'50 C.mhinc.l ]\inilysis ..T tlic Tail and ..f the Spliiiicli 



15. Combined Paralysis of the Tail and of the Sphincter. 



In the horse a condition is sometimes observed whicli is 

 characterized hy paralysis of the spliincters of the anns and 

 bladder with simnltaneons paralysis of the tail. The canse of 

 this condition is a chronic interstitial nenritis of the canda 

 eqnina. 



Occurrence. The disease, which has been known for a lon^sf 

 time, is confined to the horse. Marek's observations do not con- 

 firm those of several anthors who state that the disease occnrs 

 most frequently in mares. In Marek's observations 50% of 

 the cases were in mares. 



Etiology. Chronic inflannnation of the canda eqnina is 

 caused by mechanical inflneuces. This may be severe and act 

 only once, or it may be slight and be in action for long periods 

 or come into action repeatedly, and may involve the mobile 

 candal vertebrae or even the sacrnm. 



Wolff has frequently seen the condition result from fracture of the caudal 

 vertebrae and Marek has seen one similar case. Jn a case reported by Eubay fracture 

 of the sacrum led to chronic inflammation of the eauda equina, and in one ob- 

 served by Kuske and ]\Iarek the horse received an injury to the croup during trans- 

 port by rail. Marek observed the occurrence of the disease in a mare shortly after 

 copulation, in two horses after falling on the buttocks, and in a further case a 

 horse that was in somewhat poor condition had to l)e helped to rise by lifting on 

 the tail. In a case observed by Mayerstrasse there was also facial paralysis but 

 this in all probability was due to bruising while the animal was down. 



Injuries to the croup or tail may obviously lead to bruising and consequent 

 temporary paralysis of the caudal nerves or may lead to the i)roduction of clinical 

 symptoms of neuritis of the cauda equina. 



Anatomical Changes. The nature of the disease was eluci- 

 dated by the thorough investigations of Dexler and his results 

 have been confirmed completely by other authors (Cadeac, 

 Raymond, Rubay, Hutyra and Marek). According to these in- 

 vestigations the nerve roots in the vertebral canal posterior to 

 the end of the spinal cord and outside the dura mater are em- 

 bedded in a fibrous connective tissue which takes the form of 

 an elongated and often asymmetrical swelling, filling up the 

 sacral canal (figs. 110-111) and which extends into the inter- 

 vertebral spaces. In many cases one or more nerve trunks 

 leading to the brain are wholly or partly free but appear much 

 thickened. As a rule the inflammation does not extend further 

 forwards than the second or first sacral nerve roots, but in a 

 few cases the last two lumbar nerve roots were involved. Ex- 

 ceptionally the process involves the subdural section of the 

 nerve roots and even the pia mater of the cord. In recent 

 cases the connective tissue appears gelatinous, red in color or 

 beset with numerous hemorrhages (fig. 110). 



Under the microscope it is seen that the nerve fibers are closely surrounded 

 by newly formed connective tissue. This tissue is very finely fibrolated and at 



