Incidence of teratological anomalies in control Charles River C-D strain rats

Evaluating the occurrence of teratological anomalies in a normal population of Charles River C-D strain rats of Sprague-Dawley origin found no pronounced visceral anomalies and the most common skeletal anomalies observed were incomplete ossification of interparietals, and incomplete oSSification of supraoccipitals.

Abstract

In order to evaluate the occurrence of teratological anomalies in a normal population, an experiment was conducted in Charles River C-D strain rats of Sprague-Dawley origin. A total of 2155 rat fetuses was studied; of these, 1430 fetuses were examined for skeletal, and 725 for visceral anomalies. The dams received Purina Laboratory Chow, supplemented with 1% cod liver oil NF XIII, and water ad libitum. On day 20 of gestation, the fetuses were removed from each rat by caesarean section. Some of the fetuses (725) were stored in Bouin's solution for visceral examination, and the others (1430) were cleared and stained with Alizarin Red S for skeletal examination. The most common skeletal anomalies observed were incomplete ossification of interparietals (10.70%), incomplete ossification of supraoccipitals (11.05%), and incomplete ossification of centra-arches (6.08%). No pronounced visceral anomalies were observed except for hydroureter (1.38%).