8 
ANIMAL PATHOLOGY. 
The reason why palsy in the horse is usually confined to the 
hind legs is plain. The fore limbs are attached to the trunk by 
a dense mass of highly elastic substance. This was placed be- 
tween the scapula and the ribs for the purpose of preventing 
every concussion that could be dangerous or even annoying to 
the horse or his rider. Except in consequence of a fall, there is 
scarcely the possibility of any serious injury to the anterior por- 
tion of the spine. The case is very different with regard to the 
hind limbs, and their attachment to the trunk. The femur arti- 
culates with the pelvis, and the pelvis articulates with the 
sacral continuation of the spine. The muscles of the thighs 
and haunch are capable of the most powerful exertion, and the 
greater part of them derive their origin from the bones of the 
pelvis or the spine; and these parts are necessarily liable to 
many a shock or sprain injurious to the spine and its contents. 
The lumbar and posterior dorsal portions of the spine oftenest 
exhibit those lesions which are connected with, or the cause of 
palsy, because there are some of the most violent muscular 
efforts — there is the greatest movement and the least support. 
The vertebral column — the ligaments and cartilages of the joints 
— the osseous tissue itself, is there oftenest and most extensively 
injured. The inflammation rapidly spreads to the spinal chord ; 
or, perhaps, the cord itself is compressed and injured, and its 
function can no longer be discharged. Many other causes of 
palsy may be assigned as it regards other animals ; but it may 
be taken as an axiom to regulate our practice, that in the horse 
it most frequently proceeds from disease or injury of the spine. 
Palsy ref errible to Lesion of the Spine . — If you inquire into the 
history of the cases that come before you, you find that the horse 
had fallen, and had suddenly become paralytic — or palsy had 
supervened a few days after the accident — or he was seized in 
the midst of his work, and when his energies were too cruelly 
taxed — or he had been worked exceedingly hard a few days be- 
fore, and there had been a heavy load — or the pace had been 
greater than usual — or, covered with perspiration, the horse had 
been left exposed to the cold and wet. 
I am speaking of cases as they generally occur. Palsy has 
been produced by aneurism of the posterior aorta, excessive 
bleeding, or the omission of the usual evacuations, inversion of 
the rectum, intestinal irritation, whether from worms or super- 
purgation, lesion of the muscles of the thigh, fracture of the 
scapula. Colts, one or two years old, neglected, exposed, feed- 
ing on low marshy ground, and others at the period of weaning, 
especially if the mother has been ill-fed, are subject to attacks 
