INFECTIOUS DISEASES OF CATTLE. 397 



In 1890 590 dogs, 98 head of cattle, 11 cats, and 9 pigs were found 

 rabid. These figures are easily explained when we take into considera- 

 tion the relation between dogs and cattle. The latter are very much 

 exposed to the bites of the former on pastures. It is also well known 

 that dogs are more or less trained and incited to worry cattle at all 

 times. The latter receive bites most frequently on the hind legs and in 

 the hips and about the lower jaw. These places are most accessible to 

 dogs, owing to the habit of cattle to drive their tormentors away by 

 lowering their head and using their horns. 



The virus after being deposited in the wound by the bite of a rabid 

 animal, remains latent for a time. This period of incubation is quite 

 variable in duration. One veterinarian (Gerlach) collected the statis- 

 tics of 133 cases, and found this period to vary from 14 to 285 days. 

 The majority of cases, however, contract the disease in from one to three 

 months after the bite has been inflicted. 



Symptoms. The disease may be divided into a preliminary stage, a 

 stage of excitation or madness, and a paralytic stage. In all cases the 

 termination is fatal and the-cntire course is from 5 to G days. The pre- 

 liminary stage is indicated by loss of appetite and rumination, great 

 restlessness, anxiety, and manifestation of fear. The second stage is 

 characterized by increasing restlessness, loud roaring at times with 

 changed voice, violent butting with the horns and pawing the ground 

 with the feet. A constant symptom is the increased secretion of saliva 

 which hangs from the mouth in strings, and which may be frothy. Con- 

 stipation is marked, and there is manifested a continual effort to 

 defecate, which is unsuccessful. Spasms of the muscles in different 

 parts of the body are also present at intervals. 



In the final stage symptons of paralysis appear, especially in the 

 posterior limbs, and the walk becomes stiff, unsteady, and swaying. 

 Complete paralysis of the posterior half of the body may appear be- 

 fore death. In this final stage the body is very much emaciated, in 

 spite of the brief duration of the disease. It should also be stated that 

 there in no fever or elevation of temperature during the disease. If 

 cattle which have succumbed to rabies be opened very slight evidence 

 of disease will be found anywhere. The blood is dark and imperfectly 

 coagulated. The throat may be reddened and there may be small spots 

 of extra vasated blood in the intestines. The stomachs arc usually empty. 

 In the spleen there may be hemorrhagie enlargements (infarcts). The 

 cadavers rapidly undergo decomposition. 



It is not an easy matter to decide whether a given animal has rabies, 

 since the symptons and the lesions given al>ove belong in part to a 

 variety of other diseases. The positive evidence that a rabid dog has 

 been near cattle would greatly assist in making a decision in doubtful 

 cases. The disease in dogs is pretty well recognized by most people, 

 but. in case a suspected dog is killed it is desirable to open the animal 

 and examine the contents of the stomach. While food is absent a 



