490 
PARALYSIS OF THE HIND EXTREMITIES. 
vertebrae, disease of the inter-vertebral discs, or still more frequently 
muscular disease, which may be of a rheumatic character, due to chill, 
or of purely mechanical origin. In the horse the latter is more frequent, 
because in it violent, intrinsic or extrinsic, over-extension of muscle 
produced during heavy and unwonted exertion is common. When 
animals are continuously overworked, permanent interference with 
muscular function in time results, causing the mechanical efficiency of 
the muscle to become impaired. The resulting disturbance has been 
referred to disease of the fasciie, but the truth of this statement has 
never been satisfactorily established. The pathological changes would 
here be similar to those in tendons, but, as the disease is so much 
more obdurate, it appears doubtful whether the fascia plays such an 
important part. 
Yollers describes a form of paraplegia which suddenly developed in a mare 
after parturition, simultaneously with deformity of the spinal column, between 
the 14th and 15th dorsal vertebrae. The animal could stand, but could only 
walk with difficulty; it made rolling movements with the hind-quarters. At 
first, movement was greatly interfered with, but afterwards improved, though 
the spinal deformity continued. Johow saw a fifteen year old horse which 
had suffered from weakness of the hind-quarters for a period of six months. 
The difficulty was greatest in the morning on getting up and making the first 
few steps. One day complete paraplegia suddenly set in. The body of the 
first lumbar vertebra was found, on post-mortem, to be one-third thicker than 
that of the others. The thickening encroached on the vertebral canal and 
pressed on the spinal cord, which had correspondingly diminished in 
thickness. 
Harms found the connection between the anterior ends of the glutei 
maximi and the longissimus dorsi torn away on both sides in a four year old 
horse. When resting, nothing remarkable could be seen, but during move¬ 
ment the hind-quarters rolled from side to side. A large cavity could be 
seen on either side of the spinal column, at the point where the large gluteus 
arises from the longissimus dorsi. In front of the ilium an elevation was 
noticeable. After movement, the anterior end of the large gluteus returned 
to its normal position, as could easily be seen. No improvement occurred. 
Prognosis in complete paraplegia is unfavourable, and only those cases 
due to concussion of the cord have any chance of recovery. In large 
animals the prognosis is much less favourable than in small ones, the 
former always dying at an early stage from decubital gangrene, and 
horses even sooner than cattle. 
In incomplete paraplegia, the prognosis naturally depends principally 
on the nature of the causative disease process. Eecent and sudden 
cases, especially those resulting from chill, offer more hope of recovery 
than the more chronic, which are generally due to some incurable 
disease. All forms of paralysis, distinguished by degenerative changes 
of tissue and well-developed muscular atrophy, are unfavourable; in 
these recovery is exceptional. The condition usually becomes gradually 
