412 DISEASES OF CATTLE. 



tion, or madness, which is indicated by increasing restles.sness, loud 

 roaring at times with a peculiar change in the sound of the voice, 

 violent butting with the horns and pawing the ground with the 

 feet, with an insane tendency to attack other animals, althcTiigh the 

 desire to bite is not so marked in cattle as in the canine race. A con- 

 stant symptom is the increased secretion of saliva with a consequent 

 frothing at the mouth, or the secretion may hang from the lips in long 

 strings. Constipation is marked, and there is manifested a continiuil, 

 although unsuccessful, desire to defecate. Spasms of the muscles in 

 different parts of the body are also seen at intervals. About the 

 fourth day the animal usually becomes quieter and the walk is stiff, 

 unsteady, and swaying, showing that the final paralysis is coming 

 on. This is called the paralytic stage. The loss of flesh is extremely 

 rapid, and even during the short course of the disease the animal 

 becomes exceedingly emaciated. The temperature is never elevated, 

 it usually remaining about normal or even subnormal. Finally, 

 there is complete paralysis of the hind quarters, the animal being 

 unable to rise and but for irregular convulsive movements lies in a 

 comatose condition and dies usually fiom the fourth to the sixth day 

 after the appearance of the first symi)tom. 



Anatomy. — If animals which have succumbed to rabies be exam- 

 ined post-mortem, vei*y slight evidence of disease will be foun<l in 

 any of the organs, and, indeed, the absence of any specific lesions may 

 be considered as characteristic. The blood is dark and imperfectly 

 coagulated. The throat is frequently reddened, and there may be 

 small spots of extravasated blood in the intestines. The stomachs 

 are usually empty. In the spleen there may be hemorrhagic enlarge- 

 ments (infarcts). The cadavers rapidly undergo decomposition. 



Differential diagnosis. — It is not an easy matter to decide definitely 

 that a given animal has rabies, since the symptoms given above be- 

 long in part to a variety of other diseases, among which may be men- 

 tioned the excitement seen in young animals following close confine- 

 ment, certain vegetable and mineral poisons, acute enteritis, and 

 alterations of the central nervous system in cattle, the most common 

 of which is tuberculosis of the brain and its covering membranes. 

 However, the post-mortem lesions should assist in making a correct 

 diagnosis. Tetanus may readily be differentiated from rabies by the 

 persistence of muscular ciamps. especially of the face and abdomen, 

 which cause these muscles to become set and as hard as wood. In 

 tetanus there is also an absence of a depraved appetite or of a willfid 

 propensity to hurt other animals or to damage the sun'oundings. 

 The cow remains quiet and the general muscular contraction gives 

 the animal a rigid appearance. There is an absence of paralysis 

 which marks the advanced stage of rabies. The dumb form of rabies 

 in dogs is characterized by the paralysis and pendency of the lower 



