The Histology of the Thyroid Glands of Dogs Sixteen Weeks of Age

In order to possess an understanding of the diseased thyroid gland, it is highly necessary to have a knowledge of the variations which may occur in the normal gland from early foetal life to senility. Variations may be produced by age, diet, sexual cycle, locality and perhaps breed. Each of these factors present very interesting problems. In the Department of Veterinary Anatomy at Iowa State College we are interested in the variable changes which occur in the normal thyroid gland of clogs from early foetal life to senility. The results of some phases of this investigation are now in the process of publication. It is the purpose of this paper to present the histological picture which was found to occur in the normal thyroid glands of dogs sixteen weeks of age. The thyroid of the clog of sixteen weeks appeared to represent what might be called an adult thyroid as the changes earlier, and as will be published later, would indicate