10 BUKEAU OF ANIMAL INDUSTKY. 



It is important to know, first of all, something of the origin and 

 development of the disease, therefore the cause should be looked for. 

 The cause of a disease is important, not only in connection with diag- 

 nosis, but also in connection with treatment. The character of food 

 tiiat the horse has liad, the use to which he has been put, and the kind 

 of care he has received should all he inquired into closel3\ It ma}^ be 

 found by this investigation that the horse has been fed on damaged 

 food, such as brewers grains or moldy silage, and this may be suffi- 

 cient to explain the profound depression and weakness that are char- 

 acteristic of forage poisoning. If it is learned that the horse has 

 been kept in the stable without exercise for several days and upon 

 full rations, and that ho became suddenly lame in his back and liind 

 legs, and finally fell to the ground from what appeared to be partial 

 parahsis, this knowledge, taken in connection with a few evident 

 symptoms, will be enough to establish a diagnosis of azoturia. If it 

 is learned that the horse has been recently shipped in the cars or has 

 been through a dealer's stable, we have knowledge of significance in 

 connection with the causation of a possible febrile disease, which is, 

 under these conditions, likeh' to prove to be inliucnza, or edematous 

 pneumonia. 



It is also important to know whether the particular horse that is 

 under examination is the only one in the stable or on the premises 

 that is similarly afflicted. If it is found that several horses are 

 atflicted much in the same way, we have evidence here of a common 

 cause of disease which may prove to be of an infectious nature. 



Another item of importance in connection with the history of the 

 case relates to the treatment that the horse ma}- have had before he 

 is examined. It sometimes happens that medicine given in excessive 

 quantities produces symptoms resembling those of disease, so it is 

 ijuportant that the examiner shall be fully informed as to the medica- 

 tion that has been emploj^ed. 



ATTITUDE AND GENERAL CONDITION. 



Before beginning the special examination, attention should be paid 

 to the attitude iind general condition of the animal. Sometimes horses 

 assume positions that are characteristic of a certain disease. For 

 example, in tetanus, or lockjaw, the muscles of the face, neck, and 

 shoulders are stiff and rigid, as well as the muscles of the jaw. This 

 condition produces a peculiar attitude, that once seen is subsequently 

 recognized as rather characteristic of this disease. A horse with 

 tetanus stands Avith his muscles tense and his legs in a somewhat brac- 

 ing position, as though ho were gathered to repel a shock. The neck 

 is stiff and hard, the head is slightl}^ extended upon it, the face is 

 drawn, and the nostrils arc dilated. The tail is usually held up a 



