DISEASES OF THE NERVOUS SYSTEM. 233 
twice a day. To strengthen the system, iodid of iron 1 dram twice a 
day and 1 dram of nux vomica once a day may be given in the feed. 
Electricity to the paralyzed and weakened muscles is advisable; the 
current should be weak, but be continued for half an hour two or 
three times daily. If the disease is due to a broken back, caries of 
the vertebrz, or some other irremediable cause, the animal should be 
destroyed at once. 
MYELITIS, OR INFLAMMATION OF THE SUBSTANCE OF THE 
SPINAL CORD. 
This is a rare disease, except as a secondary result of spinal menin- 
gitis or injuries to the spine. Poisoning by lead, arsenic, mercury, 
phosphorus, carbonic-acid gas, etc., has been known to produce it. 
Myelitis may be confined to a small spot in the cord or may involve 
the whole for a variable distance. It may lead to softening abscess 
or degeneration. 
Symptoms.—The attack may begin with a chill or convulsion; the 
muscles twitch or become cramped very early in the disease, and the 
bladder usually is affected at the outset, in which there may be either 
retention or incontinence of urine. These conditions are followed by 
complete or partial paralysis of the muscles posterior to the locality 
of the inflamed cord, and the muscles begin to waste away rapidly. 
The paralyzed limb becomes cold and dry, due to the suspension of 
proper circulation; the joints may swell and become edematous; 
vesicular eruptions appear on the skin; and frequently gangrenous 
sloughs form on the paralyzed parts. It is exceedingly seldom that 
recovery takes place. In a few instances it may assume a chronic 
type, when all the symptoms become mitigated, and thus continue 
for some time, until septicemia, pyemia, or exhaustion causes death. 
Pathology—tThe inflammation. may involve nearly the whole 
length of the cord, but generally it is more intense in some places 
than others; when due to mechanical injury, the inflammation may 
remain confined to a small section. The cord is swollen and con- 
gested, reddened, often softened and infiltrated with pus cells, and 
the nerve elements are degenerated. 
Treatment.—Similar to that of spinal meningitis. 
SPINAL CONGESTION. 
This condition consists in an excess of blood. As the blood vessels 
of the pia mater are the principal source of supply to the spinal 
cord, hyperemia of the cord and of the meninges usually go together. 
The symptoms are, therefore, closely allied to those of spinal menin- 
gitis and congestion. When the pia mater is diseased, the spinal 
cord is almost invariably affected also. 
