DISEASES OF THE NERVOUS SYSTEM 413 



suffering from an apoplectic fit, while the use of stimulants might be 

 resorted to when the more urgent symptoms have ceased. 



In all cases where the power to swallow exists, a strong dose of physic 

 should be promptly administered. 



CRIB-BITING 



In connection with diseases of the nervous system it is necessary to 

 refer to certain abnormal actions commonly described as nervous habits, 

 which are not usually recognized as diseases, but which, as they are not 

 normal, i.e. are not in accordance with the rule as applied to the actions 

 of healthy animals, must be classified as abnormal. 



"Cribbing" or "tic", "wind-sucking", and "weaving" may be taken 

 as examples of diseases which are more or less connected with some 

 ill-defined derangement of the ner- 

 vous system. Tic or cribbing has 

 been carefully studied in its various 

 forms by Continental veterinarians. 

 Friedrich Berger and Frohne, in 

 their work on the pathology of the 

 domestic animals, allude to the 

 causes of cribbing as being complex 

 and variable in their nature. Idle- 

 ness is said to be one cause of the 



acquirement of the habit. Horses, Fig. i79.-Throat^tra P for crib-biting 



like other creatures, are supposed 



to invent some kind of pastime when left alone in a stall or box, and 

 the manger, drinking-trough, or piece of chain or rope lends itself to 

 this kind of indulgence. In the case of some animals it seems that no 

 assistance from external objects is necessary, as they succeed in per- 

 forming the actions of a crib-biter without seizing the manger with 

 their teeth or obtaining any other support. By contracting the muscles 

 of the neck they contrive to keep the head in a fixed position, and can 

 make the peculiar noise which is common to crib-biters. 



Among the causes of cribbing heredity is referred to as having con- 

 siderable influence. Horses it is said become crib-biters and wind-suckers 

 apparently from imitation, although it would seem that a certain amount 

 of nervous excitability is necessary as a predisposing cause, as it may be 

 that only one animal out of a very large number which are exposed to 

 the same temptation acquires the habit. 



The habit of cribbing or wind-sucking has somewhat fancifully been 



