 mg/kg, respectively. Similar indicators for CA-18 for rats and mice are more than 5,000 and 2,500 mg/kg, respectively. According to the parameters of cutaneous toxicity, both drugs belong to hazard class 4.

The purpose of the research is to study the anthelmintic efficacy of complex solid dispersion of fenbendazole (FBZ) and niclozamide (NZM) against monieziosis and gastro-intestinal nematode infection of sheep.

Materials and methods. A complex solid dispersion was obtained by mechanochemical processing of FBZ, NZM and polyvinylpyrrolidone (PVP) substances in a ratio of 2 : 20 : 78 in LE-101 roller mill at an energy intensity level of 1 g for 4 hours at drum rotation speed of 60–70 rpm. The activity of the complex solid dispersion was studied on 119 sheep naturally infected with Moniezia expansa and gastro-intestinal strongyles. The sheep were divided into 3 groups for each disease. The complex solid dispersion was administered to the sheep of the first experimental groups once orally at a dose of 20 mg/kg of NZM against monieziosis and at a dose of 2 mg/kg of FBZ against gastro-intestinal nematode infection. The sheep of the second experimental groups received a mechanical mixture of FBZ, NZM and PVP in the same ratio in similar doses. The sheep of the 3 groups served as a control and did not receive any preparations. The efficacy of the drugs was calculated on the results of coproovoscopic studies using the flotation method before and 15 days after deworming according to the "control test".

Results and discussion. The results of trials of complex solid dispersion against sheep helminthosis indicated 97.0% efficacy of the drug at a dose of 20 mg/kg of active substance (NZM) against monieziosis and 92.1% efficacy against gastrointestinal nematode infection at a dose of 2 mg/kg of FBZ. The basic drug – a mechanical mixture of FBZ and NZM in the same doses revealed 25.2–26.4 % efficacy.

The purpose of the research is to obtain 5% toltrazuril supramolecular forms with the addition of SASs and emulsifiers, and to study antiprotozoal activity in a limited period of their introduction into the poultry diet with water.

Materials and methods. Toltrazuril supramolecular forms were obtained by the mechanochemical suspension method with the addition of auxiliary excipients (emulsifier, SASs, etc.). A mixture consisting of following three types of coccidia of chickens was used to infect the chickens: Eimeria acervulina, E. tenella, and E. maxima. The following drugs were tested: Stop-coccid 2.5%, Supramolecular Toltrazuril 5% with SASs, Supramolecular Toltrazuril 5% with Emulsifier, and Toltrazuril 5%. Six groups (two control and four experimental) of 7 broiler chickens aged 15 days were formed. The chickens from one control and four experimental groups were infected with a mixture of sporulated coccidia oocysts. The reproduction level of coccidia oocysts excreted by one chicken and in 1 g of droppings from the experimental chickens was calculated during the 5-day patent period. The birds of each group were weighed at the beginning and the end of the experiment. The intense-effectiveness of the drug and the reproductive index were calculated. A diagnostic dissection of the forcedly killed birds was performed.

Results and discussion. It was found that Supramolecular Toltrazuril 5% with SASs and Supramolecular Toltrazuril 5% with Emulsifier gave the most reduced reproduction of coccidia oocysts in experimental coccidiosis as compared to the other experimental groups. The intense-effectiveness of these drugs was the highest as compared to the other groups.

The purpose of the research is to study the anthelmintic efficacy of complex solid dispersion of fenbendazole and niclozamide against dictyocaulosis and trichuriosis of sheep.

Materials and methods. The complex solid dispersion was obtained by mechanochemical processing of fenbendazole (FBZ), niclozamide (NZM) and polyvinylpyrrolidone (PVP) substances in the ratio of 2 : 20 : 78. The obtained samples of solid dispersion were studied for nematocidal activity on sheep naturally infected with Dictyocaulus filaria and Trichuris ovis. The solid dispersion was tested against dictyocaulosis of sheep at a dose of 2 mg/kg and against trichuriosis at doses of 2, 4 and 6 mg/kg according to FBZ.

Results and discussion. The complex dispersion based on FBZ, NZM and PVP showed 98.9% efficacy against dictyocaulosis of sheep at a dose of 2 mg/kg according to FBZ. The basic preparation – a mechanical mixture of FBZ and NZM at the same dose revealed 25.8% effect. Against trichuriosis of sheep, 98.7; 93.5 and 78.8% efficacy of complex solid dispersion was obtained at doses of 6, 4 and 2 mg/kg according to the active substance, respectively. The mechanical mixture of FBZ and NZM showed a 24.6% effect at a dose of 6 mg/kg according to FBZ. The dose of the complex solid dispersion – 6 mg/kg according to FBZ is recommended as therapeutic against trichuriosis of sheep.

