Etiology. Anatomical Changes. Symptoms. 629 



is mal-nutritioii of the vessel walls, and also to acute infectious 

 diseases, such as anthrax, purpura, hemorrhagic septicemia, etc. 

 Hemorrhage of the brain may also occur in cases of anemia, 

 leucemia, hemophilia, chronic hepatitis, and nephritis. In the 

 horse hemorrhage in exceptional cases is due to rupture of an 

 aneurism of some artery of the brain, the aneurism having been 

 caused by the larva} of sclerostomes (Kitt). In many cases it is 

 due to heart disease (Hering, Scoffie), but neoplasms, such as 

 gliomata and gliosarcomata are rarely concerned, owing to their 

 very infrequent occurrence. So far no one has demonstrated 

 atheromatous arteritis of the vessels of the brain in cases of 

 hemorrhage in the lower animals, and in any case that condition 

 must be far more rare in animals than in man (Dexler). The 

 outbreaks of cerebral hemorrhages observed by Vath were, in 

 view of the course of the disease, in all probability due to an in- 

 flammatory process of some kind. 



Diseases of the vessel walls may per se lead to hemorrhage 

 or there may be other factors involved. In this connection an 

 increase in blood pressure plays an important part (during 

 work, excitement, etc.). 



Anatomical Changes. The hemorrhages are, as a rule, 

 small and punctiform, but they may be larger. The majority 

 are to be found in the cortex and the large ganglia. On the cut 

 surface they appear as purple-red points which can neither be 

 scraped off w^itli a knife nor washed away with a stream of 

 water. 



Hemorrhages between the membranes, or between the dura 

 and the cranium (intra- or extrameningeal hemorrhage), occur 

 more frequently and especially in cattle. In such cases the hem- 

 orrhages tend to be more extensive (see fig. 86). 



Symptoms. The smaller the hemorrhages and the more 

 localized they are the less is the intracranial pressure increased. 

 Under such circumstances both general and local symptoms are 

 proportionately slight. The capillary hemorrhages that occur 

 in acute infectious and other disease usually pass unnoticed. In 

 cases where the hemorrhages are more extensive the symptoms 

 resemble those seen in cases of contusion of the brain. The ani- 

 mal is giddy, stumbles and trembles, may make involuntary 

 movements, and then collapse and fall to the ground in a state 

 of coma. Death may supervene with convulsions, or there may 

 be recovery sooner or later. In such cases there may be symp- 

 toms of a general or local nature which may be permanent or 

 temporary, and these may cause death in the end. If the hemor- 

 rhage is not very severe there may be no complete loss of con- 

 sciousness, the animal only showing giddiness and unsteadiness 

 of gait, and in addition certain local symptoms. Hemorrliages 

 of the medulla which are somewhat more extensive generally 



