PALSY IN THE HORSE. 
665 
but the horse, except from some visit to the oat-bin, or other as 
gross mismanagement, is rarely apoplectic ; and when he is, there 
is seldom that degree of plethora which gives to apoplexy its 
greatest danger. There are, indeed, cases recorded of two 
stallions that became paralytic after covering too many mares; 
they became apoplectic first, and there was probably considerable 
efi'usion of blood on the base of the brain. This kind of palsy 
follows some change in the structure or functions of the brain, 
long visible enough in the loss of temper and the decline of intel¬ 
lect, or it may be attributed to some moral influence or mental irri¬ 
tation. The horse has scarcely brain or intellect enough for this. 
Palsy is produced by some injury inflicted on the brain or its 
membranes, but the brain in our patients has either a second plate 
of bone of great thickness, or a thick mass of muscle given for 
its protection. 
Palsy in our patients proceeds from injury of the spinal chord, 
and that chord is more developed ; it is larger than in the human 
being. It is more exposed to injury—injury which will affect 
not one side only, but the whole of the chord at the injured part. 
It is also an anatomical fact, that the decussating fibriculi which 
extend from one motor column to the other, and connect the two 
together in consentaneous action in the animal whom we often 
tax so severely, and whose utility to us consists principally in his 
muscular strength, are far larger in the horse than in man ,* and, 
by means of these connecting fibres, disease also is more likely 
to spread from side to side. It is on these accounts that while 
hemiplegia is the form which palsy oftenest assumes in the 
human being, paraplegia, or palsy equally affecting both sides, 
is the most frequent malady of the quadruped. 
The Hind Extremities ckiejiy .—Palsy in the horse generally at¬ 
tacks the hind extremities. The reason of this is plain. The 
fore limbs are attached to the trunk by a dense mass of highly 
elastic substance. This was placed between 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 portion of the spine. The case is 
very different with regard to the hind limbs, and their attach¬ 
ment to the trunk. The femur articulates 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 [)ostcrior dorsal portions 
