It is often difficult to distinguish between spinal myelitis and meningitis in the lower animals, and the danger of confusion is greater because the two affections are often conjoined. Attacks appear to be often associated with microbian invasion of the membranes, but in its turn this is often favored by the lowered tone of the membranes through mechanical injury, circulatory disorder, trophic changes, or the action of poisons in the blood. Thus the condition may supervene on fractures, partial dislocations or sprains of the neck, back or loins, abscesses pressing on the spine, extension of septic inflammation from poll evil, fistulous withers, or arthritis of the vertebræ, penetration of the membranes by sharp pointed bodies (Reindl found a darning needle in a cow’s spinal canal), invasion by microbes in influenza, brust-seuche, dourine, rabies, milk sickness, distemper, pyæmia, septicæmia, strangles, louping ill, or Texas fever. The toxins of tetanus may start similar trouble. The larva of cysticercus cellulosa may cause meningitis in dogs or pigs, the sclerostoma in the soliped, the filaria in dogs and strongle in a variety of animals. Tubercle of the meninges is not unknown, and rheumatism is alleged as a cause. Neoplasms commencing in the cord act in a similar way, and the poisons of rye grass, millet, loco, lupins, tares and vetches may act on the membranes as well as on the myel. _Symptoms._ In the main these resemble those of myelitis and are often present at the same time, and it is only necessary to note those which are especially pathognomonic. The early rigors are followed by stiffness of the back shown in rising or walking and aggravated by motion. There may be tonic contraction of the dorsal and lumbar muscles amounting at times to oposthotonos. The muscles of the limbs, chest or abdomen or some part of them may be the seat of tonic or clonic spasm. The skin is usually hypersensitive and this is aggravated by heat. The urine is liable to be retained because of the pain of stretching to micturate. Paralysis usually follows and implies extension to the myel, compression of the cord by reason of exudation, or implication of the spinal nerves at the points of exit. In myelitis on the other hand the spasms may be entirely absent, and paralysis sets in early and extends rapidly according to the seat and extent of the lesion. _Treatment._ This will be along the same lines as in myelitis, being aimed at elimination of toxic matters, and the counteracting of the existing inflammation. Anodynes such as bromides and chloral and cold water or ice are especially called for to alleviate pain and hyperæsthesia, and antispasmodics like ether, chloroform, chloral, belladonna, etc., to allay the spasm. Saline purgatives too, and diuretics may be availed of to limit effusion and favor reabsorption. In the advanced stages iodine may be freely applied to the spine, and an occasional electric current, or cauterization may be availed of.