204 DISEASES OF THE HOKSE. 



through the brain, heat stroke, overwork, excessive nutrition, or long- 

 continued indigestion. Common, heavy-headed draft horses are pre- 

 disposed to this condition. 



The symiotoms are an expression of duUness and stupidity, and 

 from their nature this disease is sometimes known as " dumminess " 

 or " immobility." A horse so afflicted is called a " dummy." Among 

 the symptoms are loss of intelligence, stupid expression, poor mem- 

 ory, etc. The appetite is irregular ; the horse may stop chewing with, 

 a wisp of hay protruding from his lips ; he seems to forget that it is 

 there. Unnatural positions are sometimes assumed, the legs being 

 placed in clumsy and unusual attitudes. Such horses are difficult to 

 drive, as they do not respond readily to the word, to pressure of the 

 bit, or to the whip. Gradually the pulse becomes weaker, respiration 

 becomes faster, and the subject loses weight. Occasionally there are 

 periods of great excitement due to temporary congestion of the brain. 

 At such times the horse becomes quite uncontrollable. A horse so 

 afflicted is said to have " staggers." The outlook for recovery is not 

 good. 



Treatment is merely palliative. Regular work or exercise and nutri- 

 tious food easy of digestion, with plenty of fresh water, are strongly 

 indicated. Intensive feeding should not be practiced. The bowels 

 should be kept open by the use of appropriate diet or by the use of 

 small regular doses of Glauber's salts. 



TUMORS WITHIN THE CRANIUM. 



Tumors within the cranial cavity and the brain occur not infre- 

 quently, and give rise to a variety of svmptoms, imperfect control of 

 voluntary movement, local paralysis, epilepsy, etc. Among the more 

 common tumors are the following : 



Osseous tumors^ growing from the walls of the cranium, are not 

 very uncommon. 



Dentigerous cysts^ containing a formation identical to that of a 

 tooth, growing from the temporal bone, sometimes are found lying 

 loose within the cranium. 



Tumors of the choroid plexus, known as hrain sand, are frequently 

 met with on post-mortem examinations, but seldom give rise to any 

 appreciable symptoms during life. They are found in horses at all 

 ages, and are of slow development. They are found in one or both 

 of the lateral ventricles, enveloped in the folds of the choroid plexus. 



Melanotic tumors have been found in the brain and meninges in 

 the form of small, black nodules in gray horses, and in one instance 

 are believed to have induced the condition known as stringhalt. 



Fibrous tumors may develop within or from the meningeal struc- 

 tures of the brain. 



