1056 Tachycardia. 



S3miptoms. The entire behavior of the animals, especially 

 their distressed expression, reveals great anxiety, the animals 

 tremble, horses and cattle perspire. In the heart region thrills 

 are seen which are synchronous with the heart beat and Avhich 

 are sometimes transmitted to the entire trunk and to the 

 vertebral column. The heart beat is stronger, as a rule much 

 accelerated and arhythmical in so far as a number of rapid 

 heart beats alternate with several which are less rapid, or 

 as brief intermissions occur. The heart sounds are very strong 

 and are sometimes audible from a distance of several steps. 

 At the same time the pulse is usually feeble. These sjanptoms 

 permit the assumption that a heart weakness Avas present in 

 the cases in question, and this assumption is strengthened by 

 other signs mentioned by several authors, such as intermittent 

 pulse, systolic murmurs, greater fullness and pulsation of the 

 jugular vein. 



Diagnosis. The assumption of nervous palpitation pre- 

 supposes the absence of any organic disease of heart or blood 

 vessels which could produce similar disturbances in the heart 

 function. Severe acute general diseases must also be eliminated. 



Course. Palpitation always lasts only a short time, a few 

 hours, or at most one-half to one day, after which the attack 

 disappears either rapidly or quite gradually. In horses that 

 are otherwise healthy, further attacks usually occur only if 

 the external influences are repeated, but anemic and otherwise 

 predisposed animals may have attacks in rapid succession. 

 The tachycardia which is due to paralysis of the vagus is 

 usually permanent, but as a rule it is followed in a few days 

 by a foreign-body-pneumonia (vagus pneumonia). 



Treatment. An attack of true tachycardia usually passes 

 over without any treatment after complete rest is secured and 

 the diet regulated. In nervous excitement the following drugs 

 may be administered: morphine (for horses 0.30-0.50 gm., for 

 dogs 0.02-0.05 gm. subcutaneously), chloral hydrate (20-40.0 

 or 1-2.0 g-m. dissolved in lukewarm water, per os or per anum), 

 possibly potassium bromide (10-15.0 gm. or 1-2.0 gm. in the 

 drinking water). Other narcotics may be given successfully. 

 Cardiotonic remedies should be administered if cardiac weak- 

 ness is present. 



Literature. Biedo, Ann., 1897. 31. — Krooii, Holl. Z., 1899. 388. — Martins, 

 Tachy-Kardie, 1895; Ergeln. d. Path., 1894. I. 2. Abt., 59 (Lit. on tachycardia 

 in general). — Nordheim, Z. f. Vk., 1890. 275. — Pr. Mil. VI., 1900. 147. — 

 Sehniitt, B. t. W., 1897. 590. 



2. Slow Heart Action. Bradycardia. 



Slowing of the heart action depends upon a functional 

 disturbance in the heart muscle without any demonstrable 

 organic changes. 



