Scientific Proceedings (54). 



had evidently been too feeble or incoordinated for the delivery. 

 Two dogs showed no signs of tetany at any time, one of the dogs 

 giving birth to the young on the 6th day, and the other on the 9th 

 day following the parathyroidectomy. Three weeks later the 

 dogs were killed and a search made for accessory parathyroids; 

 none were found. 



The development of acute and fatal tetany within 24 hours 

 after parathyroidectomy is very exceptional in male and non- 

 pregnant female dogs. It does occur, however, especially after 

 hemorrhage or prolonged anaesthesia. It would therefore seem 

 that late pregnancy in dogs accelerates and intensifies the para- 

 thyroid tetany in the majority of cases. This may, however, 

 be only an addition effect (latent eclampsia + parathyroid tetany). 



2. Cats. — Ten out of the eleven pregnant cats developed fatal 

 tetany. The slight difference between pregnant and non-pregnant 

 cats is shown by the following comparison : 



Parathyroid tetany ; average figures for : 

 20 males and non-pregnant females. 10 females in late pregnancy. 



f Maximum 72 hours 48 hours 



First tetany symptoms-^ Minimum 5 hours 24 hours 



^ Average 28 hours 30 hours 



f Maximum 168 hours 175 hours 



Deaths Minimum 24 hours 75 hours 



^Average 78 hours 120 hours 



It is obvious that advanced pregnancy in cats does not accelerate 

 or intensify the symptoms of parathyroid tetany. On the contrary 

 the pregnant cats live a little longer and the excitation symptoms 

 are less severe than in the case of the non-pregnant controls. But 

 the depression seemed greater in the pregnant animals. If the 

 fetal parathyroids are in any way capable of functioning for the 

 mother, this action is so slight that it cannot be demonstrated 

 on the present short series of experimental animals. 



It is premature to speculate on the cause of the above difference 

 in the relation of pregnancy to parathyroids in cats and dogs 

 before more data are at hand on other species. 



