DISEASES OF THE HEAET. 235 



may give marked relief, or, late in the disease, smart blisters may be 

 applied to the sides of the chest with benefit. If the disease becomes 

 chronic, iodide of iron and gentian to support the strength will be 

 indicated, but the iodide of potassa, in 1 or 2 dram doses, two or three 

 times a day, must not be abandoned so long as there is an evidence of 

 effusion or plastic exudate accumulating in the pericardial sac. 

 "^Aliere the effusion is great and threatens the life of the patient, 

 tapping by an expert veterinarian may save the animal. 



VALVULAR DISEASE OF THE HEART. 



Acute valvular disease can not be distinguished from endocarditis, 

 and chronic valvular affections are generally the result of endocar- 

 dial inflammation. The valves of the left side are the most subject — 

 the bicuspid or mitral and the aortic or semilunar. The derange- 

 ment may consist of mere inflammation and swelling, or the edges of 

 the valves msij become covered by the organization of the exudation, 

 thus narrowing the passage. Valvular obstruction and adhesions 

 may occur or the tendinous cords may be lengthened or shortened, 

 thus obstructing the orifices and permitting the regurgitation of 

 blood. In protected cases the fibrous tissue of the valves may be 

 transformed into fibro-cartilage or bone, or there may be deposits of 

 salts of lime beneath the serous membrane, which may terminate in 

 ulceration, ruj^ture, or fissures. Sometimes the valves become cov- 

 ered by fibrinous, fleshy, or hard vegetations, or excrescences. In 

 cases of considerable dilatation of the heart there may be atrophy and 

 shrinking of the valves. 



Symjjtoms. — Valvular disease may be indicated by a venous pulse, 

 jerking pulse, intermittent pulse, irregular pulse; palpitation; con- 

 stant abnormal fullness of the jugular veins; difficulty of breathing 

 when the animal becomes excited or is urged out of a walk or into a 

 fast trot ; attacks of vertigo ; congestion of the brain ; dropsical swell- 

 ing of the limbs. A blowing, cooing, or bubbling murmur may some- 

 times be heard by placing the ear over the heart on the left side of the 

 chest. 



Hypertrophy, or dilatation, or both, usually follow valvular disease. 



Treatment. — "\Mien the pulse is irregular or irritable, tonics, such 

 as preparations of iron, gentian, and ginger, may be given. When 

 the action of the heart is jerking or violent, 20 to 30 drop doses of 

 tincture of digitalis or of veratrum viride may be given until these 

 symptoms abate. As the disease nearly always is the result of endo- 

 carditis, the iodide of potassa and general tonics, sometimes stimu- 

 lants, when general debility supervenes, may be of temporary benefit. 

 Very few animals recover or remain useful for any length of time 

 after once marked organic changes have taken place in the valvular 

 structure of the heart. 



