Efficacy of oral administration of 20 mg of triclaben-dazole/kg of body weight was evaluated against 12-week Fascioloides magna infections in 12 sheep, each inoculated orally with 250 viable metacercariae. From 6 sheep treated with triclabendazole, 1 immature F magna was recovered, whereas 116 F magna with a mean length of 19 +/- 6.5 mm were recovered from 6 untreated control sheep. Efficacy of triclabendazole was 99.14%. Signs of toxicosis or illness were not observed in the sheep.

Despite of presence of a wide choice of antihelminthics, in the Republic of Belarus it is still a real problem of development of preparations that provide long-term treatment and preventive maintenance efficiency against helminthosis. At the same time, helminthes and anthelminthics render the immunosuppression action. The solution of this problem can be a combined application of antihelminthics and adjuvants. There were proposed preparations Albepolis and Averpolis. Their application made it possible not only to release an organism of animals from parasites, but also to correct the state of immune system. The obtained research data confirm the available data about the immunosuppression action of parasites on an organism of animals. There was also is noted the immunosuppression action of Albendazol and Aversektin C in therapeutic doses. Albendazol possess a wide spectrum of action against trematodes, nematodes, cestodes. It interrupts the metabolism, oppresses fumarate reductase activity and adenosine triphosphate synthesis of a parasite. It proved to be low-toxic for homoiothermal animals. Albendazol rendered positove influence on growth, development and increase of cattle productivity.

In the conditions of the Republic of Belarus there were determined the parameters of acute and subacute toxicological characteristics of the developed in the Vitebsk State Academy of Veterinary Medicine anthelmintic preparations of durable action Febolvetum-О for control of sheep strongylatosis and Febolvetum for control of strongylatosis of cattle young stock. Data on determination of toxicological parameters of the prolonged action bolus were presented. Research results showed that the preparations did not render negative influence on laboratory animals (white mice). According to the parameters of acute oral toxicity the Febolvetum was qualify as the third hazard class. In accordance with the results of study of subacute toxicity parameters of the preparations, it was concluded, that in the conditions of free feeding of Febolvetum boluse in combination with forages in course of 30 days in doses of 200 mg/kg; 150 mg/kg; 100 mg/kg of body weight in animals there were found no signs of intoxication; there were not stated any is not fixed deviations in physiological state; and were stated no mice death.

In the conditions of the Republic of Belarus there was studied the application of sodium chloride obtained by electrolysis method on Akvamed installation in a complex of activities for the preventive measures of animal helminthoses. Electrochemical activation of aqueous solution of sodium chloride proved to be a progressive and rational technology which made it possible to substantially reduce the material costs and power consumption for the development of highly efficient and ecologically safe disinvasion solution. Application of sodium chloride solution with the minimal content of available chlorine of 3,0 g/l provided the death of 94-95% of Taeniidae eggs in course of 30 minutes after applicated of the preparation on the treated surface. The proposed method can be recommended as the most efficient and economically effective for the disinvasion of external environment.

In the conditions of the Republic of Belarus there was analyzed fauna of parasites of gastro-intestinal tract and natural resistance of horses in the conditions of Polesye State Radiation Ecological Reserve. There were worked the most efficient antihelminthic compounds. Analysis of helminthological state showed that extensiveness helminthic and gastrophilosis invasion of horses was at a high level. In this regard the nematodosis and gastrophilosis (Gastrophilus intestinalis) invasions prevailed. In mature and growing horses there was marked the dominance of nematode worms of Strongylidae / Trichonematidae families (78,9-83,8%) and Gasterophilidae (95,8%). Next, at growing horses there were stated nematodes Strongyloides westeri and cestoid worms of Anoplocephalidae family, at mature horses – of Gasterophilidae, Parascaris equorum and Oxyuris equi families. The following antihelminthic compounds ans preparations showed the best efficiency: Univerm; Avermektin paste 1%; Fenbendazoli, Rivertin 1%.

Development of scientifically based activities for rehabilitation of waterfowl (ducks) against helminthoses on the territory of the Republic of Belarus was realized. In course of the study there were analyzed fauna of helminthes and revelation of the main ways of their circulation in environment conditions; expansion and species composition of mollusks of Belarusian Poozerye; determination of species composition of metacercaria revealed in mollusks. In course of determination of intermediate and additional hosts of helminth infestation of ducks it was noted that the main carriers of larval stages of helminthes in ducks were the following species of frash-water mollusks: Vivaparus contectus; Vivaparus vivaparus; Galba palustris; Radix ovata; Radix auricularia; Sphaerium subsolidum; Bithynia tentaculata; Planorbis carinatus; Planorbis planorbis; Coretus corneus. In the studied samples there were revealed metacercaria of Echinostoma revolutum; Hypoderaeum conoideum; Cataropis verrucosa; Echinostoma dietsi. Assumption that some representatives of molluscum (Viviparus contectus; Viviparus viviparus; Planorbis planorbis) were the transport hosts for echinostomiasis was not proved.

In course of realized in the conditions of the Republic of Belarus research there were studied the relations of the most widely spread helminthes and protozoan which infest in gastrointestinal tract of dogs with the normal microflora of small intestine and large intestine. Research results showed that in the conditions of single-agent infestation and associative parasitic disease of dogs caused by Toxocara canis, Toxascaris leonine, Dipylidium caninum, Uncinaria stenocephala, Taenia sp., Isospora ochioensis, Isospora canis and Eimeria canis in small and large intestine of sick animals there was seldom stated the changes of quality and quantity composition of microflora. In the conditions of mixed agents infestation the microflora composition changed more intensively