Abstract: The invention is a unique procedure for chemical sterilization of male animals by injection of a suitable solution into both spermatic cords to cause sterilization with loss of libido and spermatogenesis. Chemical agents which have been found effective include weak acids and weak bases, lactic acid being preferred.Secondly, the invention is a procedure for chemical sterilization of male animals by injecting lactic acid directly into both testis causing both loss of spermatogenesis and libido.Thirdly, the invention is a procedure for chemical sterilization of male animals by injecting lactic acid into both caudel epididymis causing sterilization only.

Abstract: An injectable contraceptive vaccine, a method of preparing said vaccine and the method of preventing conception in mammals by use of said vaccine, is disclosed. A vaccine which stimulates the production of antibodies directed against a hormone essential to the reproductive cycle of a mammal is prepared by coupling such a hormone to a carrier to form a hormone-carrier conjugate. Conception in mammals is prevented by injection of such vaccine during the proper period of the reproductive cycle of said mammal.Specifically described is the vaccine prepared by coupling a hormone, such as estradiol-17 beta, with a protein and its use to sterilize a female of the canine species.

Abstract: An injectable contraceptive antiserum, a process of preparing said antiserum and the method of preventing conception in mammals by the use of said antiserum, is disclosed. An antigen which causes the production of antibodies directed against a hormone essential to the reproductive cycle of mammal is prepared by coupling such a hormone with a carrier to form a hormone-carrier conjugate. A mammal is injected with said conjugate, and the produced antiserum is recovered from blood obtained from said mammal. Conception in mammals is prevented by injection of such recovered antiserum during the proper period of the reproductive cycle of said mammal.Specifically described is the antiserum recovered from the blood of a mammal which has been injected with an antigen prepared by coupling a hormone, such as, estradiol-17 beta with a protein and its use to temporarily sterilize a female of the canine species.