268 SWINE PRACTICE 



The paralysis usually involves the hind legs, though in some in- 

 stances the front legs may be affected. An occasional case has been 

 observed in which both the front and hind legs were simultaneously 

 affected. After the disease has progressed for some time the muscles of 

 the affected portions become tense and hard. Complications due to 

 the constant decubitus usually develop in the course of time and the 

 affected animal dies. 



Treatment. — Paralysis due to alterations in the motor nerves is ap- 

 parently incurable. Inbreeding and inheritance are factors in the 

 cause of paralysis, and the condition may be prevented by outcross- 

 ing and eliminating all breeding animals in which a noticeable per- 

 centage develop the disease. Medicaments excepting general tonics 

 or laxatives as indicated are apparently of little or no value. If the 

 affected swine are in good condition it is economy to slaughter them 

 before complications arise, as the paralysis does not damage the meat. 



CIIORE.\ 



Chorea is a neurotic condition characterized by rapid contractions 

 of muscles or groups of muscles. 



Etiology. — In many instances chorea appears to be purely func- 

 tional. Some have attributed it to thrombosis; toxic substances may 

 be a factor in producing it, and in some cases malnutrition pre 

 disposes and possibly excites the condition. 



No constant tissue change has been identified with chorea. 



Symptoms. — Twitching of muscles or group of muscles more or less 

 continuously except during sleep characterizes chorea. The disease 

 may be outgrown in the course of one or two months, or it may be- 

 come chronic. 



Treatment. — ^Various drugs have been recommended to relieve this 

 condition, but the best plan is to destroy pigs that have aggravated 

 eases, and to fatten and market those having mild attacks. 



CEEEBRAL HYPEREJIIA 



Hyperemia no doubt occurs in the brain and meninges of swine, 

 but such cases have received meager clinical investigation. A few 

 eases of purulent cerebritis, or staggers, have been observed. Some 

 of these cases were caused by wormeaten, moldy corn, or at least no 

 new cases appeared after changing the feed. The cerebral tissue was 

 affected and the lesion consisted of a liquefying necrosis, the necrotic 

 area usually occurring in relation to the lateral ventricle and being 



