viii Preface 



plagues which imperil the lives of adults have been brought 

 under measurable control, but those infections involving the 

 safety of the embryo are constantly gathering force. Yet it 

 must be remembered that the sexual health of those animals 

 desired for reproduction is the first basic need in animal 

 husbandry. Reproductive efficiency in purebred cattle, 

 swine, and horses, so far as can be estimated, has dropped 

 below 60 per cent, of the ideal and continues to descend at a 

 discouraging pace. The condition can be relieved only 

 through conscientious and skillful work by veterinarians 

 and breeders. The problem is difficult and the duration of 

 the task infinite. It calls for the adoption of a permanent 

 policy of guarding sexual health in animals — not of "cur- 

 ing" established lesions. The advancement of reproductive 

 efficiency in the best animals is at present the greatest eco- 

 nomic problem in veterinary medicine. 



In a higher realm the study of genital diseases in domestic 

 animals may be made of incalculable value in the elucidation 

 of the basic principles of genital diseases in man. Aside 

 from the specific venereal diseases of man, the genital infec- 

 tions are probably analogous to, and possibly identical with, 

 the general genital infections of animals. What is true of 

 the intra-uterine infections of the embryo in domestic ani- 

 mals is presumably equally true in principle of the human 

 embryo. The veterinarian has opportunities for the study 

 of the infections of the genital organs and embryos of ani- 

 mals wholly denied to practitioners of human medicine. The 

 veterinarian has freely available in the abattoir the genitalia 

 in health and in disease of thousands and millions of freshly 

 slaughtered cattle, sheep, and swine of all ages and of both 

 sexes. The. females are pregnant and non-pregnant and the 

 embryos are of all ages, diseased and healthy. Clinically the 

 veterinarian can palpate the genital organs of the cow and 

 mare freely per rectum and read the anatomical lesions of 

 ovaries, oviducts and uterus as the blind read braille. The 

 fetus can be manipulated, its movements in response to me- 

 chanical stimulation studied, and its physiologic function of 

 swallowing its amniotic fluid recognized. 



