Symptoms. 615 



Sensibility may be increased at the outset but later, and not 

 rarely from the beginning, gradually decreases in proportion to 

 the dullness. In certain parts of the body, neck, along the ver- 

 tebral column, etc., there may be pronounced hyperesthesia up 

 to the last. Animals show this increased sensitiveness by rub 

 bing or biting the particular parts. Reflex irritability is in 

 creased at the commencement and this may persist throughout. 

 Slight external stimuli are sufficient to cause spasms of certain 

 muscles and even general cramp. In entire animals and even 

 in castrated animals there may be frequent or persistent erec- 

 tions, and in mares the corresponding symptoms are seen. 



In some cases there is paralysis. Paralysis of the muscles 

 of the face causes distortion of the features. The tongue hangs 

 out of the mouth and swallowing is impossible. In many cases 

 there is weakness of the hind quarters. 



The temperature is variable, but is, as a rule, somewhat ele- 

 vated, and in the horse oscillates between 39° and 39.5° C. Ex- 

 traordinarily high temperatures are onlj^ rarely encountered. 

 In one case observed by Mergel and Knabe the temperature 

 was 41° C, and in one seen by Ekkert 41.6° C. It commonly 

 happens that there is a rise of temperature at the outset only, 

 there being a fall to the normal afterwards. Sometimes the 

 temperature rises to a marked extent at long- intervals. Per- 

 sistent high temperature indicates a complication of some sort. 



The rate and rhythm of the heart's action are variable, com- 

 paratively slight external stimuli causing marked acceleration. 

 Marked and persistent acceleration of the pulse indicates either 

 a complication or paralysis of the vagus. Respiration may be 

 either more rapid or slower than in normal animals. 



Appetite is, as a rule, poor from the outset. Prehension of 

 food is rendered difficult, owing to cramp of the lips and muscles 

 of mastication and paralysis of the pharynx. Diseased horses 

 are unable to use their lips in the prehension of food and they 

 bite right into the food, mastication being frequently inter- 

 rupted. There is constipation and the abdomen appears 

 drawn in. 



In the later stages the gait is verj uncertain, and in some 

 cases movement is impossible, the animal lying unconscious on 

 the ground. Respiration is shallow and rattling and sometimes 

 of the Cheyne-Stokes type, the limbs are extended and are 

 sometimes moved in the horizontal direction (socalled swim- 

 ming movements). There may or may not be symptoms of 

 paralysis or cramp at the time of death. The immediate cause 

 of death may also be due either to general sepsis following bed 

 sores, pneumonia due to foreign bodies or fracture of the skull. 



According to Kiihn, the symptoms of Borna disease are very va- 

 riable. In some cases there is hemiplegia, in others rapidly progressive 

 paralysis of the lips, tongne and pharynx; and in still others, a striking 

 change in the disposition of the animal, previously quiet horses becom- 

 ing vicions (as seen in a case by Kalkhoff). Now and then, horses will 