The purpose of the research is to evaluate the efficacy of the combined use of fenbendazole and Bacillus amyloliquefaciens against Strongylata in horses, to compare the combined therapy to fenbendazole monotherapy, and to study the effect on the general clinical state of horses.

Materials and methods. The study was conducted on 20 horses divided into two groups of 10 animals. The horses from the experimental group were given fenbendazole once at a dose of 7.5 mg/kg, and the probiotic B. amyloliquefaciens daily at a dose of 50 mg/kg for 14 days. The control group of horses received only fenbendazole. The therapy efficacy was monitored by examining faeces using the flotation method on days 7, 10, 14, 16, 19, 22, 25, 28, 31, and 34 after treatment. On day 14 of the experiment, the test reduction rates in the number of eggs in faeces were calculated. To determine starting dates of repeated egg release, the values obtained on days 7 and 14 were used. Faecal microbiota was analyzed before the treatment and on day 14.

Results and discussion. Both groups of horses showed a reduction in Strongylata eggs in faeces after treatment with a gradual increase in their number by day 34 of the experiment. The first Strongylata eggs were detected on day 7 of the therapy. The period of repeated release of Strongylata eggs was two weeks in the experimental and control groups. Test reduction rates of eggs in faeces were below 90% on day 14 in both groups. The analyzed faecal microbiota did not reveal significant changes after the probiotic, although Aspergillus fungi disappeared in the experimental horses. Throughout the study, the horses in both groups remained clinically healthy with no signs of gastrointestinal disorders. The combined fenbendazole and B. amyloliquefaciens did not result in any statistically significant increase in the deworming efficacy as compared to fenbendazole alone (P > 0.05). However, the combined anthelmintic and probiotic showed a certain biological advantage expressed in a decrease in Strongylata eggs after the treatment in the experimental group. Despite the lack of significant changes in the intestinal microbiota, the absence of Aspergillus spp. after administered probiotic may indicate its potential antifungal effect.

The purpose of the research is to test the supramolecular complex of ivermectin Aniverm-2.0% by free feeding of the drug mixed with concentrated feed against gastro-intestinal strongylatosis of the deer.

Materials and methods. The test of the supramolecular complex of ivermectin Aniverm-2.0% against gastro-intestinal strongylatosis of semi-wild animals was carried out from November 2023 to April 2024 in the reserve of the country residence of the head of the Chechen Republic, where more than 200 marals, sika deer and roe deer were kept. 40 fresh fecal samples were collected from the ground in December 2023. The fecal samples were examined in the biology laboratory of the Ibragimov Integrated Research Institute of the Russian Academy of Sciences by the Fülleborn flotation method using a saturated sodium chloride solution and the method of successive washes to detect elaphostrongyl larvae. Aniverm-2.0% was fed at a dose of 0.3 mg/kg mixed with concentrated feed by the group method; evenly poured into 4 feeders for 200 deer. The efficacy of the drug was taken into account by the "critical test" after 10 days and 4 months after deworming.

Results and discussion. In the feces of deer, strongylata eggs were found in 23 out of 40 samples (EI = 57.5%) with an average of 88.9±2.74 egg sp. detected in 1 g of feces. Elaphostrongyl larvae were not detected. Dicrocoelium spp. eggs were found in 8 samples. After deworming of marals, red deer and roe deer with Aniverm-2.0% at a dose of 0.3 mg/kg by active ingredient (0.15 mg/kg by the drug) by the group method mixed with compound feed, strongylata eggs of the digestive tract were not found in the feces after 10 days and for 4 months after treatment. 100% therapeutic and prophylactic efficacy of the drug was established. The animals willingly ate the drug with food, no side effects were noted after administration of the drug.

The purpose of the research is to investigate the resistance of Pinus sylvestris, P. sibirica and Larix sibirica pine seedlings to the nematode Bursaphelenchus xylophilus to assess the potential risk of death of these conifers from pine wilt disease.

Materials and methods. In the experiment, 8-year-old seedlings of P. sylvestris, P. sibirica and 4–5-year-old seedlings of L. sibirica were used in an amount of 16 seedlings of each species (8 B. xylophilus-infected plants and 8 control plants).

Results and discussion. Pines Pinus sylvestris, P. sibirica and L. sibirica were susceptible to the pine wood nematode B. xylophilus. All plants died by the end of the study, but the most rapid wilting and death of plants was observed in Siberian larch seedlings. More intensive nematode reproduction was recorded in P. sibirica, with seedlings dying later than other plants. The preliminary analysis showed that the death of conifer stands of the studied species from pine wilt disease is possible in the climatic zone of Siberia.