700 Enzootic Spinal Paralysis of the Horse. 



probably be onh^ recognized by microscopic examination. Tliere 

 is no cellular infiltration (Perucci). In some cases there are no 

 macroscoi^ic lesions. 



Symptoms. Clinically the disease, according to Schlegel, 

 passes through an occult and an open stage, while Perucci dis- 

 tinguishes between a peracute, an acute and a subacute form. 

 The subacute form described by Perucci corresponds with the 

 occult stage of Schlegel. 



In the occult stage there is emaciation, weakness, languor 

 and loss of power in the hind quarters, the gait being uncertain 

 in consequence. Stumbling, paddling with the hind feet, cramp- 

 like contractions of the muscles of the loins, croup and a])domen 

 are observed frequently. In some outbreaks there is slight 

 edema of the sheath and vulva, in which case there is often a 

 sediment in the urine. 



The open stage commences with collapse of the patient dur- 

 ing w^ork or movement, or in some cases while the animal is at 

 rest (peracute form). In many cases the lumbar paralysis de- 

 velops in stages and is complete wdthin some hours or two or 

 three days (acute form). The animal is only able to get up with 

 help or not at all. In cases in wdiich the paralysis is not yet 

 complete the animals paddle wdth the hind feet, keep getting 

 up and lying down again, and groan. The appetite is not dis- 

 turl)ed and, according to Perucci, there is no elevation of tem- 

 perature. By this time bile-staining of the conjunctiva is 

 usually recognizable and shortly after a rise of temperature 

 {4V to 42° C.) and a notable acceleration of the pulse. There 

 is strangury and the urine often appears red in color and con- 

 tains albumen, red blood corpuscles and bile pigments. There 

 are no obvious sensory disturbances and there isno paralysis of 

 the sphincters; the only authors to record these symptoms be- 

 ing Duvinage and Perucci. In the later stages of the disease 

 there is marked emaciation. 



In certain outbreaks, inflammatory lesions of the external 

 genital organs have been observed. The penis hangs out of 

 the sheath which is swollen and edematous, its outer surface 

 being beset with minute hemorrhages ; the lips of the vulva gape 

 and the mucous membrane of the vagina is intensely red in 

 color. Sometimes the edema extends to the perineal region. 



Course. This differs in different outbreaks. The dura- 

 tion of the disease may vary from one or more days to a week 

 in some cases, and in others from several weeks to three months, 

 so that an acute, a sul)acute and a chronic course may be dis- 

 tinguished. According to Schlegel the disease is fatal in the 

 majority of cases (70 to 100 per cent), but other authors have 

 recorded recovery in 50 per cent of cases, especially in the oc- 

 cult stage of the disease. Convalescence is slow. 



