Evaluation of embryotoxicity or teratogenicity of complex antibacterial preparation for treatment of mastitis in lactating cows

Abstract

The aim of the study was to assess the effect of a new complex antibacterial drug for the treatment of mastitis in lactating cows on white laboratory rats during embryonic and early postnatal development. It was found that the drug in the studied dosage of 250 mg/kg when used from 1 to 7 and from 7 to 19 days of gestation did not cause undesirable reactions in white rats, and also did not affect the formation and development of the fetuses. The increase in body weight of pregnant females was uniform in all groups. Moreover, the number of the fetuses, corpora lutea, the weight of the fetuses and placentas, the size of the fetuses did not have statistically significant differences in the experimental groups relatively to the control. The analysis of the intrauterine mortality rates also did not reveal statistically significant differences in the groups. A macroscopic examination of the fetuses revealed no developmental anomalies in any of the groups. During pathomorphological study it was found that there were no changes in the structure of internal organs, fetal development was consistent with the gestational age. The number of live and stillborn cubs per female did not significantly differ in all groups. In all infant rats, no abnormalities or deformities were observed after birth. The increase in body weight of the offspring in the experimental groups was uniform. Statistically significant differences in physiological development, both in the experimental and in the control groups, were not observed. Thus, the application of the studied drug to the laboratory rats during critical periods of pregnancy did not cause negative effects in the offspring during embryonic and early postnatal periods. Based on this, we can conclude that this drug in the studied dosage does not have embryotoxic and teratogenic effects.