Etiology. 919 



time to time. The feeding of such oats soon produces polyuria 

 which may pass into a pathological condition similar to diabetes 

 insipidus if the spoiled oats is continued for a long time. In 

 former times when oats was often transported on ships on 

 which it was impossible to turn it over at frequent intervals 

 the disease was observed more frequently, and sometimes in 

 an enzootic form. Today it occurs far less often because the 

 oats is usually shipped in bags (Dieckerhoff). Other mouldy 

 kinds of feed may likewise produce a similar effect ; for instance 

 mouldy hay, peas, vetches, etc., but these can not nearly as often 

 be brought into connection with the appearance of the disease, 

 perhaps because the coarse feed, even in large quantities, can 

 be ventilated more easily than is possible with oats. More- 

 over it is not impossible that peculiarly toxic substances are 

 formed in mouldy oats. 



Certain plants are credited with the ability to eanse diabetes. As such are 

 considered the different species of Adonis and Anemone, and above all the Cynanchum 

 s. Asclepias vincetoxicum, the latter especially since Veith succeeded in causing 

 polyuria in sheep Ijy feeding it to them. According to Eoll fro2en fodder and sloi) 

 are also at times the cause of diabetes. 



Aside from transitory polyuria true diabetes is occasionally 

 observed as a complication of affections of the central nervous 

 system, but such cases are hardly known to have occurred in 

 animals. 



Other etiological factors are : The continued administration 

 of diuretics, cold, traumatic accidents to the liver or to the 

 vertebral column; some authors (Cagny, Cagnat) assume an 

 infection as the cause of cases which occur in greater numbers. 



Horses which are used for heavy work and, according to 

 Moiroud, especially stallions appear to be most disposed to 

 diabetes insipidus, while age and race have no influence. The 

 disease usually occurs more frequently in summer than in 

 colder seasons. 



The nature of diabetes insipidus is unknown. This much is cer- 

 tain that a transitory polyuria can be produced artificially by injuring 

 a certain spot in the fourth ventricle near the Calamus scriptorius 

 (01. Bernard). Later it M-as ascertained that injuries to other portions 

 of the brain, especially the vermiform process of the cerebellum, as 

 well as the division of the lumbar cord, or of the splanchnic nerve 

 also produces similar results. These experiments permit the conclusion 

 that diabetes insipidus perhaps also originates from nervous causes, 

 and according to this view the effect of mouldy fodder would have to 

 he explained thus, that substances developed in it produce polyuria 

 by the intermediation of the nervous system. It may be assumed 

 that through disease of tlie vasomotor nerves in the kidneys a constant 

 arterial hyperemia is maintained in consequence of which the amount 

 of urine or its content of water is increased. Against this view stands 

 the demonstration recentlj^ afforded by E. Meyer and F. Miiller that 

 diabetes insipidus in man represents in fact only a secretory anomaly 

 of the kidneys through which the organism requires very great amounts 



