This is rarely observed in the horse, and unless it is sufficiently severe to produce well-marked symptoms it would not be suspected. It may occur in saddle horses from jumping, or it may be produced by falling over an embankment, or a violent fall upon the haunches may produce it. Concussion may be followed by partial paralysis or spinal hemorrhage; generally, however, it is confined to a jarring and some disturbance of the nerve elements of the cord, and the paralytic effect which ensues soon passes off. Treatment consists in rest until the animal has completely recovered from the shock. If secondary effects follow from hemorrhage or compression, they have to be treated as heretofore directed. SPINAL TUMORS. Within the substance of the cord glioma or the mixed gliosarcomata are found to be the most frequent, tumors may form from the meninges and the vertebrae, being of a fibrous or bony nature, and affect the spinal cord indirectly by compression. In the meninges we may find glioma, cancers, and psammoma, fibromata; aneurisms of the spinal arteries have been discovered in the spinal canal. _Symptoms._--Tumors of the spinal canal cause symptoms of spinal irritation or compression of the cord. The gradual and slow development of symptoms of paralysis of one or both hind limbs or certain muscles may lead to a suspicion of spinal tumors. The paralysis induced is progressive, but not usually marked with atrophy of the muscles or increased sensibility along the spine. When the tumor is within the spinal cord itself all the symptoms of myelitis may be present. _Treatment._--General tonics and 1-dram doses of nux vomica may be given; iodid of iron or iodid of potassium in 1-dram doses, three times a day in feed, may, in a very few cases, give some temporary benefit. Usually the disease progresses steadily until it proves fatal. NEURITIS, OR INFLAMMATION OF A NERVE. This is caused by a bruise or wound of a nerve or by strangulation in a ligature when the nerve is included in the ligation of an artery. The changes in an inflamed nerve are an enlargement, reddening of the nerve sheath, spots of extravasated blood, and sometimes an infiltration of serum mixed with pus. _Symptoms._--Acute pain of the parts supplied by the nerve and absence of swelling or increased heat of the part. _Treatment._--Hypodermic injections of from 3 to 5 grains of morphia to relieve pain, hot fomentations, and rest. If it is due to an inclusion of a ligature, the nerve should be divided above and below the ligature. NEUROMA, OR TUMOR OF A NERVE.