Syiiiptums. Course. Diagnosis. (J53 



tempts to free itself and falls over backwards. After an attack 

 which at the most lasts for an hour or two there is a period of 

 depression and great dullness, which gradually passes off after 

 some hours. 



The acute attacks which are observed in cases in which the 

 hydrocephalus is preceded by meningitis or encephalitis are of 

 much greater importance. These attacks cause an exacerba- 

 tion of the inflammatory processes (see pages 600 and 640), and 

 not rarely cause death, although the condition of the animal is 

 not dangerous. 



After the passing of these acute attacks, which sometimes 

 last for several days, there is almost always a turn for the 

 worse. 



The symptoms above described are characteristic in a general way of the 

 disease known as staggers which is most frequently caused by dropsy of the ven- 

 tricles. But staggers should not be identified with chronic hydrocephalus because 

 this has a far wider significance than chronic dropsy of the ventricles. Similar 

 symptoms are observed in all diseases of the brain which are of a chronic nature 

 and which are associated with a rise in the intracranial pressure, or destruction 

 of the brain substance (neoplasms, parasites in the cranial cavity, exostoses on the 

 inner surface of the cranial bones, chronic inflammation of the brain, etc.). 



Course. Chronic dropsy of the ventricles of the brain runs 

 a slow course and apart from the occasional exacerbations there 

 is no fever from first to last. Owing to the accumulations of 

 the fluid and to the consequent rise of intracranial pressure 

 certain s^miptoms make their appearance which at the outset 

 are scarcely recognizable and which scarcely affect the animal's 

 condition, but which in the course of time become so severe that 

 the animal can be used for rough w^ork only. In some cases the 

 slow evolution of the disease is interrupted by marked im- 

 provements and by relapses from time to time. In addition to 

 the factors mentioned above, the season exerts an influence on 

 the disease, there being an improvement in the winter, the ani- 

 mal becomijig worse in the summer. It is very exceptional for 

 the disease to progress so far that the animal is absolutely 

 without intelligence, takes scarcely any food, and as a result 

 falls off greatly in condition. If the animal does not die during 

 an acute exacerbation or from some other concurrent acute dis- 

 ease it is usually slaughtered before it becomes absolutely 

 senseless on account of its very limited use. 



Diagnosis. In the advanced stages of the disease the symp- 

 toms due to distur])ance of the cereliral functions are so obvious 

 that they can be recognized in an instant. In the early stages 

 their recognition is associated with great difficulty and a sys- 

 tematic examination of the horse is essential. Skill is very nec- 

 essary in this, because a practiced eye at once suspects loss of 

 intelligence from the general facial expression and particularly 

 from the appearance of the eye, even when there are no abnor- 

 malities of movement, sensitiveness or reflexes. The age, 



