204 EUKEAU OF ANIMAL INDUSTRY. 



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 h^ 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- 

 quentl}^ and give rise to a variety of symptoms, imperfect control of 

 voluntary movement, local paraly.sis, epilepsy, etc. Among- the more 

 common tumors are the following: 



Osseous tumors^ growing from the walls of the cranium, arc not very 

 uncommon. 



Dentigerous cysts^ containing a formation identical to that of a tooth, 

 growing from the temporal bone, sometimes are found l3"ing loose 

 within the cranium. 



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

 met with on postmortem 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 string-halt. 



Fibrous tumors may develop within or from the meningeal structures 

 of the brain. 



Gliomatous tumor is a variety of sarcoma very rarely found in the 

 structure of the cerebellum. 



Treatment for tumors of the brain is impossible. 



SPASMS, OR CRAMPS. 



Causes. — Spasm is a marked symptom in many diseases of the brain 

 and of the spinal cord. Spasms may result from irritation of the 

 motor nerves as conductors, or may result from irritation of an}^ part 

 of the sympathetic nervous system, and they usually indicate an excess- 

 ive action of the reflex motor centers. Spasms may be induced by 

 various medicinal agents given in poisonous doses, or by effete mate- 

 rials in the circulation, such as nux vomica or its alkaloid strychnia, 

 lead preparations, or an excess of the urea products in the circulation, 

 etc. Spasms may be divided into two classes: Tonic spasm .^ when the 

 cramp is continuous or results in persistent rigidity, as in tetanus; 

 clonic spasm^ when the cramping is of short duration, or is alternated 

 with relaxations. Spasms may affect involuntary as well as the vol- 

 untary muscles, the muscles of the glottis, intestines, and even the 

 heart. They are always sudden in their development. 



