Heartwater. Hog Cholera. 257 



Heartwater. According to Theiler a disease of cattle occurs in 

 several localities of Transvaal, which is known there as Veldt-sickness. 

 The most striking symptom of the disease is the filling of the pericardium 

 Avith a colorless or yellowish fluid (hence the name heartwater). There 

 is also a pronounced indication of acute gastro-enteritis present. The 

 micro-organism is, according to Counsbury, transmitted from the af- 

 fected to the healthy animals, by a tick (Amblyomma hebraeum) ; 

 sheep and goats are also very susceptible. 



The same disease occurs also among sheep and goats, and may 

 readily be produced by the subcutaneous or intravenous injection of 

 blood, but not of the pericardial fluid. The transmission may be made 

 from sheep to cattle, and vice versa. The symptoms develop 5-15 days 

 after the injection, and consist of high fever, dullness, exceptionally 

 also in nervous symptoms, such as continuous moving of the tongue 

 and the jaAvs, turning in a circle, later a stifi'ness of the neck (hence 

 the name "brainwater"). The autopsy reveals a great quantity of 

 fluid in the pericardium and pleural cavity, also petechiae on the peri- 

 cardium, edema of the lungs and moderate acute swelling of the spleen. 



The disease, which has lieen known in South Africa for about 

 40 years occurs only in certain localities, principally during the summer 

 time, and in pastures located upon high lands. The Kaffir goat and 

 the native fat-tailed sheep are not susceptible, while the Persian sheep 

 are only slightly susceptible to the disease. 



Hyperimmunized cattle, sheep and goats produce an effective 

 serum for their respective species, a practical immunization however 

 has not yet been established. 



The supposition of Edington that the disease is identical with 

 *' horse-sickness " is considered by Theiler as incorrect, as horse-sickness 

 can be transmitted artificially only to horses (see page 286). 



According to Edington 's view the disease is identical with the African horse- 

 sickness (see that disease). Spreiill on the other hand contends that the diseases 

 of cattle occurring in South Africa under the names Laniziekte, Gall-sickness, Veldt- 

 sickness, Blood-lung and Inapunga are identical with Heartwater, and he considers 

 their causative agent to be a motile bipolar bacillus. Clinically he distinguishes an 

 edematous form, with swellings on the neck and hea<l, a thoracic form with con- 

 gestion and hepati2ation of the lungs, and a paralytic form which is associated 

 with a stiffness of the gait. 



Literature. Theiler, The Vet. J., 1904, IX, 300; The transv. agrie. J., 1904, 

 II, 163; Bull. Pasteur, 1905, III, 617; J. of comp. Path., 1905, XVIII, 155.— Eding- 

 ton, J. of comp. Path., 1904, XVII, 141.— Spreull, V. J., 1908, 358. 



11. Hog Cholera. Pestis suum. 



{Swine fever, Typhoid fever; Scliweinepesf [German]; Cholera 

 smim, Pesfe du pore [French']; Peste porcina [Italian].) 



Hog cholera is usually an acute, siib-aciite or chronic, more 

 rarely a peracnte, contagions, infections disease of hogs, cansed 

 by a filterable virns. In the conrse of the disease, with the excep- 

 tion of the peracnte cases, inflammatory and necrotic processes 

 develop, prodnced either by the bacillns snipestifer when the 

 lesions occnr in the intestinal canal and in the abdominal lymph 

 glands, or by the bacillns snisepticus when the lesions are mani- 

 fested in the Inngs. 



