The aim of the present study was to investigate of the therapeutic efficacy of the two- components antimicrobial drug. The drug contains two antimicrobial components that act synergistically. Acute intestinal infection of calves was treated. The drug was given with food. The dose and method of administration were determined by the manufacturer. Before use, the sensitivity of pathogenic microorganisms to the active components of the drug was determined. During the experiment, constant monitoring of the clinical condition and physiological parameters of the organism of experimental animals was performed. Evaluation of hematological and biochemical parameters of the body was performed according to recognized methods. Therapeutic efficacy was compared with data obtained using the reference drug. The obtained data were processed statistically. Based on the obtained data, conclusions were made about the effectiveness of treatment and the effect of the drug on the body of young cattle. According to the assessment of the clinical condition of the animals and the results of laboratory studies, it was found that the tolerability of the study drug for the treatment of intestinal infections in young animals was good. During the experimental period and two weeks after the use of drugs, no side effects were detected and no changes in the behavior of calves were observed. The therapeutic efficacy of the study drug was 100 %, and the recovery period was 5 days. Comparative analysis of hematological parameters of calves showed a significant decrease in the percentage of rod-shaped neutrophils in the leukogram of sick animals after antibiotic therapy. Normalization of the leukogram indicated the cessation of inflammatory processes and improvement of the physiological condition of animals. Analysis of the influence of drugs on biochemical indices in experimental calves showed no changes during the observation period. Negative impact on liver indicators under administration weren't found. Laboratory studies have not revealed nephrototoxic effects of antimicrobial drugs. Confirmed the safety and therapeutic efficacy of the two antimicrobial components drug.

The article presents the results of clinical trials of tolerance of the drug, containing the flavonoid quercetin, on clinically healthy dogs. Quercetin is a biologically active substance that can have antioxidant, membrane, gastro-, nephro-, hepato-, cardioprotective, antiplatelet, anti-inflammatory effects. The flavonoid quercetin belongs to the aglycones of many plant flavonoid glycosides of higher plants. Some pharmacological effects of quercetin have been discovered recently, but the prospects of its use in veterinary medicine are being intensively studied, given its promising positive effects on the animals` body. The bioavailability of quercetin is highest in combination with pectin and insoluble oligosaccharides, which is associated with changes in the quantitative and qualitative composition of the mammals’ intestinal micro flora. A prerequisite for the development and testing of new veterinary medicinal products in accordance with the requirements of the international community for the registration of medicinal products is the conduct of clinical trials in compliance with the requirements of "Good Clinical Practice" (GCP). The introduction of biologically active drugs in the practice of veterinary medicine requires careful researches on target species of animals. Therefore, to assess the tolerability, safety and efficiency of the drug containing quercetin, a comprehensive clinical trial was performed on small pets (dogs). The study was conducted in veterinary clinics on healthy dogs of all ages, genders and breeds. The drug was used at a dose of 4 mg/kg body weight orally with food for 30 days. Blood sampling in test animals was performed before drug use and on days 30 and 60 of the experiment. The effect of the drug on the body was evaluated by clinical indicators, hematological and biochemical parameters of dogs' blood. Stabilized EDTA blood was used for morphological studies and blood serum for biochemical studies. According to the evaluation of the animals’ clinical condition and the obtained data of laboratory studies, it was found that the tolerance of the studied drug, administered orally to healthy dogs, was good. According to the results of comparison of clinical, hematological and biochemical parameters on the 30th and 60th day of the study with the initial data obtained before the use of the study drug, no negative changes were detected. Hematological studies indicated the activation of hematopoietic processes, normalization of leukogram parameters on 30th day after the drug application. Changes in the lymphocytes` content in the leukogram and the γ-globulin fraction in the protein-gram indicated a strengthening of dogs` immune protection. The results of biochemical studies of dogs's blood on the 30th day showed a reliable increase, within normal limits, in glucose, creatinine contents, increased catalase and alanine aminotransferase activity and decreased gamma-glutamyltransferase activity and the contents of diene conjugates and malonic dialdehyde. Activation of protein metabolism was established, which was indicated by a reliable increase in the total serum protein content and albumin content in the dogs` proteinogram. On the 60th day of the drug application no significant changes in hematological and biochemical parameters of the blood of dogs were detected. There was a slight decrease in the activity of catalase and SOD and a decrease in the content of malonic dialdehyde in the serum of dogs, compared with the values on the 30th day. This, in turn, showed a decrease in the intensity of the formation of toxic compounds in animals and pronounced antioxidant properties of the drug Hepanephran.