PARALYSIS 421 



its mouth was thrust deeply into the water. It could walk, but could 

 hardly sustain itself after but a short exercise. On the fourth day the 

 animal was unable to stand, sank down, and after several ineffectual 

 struggles to rise, rolled over and lay upon its right side. Its pulse 

 and respiration remained undisturbed. It died on the seventh day. 



PARAPLEGIA— SPINAL PARALYSIS 



Paraplegia indicates some disorder of the spinal cord, and consists of 

 paralysis of the posterior half (more or less) of the body. The extent 

 of the disablement will depend upon the seat of the disease, being greater 

 in proportion as it is situated in a forward direction. Injury affecting the 

 spinal cord in the region of the back or loins would paralyse the hind- 

 quarters equally or unequally, but if it occurred in the neck, the fore and 

 the hind limbs also, and the rest of the trunk behind the damaged cord, 

 would also be deprived of the power of motion. Paraplegia in the 

 horse is most commonly the result of injury inflicted on the dorsal or 

 lumbar portion of the cord or its membranes, as when from some cause 

 the latter become thickened and unduly press upon the former, or when 

 they contain large quantities of fluid as the result of injury. 



Bony growths projecting inwards from the spine sometimes press upon 

 the cord and cause paralysis, or the same results may follow dislocation of 

 the vertebrae. 



Rarely spinal paralysis is due to causes originating in organs quite 

 away from the spine, as when mares suffer during osstrum, or foals in 

 consequence of worms in the bowels. This is termed " reflex paralysis", 

 a form of the disease from which animals affected frequently recover. 

 Here uterine irritation in the one case, and intestinal irritation in the 

 other, is the cause of the failure of the spinal cord to innervate the 

 muscles. 



Symptoms. — In paraplegia there is more or less complete paralysis 

 of the hind-quarters. When it is complete the animal occupies a re- 

 cumbent posture and is unable to rise. When the skin of the paralysed 

 region is pricked with a pin there is usually no sign of feeling, but in 

 some instances the paralysis may be almost exclusively that of motion, 

 while sensation remains intact, in which case the prick will be felt and 

 expressed by the animal's movements in front. The urine may be dis- 

 charged involuntarily, and the faeces too may escape in consequence of 

 paralysis of the sphincter ani. 



In incomplete paraplegia the hind-quarters roll from side to side, the 

 animal crosses his hind-limbs, sometimes trails the toes, or knuckles over 



