THE EFFECTS OF THYROIDECTOMY, CASTRATION, ANTERIOR LOBE ADMINISTRATION AND PREGNANCY UPON EXPERIMENTAL DIABETES INSIPIDUS IN THE CAT

Abstract

The observation previously made, that thyroidectomy may somewhat reduce but does not abolish the polyuria produced by lesions of the supraoptico-hypo-physeal system in cats, was confirmed in 4 other cats. Feeding desiccated thyroid to such animals elevated the water exchange to equal or exceeding the level existing before thyroidectomy. Castration performed on 4 cats with diabetes insipidus failed to diminish the polyuria, and in 1 of these the water exchange increased after ovariectomy. Administration of a crude ant. lobe preparation, while ineffective in producing polyuria in normal cats, may increase the water exchange in cats with a tendency to diabetes insipidus. It is not invariably effective, however, and cats already displaying marked polyuria may not respond to such treatment. Cats operated in the early stages of pregnancy may develop marked polyuria which persists, with some indication of diminution immediately before parturition. In the few cases available at present, parturition has been apparently abnormal, has not been completed and has ended fatally for the mother cat. This has prevented observation as to the course of the polyuria after parturition.