68 



Scientific Proceedings (47). 



9. The predisposition to more sudden and severe electrical 

 irritability, when further parathyroid loss is suffered, by animals 

 previously subjected to parathyroid injury. 



10. The influence of gestation on the galvanic response of 

 parathyropriva animals. 



Technique. — Ether anesthesia. 



Three procedures or a combination of the first two were fol- 

 lowed. 



1. The parathyroid gland or glands were exposed, lifted on the 

 point of a needle and excised or crushed. 



2. A thyro para thyroidectomy of one side was done. 



3. A complete thyroparathyroidectomy was done on both 

 sides and thyroid extract given to the dog. 



For the galvanic tests the peroneal nerve-muscle group was 

 used. The negative electrode was placed on the upper abdomen, 

 the positive over the peroneal nerve as it passes around the head 

 of the fibula. The instrument employed supplied a galvanic cur- 

 rent from dry cells and was provided with a rheostat, polarity 

 switch and balanced milliampere-meter measuring from .2 to 10 

 milliamperes. 



Findings. — 



1. In normal adult dogs K.C. is usually less than 2 m.a. and 

 may vary between 1 m.a. and 3 m.a. A.C. is usual at from 3 to 5 

 m.a. It is seldon less than three and often greater than 5 m.a. 

 A.O. is rarely obtained at less than 5 m.a. K.O. is never below 

 5 m.a. 



2. Young puppies are less susceptible to galvanic stimulation 

 than grown dogs. K.C. and A.C. alone are obtained at less than 

 5 m.a. Frequently K.C. alone is obtained and not often below 

 3 m.a. 



3. Comparison of the findings on normal and parathyropriva 

 dogs with over 300 observations on normal children and children 

 having tetany shows that galvanic response is very similar in the 

 two classes. 



4. Of 4 dogs with one parathyroid gland removed, none de- 

 veloped frank 1 tetany. Two showed mild anodal hyperirritability 



1 By frank tetany is meant the development of tremors, muscular or laryngeal 

 spasms, convulsions or paralyses. 



