94 DErARTMENT OF AGRICULTURE. 



only uiuler the action of licat and nitric acid. The constant and path- 

 ognomonic lesion of tliis disease is the enlargement and even disintegra- 

 tion of the spleen, with redness and erosion of the stomacb. The blood 

 is always more or less aifected, anaemic, and the functions, of nutrition 

 disturbed. In its course in the south, it resembles the periodic fevers of 

 man ; is usually sub-acute in form, and varies in intensity at different 

 times. 



The expression I have proposed to designate tliis disease is splenic 

 fever of cattle, from the tact that the disease is readily distinguished, as 

 a rule, by the enlargement of this organ, coupled, no doubt, with other 

 lesions. It is an enzootic disease, allied and corresponding to the 

 endemic periodic fevers of man, for whicli the southern States are re- 

 markable; and it may be deemed prudent to use a more general expres- 

 sion than splenic fever, ^iz., tliat of periodic fever of cattle. Splenic 

 fever is readily prevented, in all cattle north of the Gulf States, by pro- 

 tectuig them, during the summer months, from the pastures and roads 

 on which southern cattle have traveled and fed. The prevention of the 

 disease in Texas would call for a further and more extended inquiry into 

 all the local causes in operation 5 but, generally speaking, the condition 

 of soils and grasses might be altered by thorough cultivation, drainage, 

 deep plowing, &c. In Texas I have found that feeding on corn tends to 

 modify the conditions of cattle, and invigorate their constitutions ; and 

 much may be expected from tbe corn -feeding system rather recently in- 

 troduced on a comprehensive scale. 



No specific means of cure have been discovered for the malady ; and 

 palliative measures consist in allowing animals which suffer from the 

 acute form of the disease, abundant mucilaginous drinks, neutral salts, 

 and occasional diffusible stimulants. Animals have recovered when left 

 to nature, as indeed, also, when they have been profusely bled and purged. 



SYMPTOMS. 



Splenic or periodic fever evidently occurs in two forms, and its course 

 may be subdivided into four stages. 



The first form is an insidious, latent, and usually more fiital one. 

 There are few fevers that do not, at times, attack animals in such a way 

 as to produce so little general disturbance as to prevent their recogni- 

 tion in the living animal. Cases of this description occur in rinderpest. 

 I have alluded to them in an official report on the lung plague, the con- 

 tagious bovine pleuropneumonia of Europe, and have witnessed them 

 in outl)reaks of small-[>ox in sheep; but in enzootic maladies, and espe- 

 cially in tiie various forms of anthrax, it is not unfre(]uently found that 

 animals from districts where such diseases arise indicate, after death, 

 that tlu; liealthiest and strongest have suffered, or are suffering organic 

 changes which a special systemic vigor or constitutional resistance hides 

 80 long as the animal is in life. 



