DISEASES OF THE HOKSE. 233 



drinking water every four hours for tlie first five or six da3^s, and then 

 be superseded by the nitrate of potassa, in half-ounce doses, for the 

 following week, or until the urinary secretion becomes abnormally 

 profuse. Where the disease is associated with rheumatism, 2-dram 

 doses of salic3date of soda may be substituted for the chlorate of 

 potassa. To guard against chronic iuduration of the valves, the iodide 

 of potassa, in 1 to 2 dram doses, should be given early in the disease, 

 and may be repeated two or three times a da}^ for several weeks. 

 When chronic efi'ects remain after the acute stage has passed this drug 

 becomes indispensable. 



When dropsy of the limbs develops, it is due to weakened circulation 

 or functional impairment of the kidneys. When there is much weak- 

 ness in the action of the heart, or general debility is marked, the iodide 

 of iron, in 1-dram doses, combined with hydrastis, 3 drams, may be 

 given three times a day. Arsenic, in 5-grain doses twice a da}^, will 

 give excellent results in some cases of weak heart associated with diffi- 

 cult breathing. In all cases absolute rest and warm stabling, with 

 comfortable clothing, become necessar}^, and freedom from work 

 should be allowed for along time after all symptoms have disappeared. 



. PERICARDITIS, OR INFLAMMATION OF THE SAC INCLOSING THE HEART. 



Causes. —Pericarditis may be induced by cold and damp stabling, 

 exposure and fatigue, from wounds caused by broken ribs, etc. Gen- 

 erally, however, it is associated with an attack of influenza, rheuma- 

 tism, plcuritis, etc. 



Si/m^toms. — Usuall}^ the disease manifests itself abruptly by a brief 

 stage of chills coincident with pain in moving, a short painful cough, 

 rapid and short breathing, and high temperature, with a rapid and 

 hard pulse. In the early stages of the disease the pulse is regular in 

 beat; later, when there is much exudation present in the pericardial sac, 

 the heart-beat becomes muffled, and may be of a double or rebounding 

 character. By placing the ear against the left side of the chest behind 

 the elbow a rasping sound may be heard, corresponding to the fre- 

 quency of the hea,rt-beat. This is known as a friction sound. Between 

 the second and fourth daj^s this sound may disappear, due to a disten- 

 sion of the pericardium by an exudate or serous eflfusion. As soon as 

 this effusion partly fills the pericardium, percussion will reveal an 

 abnormally increased area of dullness over the region of the heart, the 

 heart-beats become less perceptible than in health, and in some cases a 

 splashing or flapping sound may become audible. 



If the effusion becomes absorbed, the friction sound usually recurs 

 for a short time; this friction mQ.y often be felt by appljdng the hand 

 to the side of the chest. In a few cases clonic spasms of the muscles 

 of the neck may be present. In acute pericarditis, when the effusion 

 is rapid and excessive, the animal ma^^ die in a few days or recovery 



